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HP 8550 Service Manual

HP 8550 - Color LaserJet Laser Printer Manual

HP 8550 manual table of contents:

  • HP 8550 | Service Manual - Page 1
    8550 Printer Copy Module Automatic Document Feeder High-Capacity Input Service Manual English
  • HP 8550 | Service Manual - Page 2
  • HP 8550 | Service Manual - Page 3
    HP Copy Module, ADF, and side HCI for HP Color LaserJet 8550 series printers _____ Service Manual
  • HP 8550 | Service Manual - Page 4
    ...contained in this document is subject to change without notice. Hewlett-Packard makes no warranty of any ... OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Hewlett-Packard shall not be liable for any ... to properly grounded (3-hole) wall outlets. Hewlett-Packard Company 11311 Chinden Boulevard...
  • HP 8550 | Service Manual - Page 5
    ... serial numbers ...35 Safety and regulatory information ...35 2 Service approach Chapter contents ...37 Service approach overview ...39 Parts and supplies ...39 Ordering ... functionality ...51 Self-diagnostic messages ...59 Service mode ...60 4 Adjustments and maintenance Chapter ...
  • HP 8550 | Service Manual - Page 6
    ... ...535 8 Parts and diagrams Chapter contents ...547 How to use this chapter...551 Printer parts unique to the HP Color LaserJet 8550MFP ...552 Stand ...555 Copy module ...558 ADF ...600 Side HCI ...649 Numerical parts list ...672 Alphabetical ...
  • HP 8550 | Service Manual - Page 7
    ...of side HCI ...34 Copy module control panel ...49 Service mode initial screen ...61 Service label (inside the lower front cover of the copy module) ...62 Example of a Level 1/Level ... BLANK margins ...123 Adjusting horizontal registration ...124 Service label ...129 Standard white plate barcode ...
  • HP 8550 | Service Manual - Page 8
    ... ...159 Base plate securing screws ...160 Paper guide fixing screws ...161 Paper guides ...... Reflecting face sensor ...170 Registration sensor ...170 Guide plate ...171 Registration sensor ...171 Registration ... ...172 Light-emitting face ...172 Separation guide ...173 Control panel power soft switch, ...
  • HP 8550 | Service Manual - Page 9
    ...2) ...185 A4- and letter-size, 2 copies, 4-color, Direct, and cassette 1 sequence of operations (2 ... ...188 A4- and letter-size, 2 copies, 4-color, Direct, cassette 1 sequence of operations ...189 ... matching ...210 Text identification ...211 Sensor color correction measurement ...212 Background pixel ...
  • HP 8550 | Service Manual - Page 10
    Figure 115. Figure 116. Figure 117. Figure 118. Figure 119. Figure 120. Figure 121. Figure 122. Figure 123. Figure 124. Figure 125. Figure 126. Figure 127. Figure 128. Figure 129. Figure 130. Figure 131. Figure 132. Figure 133. Figure 134. Figure 135. Figure 136. Figure 137. Figure 138. Figure 139....
  • HP 8550 | Service Manual - Page 11
    Figure 157. Delivery of originals ...264 Figure 158. Sequence of operations (reduced page composition; top pick-up) ...265 Figure 159. Delivery path ...266 Figure 160. Feeding the first original ...266 Figure 161. Delivering the first original and picking up the second original ...267 Figure 162. ...
  • HP 8550 | Service Manual - Page 12
    .... Removing the copy module upper front cover ...337 Figure 216. Removing the copy module scanner motor ...338 Figure 217. Removing the copy module the scanner motor driver PCB ...339 Figure 218. Preparing to remove the ROM DIMM ...340 Figure 219. Opening the claws ...341 Figure 220. Lifting the ROM ...
  • HP 8550 | Service Manual - Page 13
    Figure 234. Securing the metal cable clamp to the mirror 1 mount (front view) ...351 Figure 235. Securing the metal cable clamp to the mirror 1 mount (rear view) ...351 Figure 236. Cable positioning ...352 Figure 237. Copyboard glass ...353 Figure 238. Flexible cable warning label ...353 Figure 239...
  • HP 8550 | Service Manual - Page 14
    ...guide and screws ...383 Opened side guide ...383 Mounting the gear ...384 Setting ...motor ...385 Pick-up motor cable guide ...386 Detaching the pick-up motor ... motor unit ...387 Feeder motor color sensor ...387 Feeder motor drive ... Paper-retaining solenoid ...396 Inlet guide plate ...397 Pick-up roller ...
  • HP 8550 | Service Manual - Page 15
    ... ring and bushing ...409 Detaching the lower guide stopper ...409 Removing the spring ...410 Registration ... ...410 Disconnecting the sensor connector ...411 Paper guide ...411 Reversing plate (front view) ... and grounding cord ...421 Detaching the reversing guide ...421 Document tray mounting plate ......
  • HP 8550 | Service Manual - Page 16
    ...separation roller ...441 Preparing to remove the lifter wire ...442 E-ring and pulley cover ...442 Pulley cover ...443 Screw and lifter wire ...444 Parts removal behind the lifter wire ...445 Connectors ...446 Paper-detection unit ...446 Lifter drive unit ...447 Rear panel ...447 E-ring and gear ......
  • HP 8550 | Service Manual - Page 17
    ... Horizontal stripe test print ...466 256-color test print ...467 256-gradation ...64-gradation test print ...473 Full-color 16-gradation test print ...474 Full-color light area 16-gradation test print ...475 Leakage breaker ...Analog image processor PCA ...588 Motor driver PCA ...589 Inverter PCA ...590 ...
  • HP 8550 | Service Manual - Page 18
    ... ...630 Paper feed motor assembly ...632 Belt drive motor assembly ...634 Upper paper guide assembly ...636 Lower paper guide assembly ...638 Separation roller assembly ...640 Paper separation assembly ...642 RDF controller PCA ...644 Connectors (1 of...
  • HP 8550 | Service Manual - Page 19
    ...specifications-ADF ...29 Physical specifications-ADF ...29 Supported media-ADF ...29 Operating conditions-side ...Physical specifications-side HCI ...32 Ordering parts ...40 Technical support websites ...40 Asia Pacific ... ...56 Self-diagnostic (error) messages ...59 Service mode sub-items ...60 Copier, ...
  • HP 8550 | Service Manual - Page 20
    ... Copier counter menu descriptions ...111 Copier, counter mode Level 2 and Level 3 menus . . 112 Feeder options ...115 Serviceable printer parts ...119 Feeding power measurements ...154 Periodically replaced parts ...163 Items to be cleaned ...166 Lubricants ......
  • HP 8550 | Service Manual - Page 21
    ... switches and LEDs...319 User LED...320 Signal names and codes ...321 Service tools ...331 Test pattern types ...465 Common image faults ...476 Repetitive... ...586 Reader controller PCA ...587 Analog image processor PCA ...588 Motor driver PCA...589 Inverter PCA ...590 Connectors (1 of 3) ...591 EN ...
  • HP 8550 | Service Manual - Page 22
    ......633 Belt drive motor assembly ...635 Upper paper guide assembly ...637 Lower paper guide assembly ...639 Separation roller assembly ...641 Paper separation assembly...643 RDF controller... ...667 Deck controller PCA ...668 Connectors ...669 Numerical parts list ...672 Alphabetical parts ...
  • HP 8550 | Service Manual - Page 23
    1 Product information Chapter contents Introduction ...23 Copy module ...23 Features ...23 Specifications ...24 Overview ...26 Automatic document feeder (ADF) ...28 Features ...28 Specifications ...29 Overview ...30 Side high-capacity input (side HCI) ...32 Features ...32 Specifications ...32 ...
  • HP 8550 | Service Manual - Page 24
    22 Chapter 1 - Product information EN
  • HP 8550 | Service Manual - Page 25
    Introduction The HP Color LaserJet 8550 Multi-Function Printer (MFP) system consists of the following: l l l l l Copy module Stand Print engine ... image, darken image, highlight reproduction, old-fashioned photo) Color adjust (color balance, density range YMCK adjustment) ...
  • HP 8550 | Service Manual - Page 26
    ... Heavy-sheet original Image creation l l l l l l l l l Image shift Margin Color balance Sharpness Single color... Size A4, Letter A4, Letter A4, Letter 4-color 34 50 57 Mono-color 18 35 41 *Times shown assume A4-size media, direct ...17, Legal, Letter A4/LTR 4-color 3 ppm Mono-color 12 ppm 6 ppm ...
  • HP 8550 | Service Manual - Page 27
    ... 50 Hz ± 2 Hz 1.5 kW or less Physical Table 5. Physical specifications-copy/print Weight Dimensions (mm) 39 kg (348 lb) Width: 673 mm (26.5 in) Height: 190 mm (7.5 in) Depth: 787 mm (31.0 in) Supported media sizes l l l l A3 A4R A4 legal l l l l B4 B5 11-by-17 inches letter EN Copy module 25
  • HP 8550 | Service Manual - Page 28
    ... front left 1 2 3 4 Copyboard cover Copyboard glass Control panel Power supply cooling fan air inlet 2 1 2 2 3 2 4 Figure 2. Copy module front right 1 2 3 4 Control key switch Power supply cord connector Rear power switch Printer power cord connector 26 Chapter 1 - Product information EN
  • HP 8550 | Service Manual - Page 29
    2 2 4 2 5 2 6 2 3 Figure 3. 1 2 3 4 5 6 2 1 Copy module cross-section Number 1 mirror Number 2 mirror Number 3 mirror Scanning lamp Lens Charge-coupled device (CCD) EN Copy module 27
  • HP 8550 | Service Manual - Page 30
    Automatic document feeder (ADF) The ADF is not part of the standard MFP bundle. It can be ordered as an option. Features The ADF can identify the size of an original in terms of its length (feeding direction) and width for communication to its host...
  • HP 8550 | Service Manual - Page 31
    ... tray. Width: 641 mm (25.2 in) Height: 152 mm (6.0 in) Depth: 508 mm (20.0 in) Dimensions do not include document output tray. Dimensions Supported media Table 8. Supported media-ADF Sizes A5, B5, A4, Letter, Legal B4, A3, 11 by 17, Legal Weights 50 to 105 g/m 2 Capacity 50 sheets 25 sheets 50 ...
  • HP 8550 | Service Manual - Page 32
    Overview 2 1 2 2 3 2 4 2 5 Figure 4. Automatic document feeder 2 6 2 7 2 8 1 2 3 4 Upper cover Side guide Last-page detector Original-set indicator 5 6 7 8 Document tray Sub-tray Body cover Document output tray 30 Chapter 1 - Product information EN
  • HP 8550 | Service Manual - Page 33
    ...-section 1 2 3 4 5 6 7 Reversing roller Paper deflecting plate Feeding roller (separation function) Separation belt (feeding function) Pre-separation guide Delivery/pick-up roller Paper retaining plate 8 9 Pick-up roller Delivery roller 10 Feeding belt link roller 11 Retaining rolls 12 Feeding ...
  • HP 8550 | Service Manual - Page 34
    Side high-capacity input (side HCI) Features l l l holds up to 1,000 sheets of 20-pound (lb) media supports media weights of 64 g/m2 to 105 g/m2 accommodates either letter- or A4-size media Specifications Environmental Table 9. Operating conditions-side HCI Temperature Humidity Atmospheric ...
  • HP 8550 | Service Manual - Page 35
    Overview 2 2 3 2 1 Figure 6. Front of side HCI 1 2 3 Upper right cover Paper-size selection tab User LED 2 4 2 5 Figure 7. Rear of side HCI 4 5 Interface connector Power receptacle EN Side high-capacity input (side HCI) 33
  • HP 8550 | Service Manual - Page 36
    2 1 2 2 3 2 4 2 5 Figure 8. Cross-section of side HCI 1 2 3 4 5 Feed roller Pick-up roller Paper-size limit panel Separation roller Lifter 34 Chapter 1 - Product information EN
  • HP 8550 | Service Manual - Page 37
    Model and serial numbers The serial number on the HP Color LaserJet 8550MFP is the primary identification number for this MFP bundle. The serial number is located on the back ... 11311 Chinden Boulevard Boise, Idaho 83714-1021 USA Color LaserJet 8550MFP Accessories C7836A, C7837A, and C7839A ...
  • HP 8550 | Service Manual - Page 38
    .../TV technician. Note Any changes or modifications to the printer that are not expressly approved by HP could void the user's authority to operate this equipment. Use of a shielded interface cable is required to comply with the Class B limits of Part 15 of FCC rules. 36 Chapter 1 - ...
  • HP 8550 | Service Manual - Page 39
    ...FIRST ...43 Dealer Response Line ...44 HP Software Distribution Center...44 HP Direct ...44 Customer Support Sales Center...44 Parts identification ...44 Customer Information Centers ...44 HP Customer Care Centers (CCC) ...45 Warranty...46 ...
  • HP 8550 | Service Manual - Page 40
    38 Chapter 2 - Service approach EN
  • HP 8550 | Service Manual - Page 41
    Service approach overview The HP Color LaserJet 8550MFP has a one-year, next-day, onsite warranty from HP to the ... strategy based on field-replaceable units (FRUs) applies to all devices of the HP Color LaserJet 8550MFP system (print engine, copy module, and side HCI). The ADF under warranty will be ...
  • HP 8550 | Service Manual - Page 42
    ... Ordering parts Organization SMO (Service Materials Organization) Address Hewlett-Packard Company Support ... 13. Technical support websites HP Customer Care Online Software drivers, support documentation,...answers to frequently asked questions http://www.hp.com/go/support HP Technical Training (North ...
  • HP 8550 | Service Manual - Page 43
    ...) United Kingdom: 0734-441212 Contact your local HP Parts Coordinator for other local phone numbers. ... of stock), call the HP Customer Information Center at (800) 752-0900. Ordering FRUs This printer is ... from SMO or SME (see page 40). Parts exchange program HP offers remanufactured assemblies for ...
  • HP 8550 | Service Manual - Page 44
    ... lists by sending e-mail to the server. The list server allows HP LaserJet Technical Marketing to make the ... send e-mail to: subscribe-CLJ8500/8550-HW@chsdes1.boi.hp.com l To subscribe to software-related information... send e-mail to: subscribe-CLJ8500/8550-SW@chsdes1.boi.hp.com Once you subscribe, ...
  • HP 8550 | Service Manual - Page 45
    ...Retrieval Support Technology) is a phone-in fax service that provides technical information for HP LaserJet end-users and service personnel. Receiving a fax requires a type-3 facsimile machine... and accessory information printer support software information toner information driver request form and...
  • HP 8550 | Service Manual - Page 46
    ...further technical assistance on pre/post sales and service support, HP dealer service-authorized personnel can contact the Dealer Response ... (U.S. only) (800) 363-6584 (Canada) HP Software Distribution Center For printer drivers and application note orders: (805) 257-5565 HP Direct For supplies and...
  • HP 8550 | Service Manual - Page 47
    ... to answer technical questions at no charge for a period equivalent to the original HP hardware warranty period. Questions regarding operating systems such ...referred to your dealer. Note Each time you call the HP Customer Care Centers, you will be asked to provide the printer serial number and the ...
  • HP 8550 | Service Manual - Page 48
    ...Warranty The warranty outlines specific legal rights. Customers might also have other rights that vary from area to area. Refer to the user's guide for further warranty information. 46 Chapter 2 - Service approach EN
  • HP 8550 | Service Manual - Page 49
    ...set indicator (ADF) ...58 Warnings and actions ...58 Self-diagnostic messages ...59 Service mode ...60 Overview ...60 Navigating service mode screens ...63 Copier, display mode (DISPLAY) ...65 Copier, I/O mode (I/O) ...77 Copier, adjust mode (ADJUST)...
  • HP 8550 | Service Manual - Page 50
    48 Chapter 3 - Operational overview EN
  • HP 8550 | Service Manual - Page 51
    ... to indicate that data is being output • error (after "options")-flashes orange to indicate a printer error, the absence of media, media jam, or absence of toner 3 Screen contrast dial-adjust the contrast of the liquid crystal display (LCD) (...
  • HP 8550 | Service Manual - Page 52
    ... numeric values, such as copy counts 14 ACS key-enable and disable black-and-white/color auto identification 15 Full-color key-select four-color (full-color) mode 16 Black key-select black (mono-color) mode 17 Save power key-enable and disable Power Save mode 18 Clip holder-a ...
  • HP 8550 | Service Manual - Page 53
    ...Zoom X/Y zoom Enlarged page separation Text/photo/map Description Measures the size of the original ...quick copies of different originals. Automatically identifies a color or a black-and-white original. Print ...sided (requires duplexing unit) Interrupt copying Color auto recognition (ACS) Page separate...
  • HP 8550 | Service Manual - Page 54
    User mode The copy module provides an administrative-functions menu that allows for customized defaults to suit users' needs. Four administrative menus are available when is pressed. l l l l Common settings Copy module settings Timer settings Adjustment/cleaning The administrative-functions key ...
  • HP 8550 | Service Manual - Page 55
    ... there is no prescanning. In black mode of text/photo/map mode, selects "text original"...," text is reproduced more faithfully. In "priority on photo originals," photographs are reproduced more faithfully..../map Factory setting: priority on photo original. Save power The "rate of saving" is the rate ...
  • HP 8550 | Service Manual - Page 56
    ... the Reset key being pressed. Initializes the items of the copy module settings to factory settings. Remarks Factory settings: none Standard mode Factory setting: copy count: 1 paper select: auto density: auto original type: text/photo/map Settings reset 54 Chapter 3 - Operational overview EN
  • HP 8550 | Service Manual - Page 57
    Timer settings Table 18. Timer settings Name Auto clear time Description Automatically returns the touch-panel display to standard mode if no operation takes place for a set time after the end of key operation. Set the time to between zero and nine minutes in one-minute increments. Automatically ...
  • HP 8550 | Service Manual - Page 58
    ... and a copy image that has been made with the manual density control set at the standard (median) ... correction to any of five settings. Correct poor color balance caused by discrepancies in fine adjustment or ... through the optional ADF to pick up loose toner and other contaminants. Remarks Factory ...
  • HP 8550 | Service Manual - Page 59
    ... seconds. 6 7 8 9 Cold reset To perform a cold reset on the print engine portion of the HP Color LaserJet 8550MFP, see the HP Color LaserJet 8500/8550 Printer Family Service Manual. Cold reset on the copy module is useful in three circumstances: l l ...
  • HP 8550 | Service Manual - Page 60
    ...11-by-17 inch in feeding length, open the original sub tray. Set the side guide to suit the size of the original. The side guide lock must be removed if ... is larger than 297 mm (A4/A3). For details, see "To remove the side guide lock" on page 382. 3 4 5 Place the originals with the first page on top...
  • HP 8550 | Service Manual - Page 61
    ...a self-diagnostic (error) message appears, see the instructions on the touch panel display. If there is no message, but the HP Color LaserJet 8550MFP fails to make copies, there might be an error in the printer unit. Follow the instructions on the printer ...
  • HP 8550 | Service Manual - Page 62
    ... the user screen after the power is turned on. Start service mode when the "Wait (Select Auto Start)" or ...ID No." message appears. Overview The copy module's service mode is divided into two major items, each with its own initial screen: l l COPIER (copier service screens begin on page 65) FEEDER (...
  • HP 8550 | Service Manual - Page 63
    ... the screen shown in figure 10. Figure 10. Service mode initial screen 4 Select an item on ...touch panel. The screen for the selected item appears. To end service mode Press the Reset key to return to ...initial screen. Press the Reset key again to end service mode and return to the User screen. EN...
  • HP 8550 | Service Manual - Page 64
    ... attached behind the lower front cover of the copy module. Figure 11. Service label (inside the lower front cover of the copy module) ... the reader controller PCB, the firmware DIMM, or the dc controller PCB (on the printer), you must reenter these numbers in service mode. If you have replaced the ...
  • HP 8550 | Service Manual - Page 65
    Navigating service mode screens The screens are arranged in three layers: l l l initial screen (see figure 10 on page 61) Level 1/Level 2 screen Level 3 ... item shown across the top of the screen. To select a Level 2 item, select an item shown as white text on a black background. EN Service mode 63
  • HP 8550 | Service Manual - Page 66
    After a Level 2 item is selected, a Level 3 screen appears. Figure 13 shows the Level 3 screen that appears after COPIER, from the initial screen, and DISPLAY and VERSION, from the Level 1/Level 2 screen, are selected. If the Level 3 item consists of multiple pages, N/M appears, with N being the ...
  • HP 8550 | Service Manual - Page 67
    ... the user interface Connection status of accessories (only if installed) State of use of cassettes and multifeeder Log of jams Log of errors and alarms Measured readings of the CCD State of sensors (important in servicing) Miscellaneous other conditions Latest alarm for the ADF EN Service mode 65
  • HP 8550 | Service Manual - Page 68
    ... ROM version of the sorter driver PCB (not available on the HP Color LaserJet 8550MFP) "SORTER ... status of the sorter (not available on the HP Color LaserJet 8550MFP) Connection status of the side ... status of the editor (not available on the HP Color LaserJet 8550MFP) Connection status of the control ...
  • HP 8550 | Service Manual - Page 69
    ... 1 Media width in cassette 2 Media width in cassette 3 (supports either a 1,000-sheet side side HCI or ... code "Exxx" (to decode error codes, see Chapter 7, "Troubleshooting") Detail code (if not available, "0000...readings) AA EEEE FFFF G TARGET-B TARGET-G TARGET-R BOF-B BOF-G BOF-R EN Service mode 67
  • HP 8550 | Service Manual - Page 70
    Table 23. Copier, display mode Level 2 and Level 3 menus (continued) Level 2 item CCD, continued (when "0" is set to COPIER > OPTION > BODY > SH-SW) Level 3 item OFST-OB OFST-OG OFST-OR OFST-EB OFST-EG OFST-ER GAIN-OB GAIN-OG GAIN-OR GAIN-EB GAIN-EG GAIN-ER Description Offset level (SH-SW = 0) of...
  • HP 8550 | Service Manual - Page 71
    ... display mode Level 2 and Level 3 menus (continued) Level 2 item SENSOR Level 3 item SC-HP W-TONER DOC-SZ DRUMLIFE Description Output of ...stable image guarantee range for the printer (0 = normal, 1 = error) Check the sensors and the condition of the intermediate transfer drum. If ...
  • HP 8550 | Service Manual - Page 72
    Copier, display mode, user > language details Table 24. Country code Code IT US SG GB Country Italy North America General United Kingdom Code AU FR DE NL Country Australia France Germany Netherlands Table 25. Language code Code JA EN FR Language Japanese English French Code DE IT Language ...
  • HP 8550 | Service Manual - Page 73
    ... = ADF) Jam code First two digits indicate the type of jam (see table 29 on page 72) Last two digits indicate the sensor that detected the jam (table 30 on page 73) Location of pickup (see table 31 on page 73) Soft counter reading at the time of a jam Media size. G HHHHHH IIIII EN Service mode 71
  • HP 8550 | Service Manual - Page 74
    ... 2 digits 01 Last 2 digits 01 02 03 04 06 07 08 01 03 05 06 08 10 11 Jam type Pick-up delay jam 2 Intermediate transfer drum jam Face-down delivery outlet delay jam Pick-up delay jam 1 Fusing delivery delay jam Duplexing feeding assembly delay jam Reversing assembly delay jam Delivery long-length ...
  • HP 8550 | Service Manual - Page 75
    ... PS5 PS11 PS17 PS1801, PS1802 PS1903 PS24 PS26 PS5, PS11, PS17, or PS1903 PS1, PS, PS11, PS17, PS1801, PS1802, or PS1903 11 Table 31. G (pick-up position)... and the 2,000-sheet paper deck) Cassette 4 (supports the two 500-sheet paper decks) Multifeeder Duplexing unit (accessory) EN Service mode 73
  • HP 8550 | Service Manual - Page 76
    Copier, display mode, jam details (continued) Table 32. Pick-up jams Type of original Original extraction Sensor S1, S7 Description The sensor S7 does not detect the leading edge of an original 1500 msec after pick-up motor M1 has turned on and, in addition, the sensor S1 does not detect an ...
  • HP 8550 | Service Manual - Page 77
    ...a default size. 1. The original which has been picked up is not of a size supported by reduced image composition mode. 2. The size of the original which has been picked up...upon detection. 13 S3 S3 14 15 1To reset, remove the originals from the document tray, and open the ADF. EN Service mode 75
  • HP 8550 | Service Manual - Page 78
    ... 34. ERR screen legend Item AA EEEE FFFF G Description 1 through 20 (higher numbers indicate older errors) Error code "Exxx" (to decode error codes, see Chapter 7, "Troubleshooting") Detail code (if not available, "0000") Location (0 = copy module; 1 = ADF) 76 Chapter - 3 Operational overview EN
  • HP 8550 | Service Manual - Page 79
    ... Copier, I/O mode Level 1/Level 2 screen Table 35. Copier, I/O mode descriptions Item DC-CON R-CON FEEDER Description Input/output state of the CPU on the dc controller PCB Input/output state of the CPU on the reader controller PCB State of the CPU on the feeder controller PCB EN Service mode 77
  • HP 8550 | Service Manual - Page 80
    Address appears here. Each "x" in the sequence "xxxxxxxx" next to the address represents a digit, with bit 7 the first digit, bit 6 the second digit, and so on to bit 0, the last digit. Level 2 selection appears here (DC-CON, R-CON, or FEEDER) Figure 18. Copier, I/O mode Level 3 screen example ...
  • HP 8550 | Service Manual - Page 81
    ... no more than one sheet is set) Temperature and humidity sensor 00: normal temperature/normal humidity 01: high temperature/high humidity 10: normal temperature/low humidity 11: low temperature/low humidity P002 5 4 DUPPS 3 1 0 P003 1 0 LDECKS UPDECKS MPDFS TMPSNS HUMSNS EN Service mode 79
  • HP 8550 | Service Manual - Page 82
    Table 36. Copier, I/O mode Level 2 and Level 3 menus (continued) Level 2 R-CON (input/output Level 3 (address) P001 Bit 6 5 4 3 2 1 0 Item DSZ4 DSZ3 DSZ2 DSZ1 FLPWN FLERR CCIVCON E* FM4DEC CBCC KEYSW ACCON YON FLONOUT MMIRST LPHTON FM4ON BLON* ASTCNT CCIVCNT FL_TH SOFSWON Description SW7 of ...
  • HP 8550 | Service Manual - Page 83
    ...-up motor (M1) speed signal ("0" or "1" according to speed) ADF motor (M2) speed signal ("0" or "1" according to speed) Belt motor (M3) drive signal ("1" when on) Belt motor (M3) speed signal ("0" or "1" according to speed) P002 2 1 0 P003 P004 5 4 3 2 1 0 P006 7 6 4 3 2 EN Service mode 81
  • HP 8550 | Service Manual - Page 84
    Table 36. Copier, I/O mode Level 2 and Level 3 menus (continued) Level 2 FEEDER, continued Level 3 (address) P007 Bit 7 6 5 3 2 1 0 Item WGTSL CL BK ORGLED RSDRV SDIR EMPWM RFC UPCC1, CVRSW EJTS2 Description Paper holding plate solenoid (SL2) ("1" when on) Clutch (CL) drive ("1" when on) Brake ...
  • HP 8550 | Service Manual - Page 85
    ...-XY CCD IMG-REG DENS BLANK PASCAL COLOR HV-TR FEED-ADJ MISC Description Adjust... Adjust CCD- and shading-related items Correct color displacement Adjust developing density-related items Adjust... margins Execute auto gradation correction control Adjust color balance Adjust transfer charging bias output ...
  • HP 8550 | Service Manual - Page 86
    ... white plate Z signal data. Correct color displacement in sub-scanning direction dependent ... direction not dependent on G-B ratio. Correct color displacement in sub-scanning direction dependent ...: this number is specified on the CCD unit. Correct color displacement in sub-scanning direction dependent ...
  • HP 8550 | Service Manual - Page 87
    ...the color of reference. Adjusts the K pattern start position (2nd page, sub-scanning direction) when M is the color of reference. Adjusts Y density (toner deposit) for the printer unit to correct fusing faults. Adjusts M density (toner deposit) for...
  • HP 8550 | Service Manual - Page 88
    ... balance and the density of light areas of Y. Adjusts the color balance and the density of light areas ...balance and the density of light areas of C. Adjusts the color balance and the density of light areas ...COLOR Higher settings in ADJ categories make colors darker. Higher settings in OFST categories ...
  • HP 8550 | Service Manual - Page 89
    ... = 8 TR-N2H 0 to +15 Default = 8 TR-N2L 0 to +15 Default = 8 TR-N1N/L 0 to +15 Default = 8 TR-N2N/L 0 to +15 Default = 8 TR-TSM 0 to +15 Default = 8 0 to +15 Default = 8 0 to +15 Default = 8 0 to +15 Default = 8 0 to +15 Default = 8 TR-TSH TR-TSL TR-TSN/L TR-TLM EN Service mode 87
  • HP 8550 | Service Manual - Page 90
    Table 38. Copier, adjust mode Level 2 and Level 3 menus (continued) Level 2 item HV-TR (continued) Level 3 item TR-TLH Range 0 to +15 Default = 8 0 to +15 Default = 8 0 to +15 Default = 8 0 to +15 Default = 8 0 to +15 Default = 8 0 to +15 Default = 8 0 to +15 Default = 8 0 to +15 Default = 8 0 to...
  • HP 8550 | Service Manual - Page 91
    ... identify as black original; - values tend to identify as color original. When an image is being read for ACS, a large area of displaced color in a leading edge/ trailing edge/side width (main scanning ... increase the area. Fine, colored lines might be identified as part of a color original, but ...
  • HP 8550 | Service Manual - Page 92
    .... Record new settings on the service label on the copy module if you have changed the settings or replaced parts. Copier, adjust ... then record the values on the service label on the copy module. Copier, adjust mode, IMG-REG details (color image displacement) Higher settings move the pattern toward ...
  • HP 8550 | Service Manual - Page 93
    ...during image gradation correction control are compared to adjust the LUT gain for correction of each color. LUT-P-1, LUT-P-2, and LUT-P-3 settings: The density of Dhalf after auto...A, B, and C (which correspond to Test Prints 1, 2, and 3 used in auto gradation correction control). EN Service mode 91
  • HP 8550 | Service Manual - Page 94
    Copier, adjust mode, HV-TR and FEED-ADJ details Note The following information applies to both HV-TR (transfer charging bias output by condition) and FEED-ADJ (feeding system). To change a setting: 1 2 3 4 5 6 Enter a setting. Press OK. Select FUNCTION > MISC-P > DC-LOAD. Press OK. Turn off and ...
  • HP 8550 | Service Manual - Page 95
    ... the control panel. Check the various electric parts. Initialize RAM and resets jam/... module. Various adjustments and checks for the printer. The state of the copy module is indicated in the upper...: l l READY-copy module is ready for servicing/printing operations SERVICE-the copy module is executing...
  • HP 8550 | Service Manual - Page 96
    ...using cyan only. Press FILT-B, place a color original on the glass, and press OK....using cyan only. Press FILT-G, place a color original on the glass, and press OK... cyan only. Press FILT-R, place a color original on the glass, and press OK... LED-OFF KEY-CHK TOUCHCHK PART-CHK FAN-ON CLEAR ERR R-CON...
  • HP 8550 | Service Manual - Page 97
    ... "home" positions in sequence when you press OK: operation HP -> A is checked the first time you press OK operation ... when you press OK the second time operation HP -> C is checked when you press OK the third time operation HP -> D is checked when you press OK the fourth time Adjust the intensity of ...
  • HP 8550 | Service Manual - Page 98
    ...? M INTERRUPT 0-9, #, * CLEAR Key ID ACS Full Color Black Start Stop Save Power Screen indication ID ACS F-COLOR BLACK START STOP STAND BY Copier, run/check mode,... settings, complete the following steps: 1 Manually re-enter all 11 numbers that appear on the service label in service ...
  • HP 8550 | Service Manual - Page 99
    ... then load the data to the new ECO-2 PCB. 1 2 3 4 5 6 7 8 9 Start service mode. Select COPIER > FUNCTION > MISC-P > ... power. Replace the ECO-2 PCB. Turn on the power. Start service mode. Select COPIER > FUNCTION > MISC-P > DC-LOAD and then press OK. Exit service mode. Turn the power off and then back...
  • HP 8550 | Service Manual - Page 100
    ... related to the copier. Configure default settings related to user mode under 'BODY'. Set conditions for connection of an external controller (not available on the HP Color LaserJet 8550MFP). 98 Chapter - 3 Operational overview EN
  • HP 8550 | Service Manual - Page 101
    ..., but increases the first copy time by approximately 45 seconds. To set the fusing temperature to "off," see the HP Color LaserJet 8500/8550 Printer Family Service Manual. Enable/disable contrast potential/gradation correction data (0 = disable, 1 =...
  • HP 8550 | Service Manual - Page 102
    ... on the user screen differs depending on the method of maintenance (0 = service maintenance, 1 = user maintenance). Defaults: 1 in U.S.; 0 elsewhere. Indicate connection/... (0 = not connected, 1 = connected). Note: This setting is not available on the HP CLJ 8550MFP. You can disconnect the copy data ...
  • HP 8550 | Service Manual - Page 103
    ... 0 = disable (if brush-like lines occur), 1 = enable (if claw-like lines occur). Default is 1. Copy type 1st page Auto doublesided Manual double-sided H/H OFF Enable/disable the mechanism during this mode Enable/disable the mechanism during this mode N/N Enable/disable using this mode ON N/L ON ...
  • HP 8550 | Service Manual - Page 104
    ... remedy in H/H 2 = enable remedy in H/H and N/N Default = 0 To enable or disable the remedy: 1 2 3 4 5 Enter service mode. Enter the setting. Exit service mode. Turn off and then on the control panel power soft switch. Execute auto gradation correction in user ...
  • HP 8550 | Service Manual - Page 105
    ...counter details Guide to Terms l Functions: • C = copied pages • P = printed pages • S = scanned pages l Color... Total counter 1 Total counter 2 Total counter (full color 1) Total counter (full...) Total counter (small-size) Function C+P C+P C+P C+P C+P C+P C+P C+P C+P Color All All 4C 4C Mono...
  • HP 8550 | Service Manual - Page 106
    ...-and-white 2) Copy counter (full color, large-size) Copy counter (full ...-white, smallsize) Copy counter (full color, large-size, double-sided) Copy..., double-sided) Copy counter (mono color, small-size, double-sided) Copy... 2 Print counter (full color 1) Printer counter (full color 2) Print counter (mono...
  • HP 8550 | Service Manual - Page 107
    ... (black-and-white, smallsize) Print counter (full color, large-size, double-sided) Print counter (..., small-size, double-sided) Print counter (mono color, large size, double-sided) Print counter (...(full color, largesize) Copy + print counter (full color, smallsize) Copy + print counter (black-and-white...
  • HP 8550 | Service Manual - Page 108
    ...counter (small-size) Total counter (mono color, large-size) Total counter (mono ...white, smallsize) Copy scan counter (full color) Copy scan counter (black-and... 4) Copy scan counter (total 4) Function C C C C P P P P C+P C+P C+P C+P C C P P C+P C+P C+P C+P S S S S S S S S Color 4C + Mono 4C + Mono 4C...
  • HP 8550 | Service Manual - Page 109
    ... Setting 0 1 2 3 4 Black-and white copying disabled disabled disabled enabled enabled Black-and-white printing disabled disabled enabled disabled enabled Color printing disabled disabled enabled disabled enabled For example, if CONTROL is set to 421: l l l all printing and copying is permitted...
  • HP 8550 | Service Manual - Page 110
    Copier, test print mode (TEST) Figure 23. Copier, test print mode Level 1/Level 2 screen 108 Chapter - 3 Operational overview EN
  • HP 8550 | Service Manual - Page 111
    ...text/photo/map 4 = film photo 5 = printed photo 6 = text/photo 7 = black-and-white text Enable/...= disable, 1 = enable). Switch between full color and mono color for PG generation (0 = full color,...> COLOR (Y, M, C, or K). THRU DENS-Y DENS-M DENS-C DENS-K COLOR-Y COLOR-M COLOR-C COLOR-K F/M-SW EN 109
  • HP 8550 | Service Manual - Page 112
    ... 16 Test print Image from the CCD (normal copying) For R&D 256 colors 256 gradations 16 gradations Entire face in ...laser FF activation) For R&D YMCK 64 gradations BGR 64 gradations Full-color 16 gradations Full-color light area 16 gradations YMCK horizontal stripes (Laser A0 activation) 110 Chapter...
  • HP 8550 | Service Manual - Page 113
    Copier, counter mode Figure 24. Counter mode, Level 1/Level 2 screen Table 48. Copier counter menu descriptions Item TOTAL SCANNER PICK-UP FEEDER JAM Description Total counter Scan counter Pick-up counter ADF counter Jam counter Note All counters return to "00000000" after "99999999." EN 111
  • HP 8550 | Service Manual - Page 114
    ...-size total counter (copy + print + combination) Color large-size total counter (copy ...counter Small-size total copy counter Color large-size total copy counter ... Small-size total print counter Color large-size total print counter ... small-size total print counter 4-color total copy counter Y mono copy ...
  • HP 8550 | Service Manual - Page 115
    ... ADF. Indicates the total number of jams in the sorter (not available on HP CLJ 8550MFP). S-C42 MF L-MF S-MF DK3 L- ...Sheet Paper Deck, 2000-Sheet Paper Deck (not available on HP CLJ 8550MFP) : For the 2x500-Sheet Paper Deck (not available on HP CLJ 8550MFP) 3 : For the 1000-Sheet Paper Deck EN 113
  • HP 8550 | Service Manual - Page 116
    Feeder Figure 25. Note Feeder screen, example of a Level 3 item For FEEDER items, the Level 1 modes I/O, Test, and Counter are not used. Also, there are no Level 2 menus. 114 Chapter - 3 Operational overview EN
  • HP 8550 | Service Manual - Page 117
    ... the mode and stops automatically. Perform separation belt cleaning mode for top pick-up for the ADF. Note: The separation belt provides the "feed" function on the HP CLJ 8550MFP. 1. Select "UBLT-CLN' to highlight. 2. Moisten the center of a sheet of plain paper with isopropyl alcohol. 3. Place the ...
  • HP 8550 | Service Manual - Page 118
    116 Chapter - 3 Operational overview EN
  • HP 8550 | Service Manual - Page 119
    4 Adjustments and maintenance Chapter contents Overview ...119 MFP print engine adjustments...119 Parts unique to the HP LaserJet 8550MFP print engine ...119 Adjustments unique to the HP LaserJet 8550MFP print engine ...120 Copy module adjustments...121 End-...
  • HP 8550 | Service Manual - Page 120
    Cleaning ...164 Cleaning by an end-user ...164 Cleaning by service technicians ...164 Solvents ...164 Cleaning parts on the copy module ...165 Cleaning ADF parts ...167 Cleaning side HCI parts...173 Lubricating...174 118 Chapter 4 - Adjustments and maintenance EN
  • HP 8550 | Service Manual - Page 121
    ..., and the side HCI. Unique adjustments and parts for the HP LaserJet 8550MFP print engine (as compared to a standard HP LaserJet 8550 printer print engine) will also be addressed. MFP print engine adjustments Parts unique to the HP LaserJet 8550MFP ...
  • HP 8550 | Service Manual - Page 122
    ... HP LaserJet 8550MFP print engine To replace the dc controller PCB 1 2 3 Remove the dc controller PCB as shown in the HP Color LaserJet 8500/8550 Printer Family Service Manual. Install the new dc controller PCB. Reassemble the parts except for the printer ...
  • HP 8550 | Service Manual - Page 123
    ... these adjustments, see the Copy Module User Guide. l l Clean the glass, ADF belts and ... of the complaints is simply a limitation of a four-color process printer. Determine whether the image adjustment is... contrast and reduce granularity of photos. Adjust color balance. Increase or decrease relative ...
  • HP 8550 | Service Manual - Page 124
    Mechanical and electrical adjustments To adjust the non-image width and image margin on the copier The image margin and non-image width are correct if the following specifications are met (for copies made without reduction or enlargement): l l l leading edge: 5.0 ±2.0 mm left/right: 5.0 ±2.0 mm ...
  • HP 8550 | Service Manual - Page 125
    1 2 Start service mode on the copy module. If needed, adjust the leading edge margin registration (COPIER > ADJUST > ..., REGIST 2). This setting controls the timing of the registration clutch (CL1) engagement in the printer. REGIST adjusts the timing for when the registration clutch turns on for the ...
  • HP 8550 | Service Manual - Page 126
    ... adjust the copy module horizontal registration 1 2 3 4 Start service mode on the copy module. Enter '6' under COPIER > TEST > PG > TYPE in service mode to make a test print of a grid. Make ...ships with every unit and which installers are instructed to place on the stand behind the print engine....
  • HP 8550 | Service Manual - Page 127
    ... The copy module reproduces original images in full color by making fine adjustments to the amount of toner used. Incorrect adjustments and changes in... if the color exposure of copied images changes after a new color toner cartridge has been installed or other printer consumables have been replaced, ...
  • HP 8550 | Service Manual - Page 128
    ... to adjust the exposure of the copy. In instances when copy images are a little lighter or darker than the original, the copy exposure can be adjusted manually. This function adjusts the middle or normal exposure setting of the copy module touch panel display exposure scale. 1 2 3 4 Press . Select ...
  • HP 8550 | Service Manual - Page 129
    ...five minutes for the lamp to warm up. Start service mode on the copier. Select COPIER > FUNCTIONS ...controller PCB, or the firmware DIMM when various other parts have been replaced This procedure is also ...five minutes for the lamp to warm up. Start service mode on the copier. Select COPIER > FUNCTION ...
  • HP 8550 | Service Manual - Page 130
    .... The procedure can also be used to improve copy quality. Note This adjustment occurs automatically when the unit is powered on. 1 2 3 Select COPIER > FUNCTION > CCD > CCD-ADJ. Press OK. When END appears, the adjustment is complete. Exit service mode. 128 Chapter 4 - Adjustments and maintenance EN
  • HP 8550 | Service Manual - Page 131
    ...upgrading This section describes the adjustments necessary when the following parts have been replaced: l l l l l l l Reader controller ...cover" on page 334.) If possible, enter service mode and verify the 11 values ...92 0 1 0 8316 8782 9480 0 1 -1 Figure 30. Service label 3 Turn the copier off and...
  • HP 8550 | Service Manual - Page 132
    ... reader controller PCB and the old EEPROM). Enter service mode on the copier. 9 10 Select OPTION > USER.... 11 Initialize the RAM on the reader controller PCB in service mode (FUNCTION > CLEAR > R-CON). 12 Enter ... 19 Press OK. 20 When END appears, exit service mode. 21 Reinstall the lower front cover ...
  • HP 8550 | Service Manual - Page 133
    Replacing the firmware/localization DIMM 1 2 3 4 5 6 7 8 9 Enter service mode on the copier. Select COPIER > FUNCTION ... type in the values noted on the copy module service label. Select COPIER > FUNCTION > MISC...)" on page 375.) Turn on the copier. Enter service mode on the copier. Type in the new CCD ...
  • HP 8550 | Service Manual - Page 134
    ... front cover" on page 334.) Allow five minutes for the lamp to warm up. Enter service mode on the copier. Select COPIER > FUNCTION > MISC-R > LAMP-ADJ. Press OK....FUNCTION > CCD > CCD-ADJ. 10 Press OK. 11 When END appears, exit service mode. 12 Adjust auto gradation correction in user mode. (See "To ...
  • HP 8550 | Service Manual - Page 135
    ...lower front cover" on page 334.) Allow five minutes for the lamp to warm up. Enter service mode on the copier. Select COPIER > FUNCTION > MISC-R > USE-LAMP. Press OK.... > CCD > CCD-ADJ. 9 10 Press OK. 11 When END appears, exit service mode. 12 Adjust auto gradation correction in user mode. (See "To ...
  • HP 8550 | Service Manual - Page 136
    ... standard white plate cover" on page 363.) Enter service mode on the copier. Select COPIER > ADJUST > CCD... Press OK. To replace the AP-IP PCB 1 2 3 4 Enter service mode on the copier. Select COPIER > FUNCTION > CCD > CDD-ADJ. When END appears, exit service mode. Execute auto gradation correction in ...
  • HP 8550 | Service Manual - Page 137
    ... on Windows 2000) IEEE 1284-compliant port and B-type connector parallel cable To obtain and install the Service Support Tool 1 2 3 Download the Service Support Tool archive file. Run the self-extracting archive file. This program will extract two directories containing...
  • HP 8550 | Service Manual - Page 138
    ...Support Tool by clicking Start, then Programs, and then the Service Support Tool icon. The opening splash screen appears, ...The main menu allows two choices of operations: • Use Revision Control to add or delete firmware images to the Service Support Tool program. • Use Download/Upload to perform ...
  • HP 8550 | Service Manual - Page 139
    ... the parallel cable. Set the DIP switch SW1 to the LOAD position (left switch down). Turn on the computer. Start the Service Support Tool by clicking Start, then Programs, and then the Service Support Tool icon. Reconnect the copy module power cable. Turn on the rear ...
  • HP 8550 | Service Manual - Page 140
    ... the new firmware / language localization using the Service Support Tool 1 2 3 4 From the Service Support Tool main menu, click Continue... selected language. Pressing Start Write Operation will bring up a screen which tracks the status as the Service Support Tool program obtains more information from ...
  • HP 8550 | Service Manual - Page 141
    ... indicates that the download process ended successfully. 16 Click Return to Main Menu and exit the Service Support Tool. To turn the copy module off and return ... that the desired display language appears on the LCD. Start service mode and check the ROM version under COPIER > ...
  • HP 8550 | Service Manual - Page 142
    ADF adjustments Perform ADF adjustments if the ADF has been replaced, or as part of ADF troubleshooting. Mechanical and electrical adjustments are required for the ADF. CAUTION It is critical that these adjustments be performed in the order listed. Mechanical ...
  • HP 8550 | Service Manual - Page 143
    ... 5 2 6 2 7 2 3 2 1 Figure 32. Adjusting the ADF height 3 Loosen the lock nuts (callout 7) and turn the bolts of the left and right supports to raise and lower the ADF. 2 4 Note After adjustment, tighten the nuts (callout 7) to lock them. 4 5 Replace the ADF and recheck the height. Repeat steps 2...
  • HP 8550 | Service Manual - Page 144
    To correct the original skew 1 Remove the screw (callout 1), and detach the DADF controller PCB cover (callout 2). 2 2 1 Figure 33. DADF controller PCB cover 2 Shift bit 1 of the DIP switch (DSW1) on the DADF controller PCB to ON. Figure 34. DSW1 on the DADF controller PCB 3 Place an A3 or 11-...
  • HP 8550 | Service Manual - Page 145
    4 Press switch SW3 on the DADF controller PCB one time. The sheet is picked up and placed on the copyboard glass. Figure 35. SW3 DADF controller PCB 5 Open the ADF slowly, and measure the distance between the horizontal size plate and the sheet at any two points (l1 and l2) 150 mm apart along ...
  • HP 8550 | Service Manual - Page 146
    2 1 Figure 37. Rear view of the ADF 6 If the difference is not within 1 mm, loosen the nut (callout 1) at the rear of the right hinge unit (callout 2), and turn the adjusting screw (callout 3) to make adjustments. If ...l1 is greater than l2 l1 is less than l2 Then turn the adjusting screw ......
  • HP 8550 | Service Manual - Page 147
    ... in different positions compared to the positioning when copying from the glass. For this procedure, do not adjust the position of the original to match the positioning guides on the glass plate. 1 Shift bit 1 of the DIP switch (DSW1) on the DADF controller PCB to ON. Figure 39. DSW1 on the DADF ...
  • HP 8550 | Service Manual - Page 148
    4 Open the ADF slowly, and check to make sure that the distance l3 shown in the figure is as indicated. Note The l3 measurement for A3 paper should be 2.3±1 mm. The l3 measurement for 11-by-17 inch paper should be 11.1±1 mm A3 ± ± 11-by-17 inch Figure 40. Testing adjustment 5 If the ...
  • HP 8550 | Service Manual - Page 149
    9 Press SW3 again to advance another page to the copyboard glass. 10 Repeat step 4. If adjustment is necessary, repeat steps 5 through 8. 11 Return the DIP switch to the OFF position. To adjust the left edge stop position Be sure to perform "To correct the original skew" on page 142 and "To ...
  • HP 8550 | Service Manual - Page 150
    4 Open the ADF slowly, and measure the stop position l4; then, close the ADF. The distance l4 should be 11.0 ± 1 mm, and the left edge of the page should align with the indicator arrow on the horizontal size plate. Figure 43. Measuring the copy paper stop position 5 To adjust the original-...
  • HP 8550 | Service Manual - Page 151
    To adjust the sheet-to-sheet gap for two-page copy mode Be sure to perform "To correct the original skew" on page 142, "To adjust the distance from the horizontal size plate" on page 145, and "To adjust the left edge stop position" on page 147 before adjusting the sheet-to-sheet distance for ...
  • HP 8550 | Service Manual - Page 152
    4 Open the ADF slowly, and measure the distance l5 between the two sheets of copy paper. Then, close the ADF. Figure 45. Positioning paper 5 Use switches SW1 and SW2 on the DADF controller PCB to adjust the sheet-to-sheet distance. • Pressing SW1 increases the distance between sheets by 0.34 ...
  • HP 8550 | Service Manual - Page 153
    To adjust the ADF open/closed switch (MS1) 1 2 Remove the ADF body cover (upper). (See "Removing the body cover" on page 380.) Open and close the ADF and adjust the retaining plate (callout 1) so that the ADF switch MS1 (callout 2) turns on and off when the distance from the copyboard glass (...
  • HP 8550 | Service Manual - Page 154
    To adjust separation belt pressure Adjust the pressure of the separation belt under the following circumstances: l l if originals start to skew because of wear on the separation belt or the feeding roller if the separation belt or the feeding roller are replaced Prepare test strips for measuring ...
  • HP 8550 | Service Manual - Page 155
    3 Shift bits 5 and 6 of the DIP switch DSW1 on the DADF controller PCB to ON to select separation belt/feeding roller cleaning mode. Figure 50. DSW1 on DADF controller PCB 4 5 6 Press switch SW3 on the DADF controller PCB. Hook a spring-tension gauge through the tape-reinforced hole. Put the ...
  • HP 8550 | Service Manual - Page 156
    7 8 Open the upper cover of the ADF to end the measurement, and then Press switch SW3 on the DADF controller PCB one time. Table 52. Feeding power measurements Test strip 64 g/m2 80 g/m 2 Target feeding power (g) 300+30 330+30 9 If feeding power is insufficient, turn the adjusting screw ...
  • HP 8550 | Service Manual - Page 157
    Electrical adjustments Adjustments are required if the following parts are replaced on the ADF: l l l Document tray paper sensor (S1) Registration ... (VR1) Note Under the whole-unit replacement strategy, these parts will not be replaced in the field. To adjust the document tray paper sensor (S1) ...
  • HP 8550 | Service Manual - Page 158
    3 I Without placing paper on the document tray, press switch SW3 on the DADF controller PCB. LED 1 and 2 will turn on. Figure 54. LED 1 and 2 on DADF controller PCB 4 5 Press switch SW3 again one time. The LEDs turn off and the adjustment is complete. Return the DIP switch to the OFF position. ...
  • HP 8550 | Service Manual - Page 159
    ... portrait orientation (long edge leading) in the document tray and adjust the side guides to the width of the page. Press switch SW3 on the DADF controller ... orientation (short edge leading) in the document tray and adjust the side guides to the width of the page. Push switch SW3 again one time and ...
  • HP 8550 | Service Manual - Page 160
    Replacing the DADF controller PCB CAUTION Use care when performing this procedure. The setting on the DADF controller PCB can be configured only one time. If set incorrectly, damage may result in the ADF and DADF controller PCB. 1 Set the paper setting: e Remove the PCB cover of the ADF. f Turn ...
  • HP 8550 | Service Manual - Page 161
    Side HCI adjustments There are three adjustments for the side HCI: l l l Gap between the printer and the side HCI Base plate position Paper-size change (A4 or letter) Gap between the printer and the side HCI Note Improper adjustment of this gap can cause misfeeds....
  • HP 8550 | Service Manual - Page 162
    ... placed too far to the top of the page, move the plate toward the rear of the printer. If the printout is placed too far to the bottom of the page, move the plate toward the front of the printer. When adjustment is complete, tighten the two securing screws. Note You might have ...
  • HP 8550 | Service Manual - Page 163
    ... change (A4 or letter) 1 Loosen the two white paper-guide fixing screws. Figure 58. Paper guide fixing screws 2 Lift the paper guides out of their slots and place them into the ... for LTR or A4, as labeled. Figure 59. Paper guides 3 Replace the fixing screws. EN Side HCI adjustments 161...
  • HP 8550 | Service Manual - Page 164
    4 Insert the plastic paper-size tab so that the notation for the correct size is displayed (LTR or A4). Figure 60. Note Paper size card If the side HCI fails to register letter, or incorrectly reports A4 instead of letter, reinsert the plastic paper-size tab to make sure that the tab is ...
  • HP 8550 | Service Manual - Page 165
    ...and side HCI do not contain parts that must be replaced after a certain number ... only and do not indicate a point at which the part must be replaced. Replace ... only. Table 53. Periodically replaced parts Part name Copy module Lamp ...HCI Feed roller and separation roller Part number FH7-3336-000CN FH6-...
  • HP 8550 | Service Manual - Page 166
    ... ADF. Execute ADF cleaning( FEEDER CLEANING). , ADJUSTMENTS/CLEANING, l Note For information on cleaning the printer, see the printer service manual. Cleaning by service technicians Service technicians should perform cleaning during a service visit, not periodically....
  • HP 8550 | Service Manual - Page 167
    Cleaning parts on the copy module To clean the copyboard glass and cover 1 Wipe the copyboard glass and cover with a cloth moistened with water or solution of mild detergent; then, wipe them dry. Figure 61. Copyboard glass 2 Wipe the inside surface of the copyboard cover with a cloth moistened ...
  • HP 8550 | Service Manual - Page 168
    .... Keep the CCD free from dust. For a list of periodically replaced parts of and consumables/durables for the printer unit, see the HP Color LaserJet 8500/8550 Printer Family Service Manual. 166 Chapter 4 - Adjustments and maintenance EN
  • HP 8550 | Service Manual - Page 169
    Cleaning ADF parts l l l l Inspect and blow paper dust out of timing sensors. Clean ..., lintfree, soft cloth (right). To clean the separation guide, use alcohol, or, in absence of alcohol, use a ... in paper-feed direction. See "To clean the separation guide" on page 173. Clean the vertical size plate ...
  • HP 8550 | Service Manual - Page 170
    To clean the belt assembly 1 Move the feeding belt in the direction of the arrow as you wipe it with a water-dampened cloth. Figure 63. Belt assembly 2 Moisten the center of a sheet of copy paper with alcohol and place the paper on the document tray; then, shift bit 6 of the DIP switch (SW1) on ...
  • HP 8550 | Service Manual - Page 171
    To clean the sensors The ADF's feeding path is equipped with two transmission-type sensors (original sensor S1, registration sensor S3) and three photointerrupers (pick-up sensor S7, delivery sensor S6, reversal sensor S8). The light-receiving face of a transmission-type sensor tends to collect ...
  • HP 8550 | Service Manual - Page 172
    ... 2 1 2 Figure 67. Reflecting face sensor To clean the registration sensor (S3) 1 2 Remove the separation belt unit. Remove the four screws (callout 1), and detach the separation guide plate (callout 2). 2 1 2 2 1 Figure 68. Registration sensor 170 Chapter 4 - Adjustments and maintenance EN
  • HP 8550 | Service Manual - Page 173
    3 Remove the two screws (callout 3), and detach the inside guide plate (callout 4). 2 4 2 3 Figure 69. Guide plate 4 Clean the registration sensor S3 (callout 5) mounted on the inside of the plate (callout 4). 2 3 2 4 2 5 Figure 70. Registration sensor EN Cleaning 171
  • HP 8550 | Service Manual - Page 174
    To clean the registration sensor LED3 1 Remove the screw (callout 1), and detach the registration sensor LED3 cover (callout 2) of the reversing roller unit (callout 3). 2 1 2 2 3 Figure 71. Registration sensor LED3 cover 2 Clean the light-emitting face of the registration sensor LED3 (callout ...
  • HP 8550 | Service Manual - Page 175
    ...two front separation flappers. Clean all 12 areas of the pre-separation guide with alcohol. Make cleaning strokes in the paper-feed direction. Figure 73. Separation guide Cleaning side HCI parts Clean the following items periodically using a water-dampened, lintfree, soft cloth:...
  • HP 8550 | Service Manual - Page 176
    Lubricating The HP Color LaserJet 8550MFP does not have any parts that require periodic lubrication. Apply lubricant only if contamination has necessitated cleaning, or if lubricated parts have been replaced. CAUTION When applying lubricant, take care that other parts are not ...
  • HP 8550 | Service Manual - Page 177
    ... the scanning lamp ...193 Identifying the size of originals when copying from the glass ...197 Copy module image processing system...200 CCD ...201 CCD driver ...202 AP-IP (analog image processing) PCB ...203 Digital image processing ...206 Control panel ...232 Fan ...234 Power supply ...235 EN ...
  • HP 8550 | Service Manual - Page 178
    ADF ...244 ADF electrical circuitry ...244 Communication with the copy module ...245 Inputs and outputs to the DADF controller PCB ...246 Basic operation ...249 Functional overview ...250 Picking up originals ...256 Reversal operation ...261 Reduced page composition ...263 Delivery operation ...266...
  • HP 8550 | Service Manual - Page 179
    ..., follow these steps: 1 2 Switch the control panel soft switch to off. Wait at least 30 minutes while the HP Color LaserJet 8550MFP cools down. Failure to allow at least 30 minutes for cooling can damage toner cartridges. Switch the rear power switch...
  • HP 8550 | Service Manual - Page 180
    Copy module Functional construction The copy module may is divided into two functional blocks: control system and exposure system. Copy module Figure 75. Copy module 178 Chapter 5 - Theory of operation EN
  • HP 8550 | Service Manual - Page 181
    Outline of electrical circuitry The main electrical mechanisms of the copy module are controlled by the CPU on the reader controller PCB. The reader controller PCB is equipped with a lithium battery for backing up important data. The control panel is equipped with its own CPU for control of keys, ...
  • HP 8550 | Service Manual - Page 182
    Inputs to and outputs from the major PCBs See "Controlling the scanning lamp" on page 193. See "Controlling the scanning lamp" on page 193. See "Scanner motor" on page 191. See "Upgrading and localizing the copy module firmware" on page 135. Figure 77. Inputs to and outputs from the reader ...
  • HP 8550 | Service Manual - Page 183
    See "Originalsize sensors" on page 198. See "Control panel" on page 232. Figure 78. Inputs and outputs from the reader controller PCB (2 of 3) EN Copy module 181
  • HP 8550 | Service Manual - Page 184
    ADF Figure 79. Inputs and outputs from the reader controller PCB (3 of 3) 182 Chapter 5 - Theory of operation EN
  • HP 8550 | Service Manual - Page 185
    Basic sequence of operations Figure 80. Basic sequence of operations at power-on EN Copy module 183
  • HP 8550 | Service Manual - Page 186
    ... reaches 165° C. Purpose To heat the fusing roller and to put the printer into standby state. Remarks During this period, the printer checks for residual paper and the presence/absence of the toner cartridge, and executes correction for stable reproduction of images. ...
  • HP 8550 | Service Manual - Page 187
    Sequence of operations during copying Figure 81. A4- and letter-size, 2 copies, 4-color, Direct, and cassette 1 sequence of operations (1 of 2) Copy module 185 EN
  • HP 8550 | Service Manual - Page 188
    Figure 82. A4- and letter-size, 2 copies, 4-color, Direct, and cassette 1 sequence of operations (2 of 2) 186 Chapter 5 - Theory of operation EN
  • HP 8550 | Service Manual - Page 189
    ... START key is pressed until the point of rotation of the intermediate transfer drum reaches the leading edge of the first color. From when control rotation ends until all toner has been transferred to the copy paper. From when COPY ends until the ...
  • HP 8550 | Service Manual - Page 190
    Copy module exposure system The exposure system includes functions used to expose the original and direct the reflected optical image to the CCD. Figure 83 is a cross-section of the exposure system, while figure 84 is a diagram of the mechanics involved. Figure 83. Cross-section of exposure ...
  • HP 8550 | Service Manual - Page 191
    Basic sequence of operations Figure 85. A4- and letter-size, 2 copies, 4-color, Direct, cassette 1 sequence of operations l l l l INTR-initial rotation ODETCT-original detection and shading correction LSTR-last rotation; approximately equal to secondary transfer end to paper discharge DSRDY-...
  • HP 8550 | Service Manual - Page 192
    ... following timing: l l l l When the power is turned on When COPY START is pressed When all originals are read While the CCD is being adjusted in service mode The home position sensor does not turn on during continuous copying; if the sensor does turn on, scanning stops immediately. Figure 86 shows...
  • HP 8550 | Service Manual - Page 193
    Scanner motor Figure 87 shows the circuit used to control the scanner motor. The circuit has the following functions: l l Controls the direction of rotation of the scanner motor Controls the speed of rotation of the scanner motor The scanner motor changes its direction of rotation to move the ...
  • HP 8550 | Service Manual - Page 194
    ...STEP_ANGLE through STEP_ANGLE3 signals to the scanner motor driver PCB to suit the scanning mode, distance,...motor control IC (Q301) on the scanner motor driver PCB generates motor drive pulses ...ratio The reproduction ratio in main scanning direction (drum axial direction) is changed by skipping image ...
  • HP 8550 | Service Manual - Page 195
    Controlling the scanning lamp The scanning lamp in the copy module is a fluorescent lamp. The lamp is turned on and off by the inverter PCB according to the reader controller PCB. The reader controller PCB controls the following functions: l l l l l l Scanning lamp preheating mechanism Power to ...
  • HP 8550 | Service Manual - Page 196
    Controlling the pre-heating mechanism of the scanning lamp To reduce the time required for the scanning lamp to reach its optimum intensity after COPY START is pressed, the filament of the scanning lamp is supplied with power. This mechanism is called "preheating," and it may be standby pre-heating...
  • HP 8550 | Service Manual - Page 197
    ..., during which time the scanning lamp heater is controlled to 70° C. The scanning lamp heater is not turned on unless the scanning lamp is turned on as part of preparatory activation. If the temperature is 40° C or more at power-on, the copy module will assume that the power has been turned on ...
  • HP 8550 | Service Manual - Page 198
    ... conditions is detected, the copy module assumes the end of the scanning lamp, and indicates a message under COPIER > DISPLAY > MISC > FL-LIFE in service mode. To replace the scanning lamp, see "Removing the scanning lamp and scanning lamp heater" on page 357. Detecting errors Table 58 shows the ...
  • HP 8550 | Service Manual - Page 199
    Identifying the size of originals when copying from the glass The copy module identifies the size of an original in reference to an original placed on the copyboard glass, and turns on the following functions based on the identified size: l l Automatic paper selection Automatic ratio selection ...
  • HP 8550 | Service Manual - Page 200
    ...a flag blocks photointerrupter PS102 (callout 4) and it turns on. For 15 seconds after PS 102 turns on, or until START is pressed, the output level of each ... Book original (thickness prevents changes in the sensor level) c Copyboard cover open (PS 102 is off) Note In each case above, the copy module ...
  • HP 8550 | Service Manual - Page 201
    Identifying the size of originals The reader controller PCB identifies the size of an original based on signals indicating the presence or absence of an original. l Unchanged: the output of the sensor is read about every 100 ms after the copyboard cover opened/closed sensor turns on. The notation ...
  • HP 8550 | Service Manual - Page 202
    ...system into electrical signals, which are then sent to the laser exposure system of the printer. The image processing system also performs corrections and various image processing... electrical images. The image processing system consists of a CCD, CCD driver PCB, and AP-IP PCB. Copy module Figure 92...
  • HP 8550 | Service Manual - Page 203
    CCD The CCD (charge-coupled device) consists of a 3-line CCD composed of about 7,500 photocells. Each CCD line is covered with a blue, green, or red filter (callout 1) and consists of a transfer block (callout 2) and an output block. The output of the odd-numbered photocells (callout 3) and the ...
  • HP 8550 | Service Manual - Page 204
    CCD driver The image signals generated by the CCD are sent through a buffer (low-impedance circuit) for reduction of impedance and then to the AP-IP PCB. Figure 94. CCD circuit 202 Chapter 5 - Theory of operation EN
  • HP 8550 | Service Manual - Page 205
    ...SH1 through SH4) for extracting signal components. Thereafter, BGR signal levels are matched according to the BGR gain and offset signals for correction of photo conversion efficiencies (of the B, G, and R CCD lines); then, the results are synthesized into B, G, and R image signals according to the ...
  • HP 8550 | Service Manual - Page 206
    ABC (auto background control) circuit AE Mode The copy module's AE mode (in black-and-white text mode) may be set to either of the following: l l Priority on speed (factory default) Priority on image quality In general, "priority on speed" is best for mostly text originals, and turns out first ...
  • HP 8550 | Service Manual - Page 207
    ... 96 above, the range A of a white background original is varied (as in the case of the range B of a colored background original) to "white out" a colored background. In addition, the ABC circuit is designed to return image signals resulting from A/D conversion to the ABC circuit for ...
  • HP 8550 | Service Manual - Page 208
    ... panel. At the end of data conversion, the image data is sent to the printer unit in the form of 8-bit image signals. Table 61. PCB ... AP-IP PCB Functions Shading correction, 3-line position matching, sensor color correction, background cancellation, logarithmic correction, text identification, pre-...
  • HP 8550 | Service Manual - Page 209
    Figure 97. Digital image processing Gm MJ KRO KMJ L Ca Cb G Image signal for text detection Text detection signal Black pixel signal Black text identification signaL Luminous component signal Color component signal Color component signal EN Copy module 207
  • HP 8550 | Service Manual - Page 210
    ... each time START is pressed. If the standard white plate is ever replaced, the value printed under its bar code (callout 2) must be entered in service mode. The shading correction circuit compares the measurement data gathered by the CCD from the standard white plate and the target value from the ...
  • HP 8550 | Service Manual - Page 211
    ... correction Characteristics before correction Standard white plate Original density Note The color balance of light areas may be adjusted in service mode (ADJUST > COLOR > OFST-Y/M/C/K). Shading correction tends to be stronger over areas where scratches or dirt exist on ...
  • HP 8550 | Service Manual - Page 212
    CCD 3-line position matching The CCD consists of three CCD arrays, each covered with an R, G, or B filter. The line image from any CCD at any point in time, therefore, is subject to a discrepancy of about 0.33 mm (12-line equivalent) in reference to the copyboard glass. To correct these ...
  • HP 8550 | Service Manual - Page 213
    ...detect the edge component; it then identifies whether the pixel in question is part of the edge of a character or not based on the size of the edge ... and the distribution of edge components. When the copy module identifies it as part of an edge, it generates the MJ signal (text detection signal). The...
  • HP 8550 | Service Manual - Page 214
    ... lets through light of wavelengths outside a specific range, requiring color correction. In the case of the G filter, the filter lets through light of ... of wavelengths falling within b (figure 102). 2 2 1 Figure 102. Sensor color correction measurement The following computations are made so as to ...
  • HP 8550 | Service Manual - Page 215
    ... reflected by an original, the CCD also reads the color data of the surface (background) of the paper. To correct ... adjustment; see the copy module user guide) provides two modes, each with a different... is corrected to 255 to remove the specified background color. In "anti-see-through mode" or "second...
  • HP 8550 | Service Manual - Page 216
    ... in the R/G/B->L/Ca/Cb conversion block, the RGB image signal is converted to chromatic spaces of L (light area component) and Ca/Cb (color component). L=(R+2G+B)/4 Ca=(R-G)/2 Cb=(R+G-2B)/4 Using L/Ca/Cb, the copy module performs spatial filter processing and chromatic identification. After spatial ...
  • HP 8550 | Service Manual - Page 217
    Figure 104. Input level Figure 105. Weak and strong sharpness The copy module also performs chromatic identification (used for ACS, black text identification) based on the L (luminous component) signal and the Ca/Cb (chromatic component) signal. After chromatic identification, the copy module ...
  • HP 8550 | Service Manual - Page 218
    Logarithmic correction and BGR->YMC conversion A Logarithmic Correction The output of the CCD has linear characteristics in relation to the light reflected by an original. However, the density perceived when looking at an original does not necessarily have linear characteristics. Figure 106 shows ...
  • HP 8550 | Service Manual - Page 219
    ... of the fact that BGR chromatic components are in a complementary relationship to YMC toners (reflected light). Table 62. BGR->YMC conversion Toner Y B Chromatic light Absorbs M Reflects C Reflects G Reflects Absorbs Reflects R Reflects Reflects Absorbs Figure 108. ...
  • HP 8550 | Service Manual - Page 220
    The level of transmission of each filter (B, G, R) of the CCD and the density (Y, M, C) of the original are in a complementary relationship; level conversion is performed as in figure 109 to generate the Y, M, and C signals. Figure 109. Note BGR to YMC conversion _ _ _ Y = B, M = G, C = R 218 ...
  • HP 8550 | Service Manual - Page 221
    UCR (under color removal) processing In theory, when equal parts of Y, M, and C toners are mixed, black will be ... light). However, since no toner possesses pure chromatic absorption characteristics, mixing the three colors (as in YMC conversion) in equal parts will not produce a pure black. In this ...
  • HP 8550 | Service Manual - Page 222
    ... size of the component that has been replaced is referred to as "UCR amount," and it is 100% in the case of figure 111. With URC at 100%, Bk toner would be used on the entire image, causing shading in light areas. The UCR amount, therefore, is increased or decreased in relation to the text signal, ...
  • HP 8550 | Service Manual - Page 223
    Output masking A color image is reproduced using color toners since the Y toner absorbs only B components, the M ... the result to have a reddish tinge, requiring removal (masking) of the Y component from the Y toner in advance. In this block, the excess component of each toner is corrected by means of...
  • HP 8550 | Service Manual - Page 224
    Enlargement/reduction and image processing 1 Enlargement/reduction a Horizontal reproduction ratio (main scanning direction) Data units may be skipped when they are written into the memory (reduction) or read multiple times from the memory (enlargement). b Vertical reproduction ratio (sub-scanning ...
  • HP 8550 | Service Manual - Page 225
    2 Enlargement Correction In enlargement, the image data is corrected so that the difference in density between pixels will not vary excessively. Figure 114 shows the image data of an original, image data in enlargement, and image data after enlargement correction. Figure 114. Enlargement/...
  • HP 8550 | Service Manual - Page 226
    3 Shift The following diagrams provide an outline of the principles of how an image is shifted in main and sub scanning directions. Figure 115. Image shifts Figure 116. Shift in main and sub-scanning directions 224 Chapter 5 - Theory of operation EN
  • HP 8550 | Service Manual - Page 227
    The position of an original may be shifted as follows by combining a shift in main scanning direction and a shift in sub-scanning direction: • Center shift The copy module computes the coordinates (Xm, Ym) of a corner which make the top/bottom and left/right margins of the copy equal, based on ...
  • HP 8550 | Service Manual - Page 228
    4 Mirror image When reading data for a single scan from the RAM, reading is started in reverse direction to create a mirror image in relation to main scanning direction. Main scanning direction Sub scanning direction Figure 118. Mirror image Figure 119. Mirror image ...
  • HP 8550 | Service Manual - Page 229
    5 Image repeat When reading data for a single scan from the RAM, an S address (read start address) and an E address (read end address) are specified. Then, reading is started with the S address and, upon reaching the E address, reading is continued while returning to the S address. A repeat image ...
  • HP 8550 | Service Manual - Page 230
    6 Slant When reading data for a single scan from the RAM, the starting address (S address) is shifted by an n number of lines for slant processing. Main scanning direction Sub scanning direction Figure 122. Slant Address 12345678...nnn -1 -2 Figure 123. Slant principle 228...
  • HP 8550 | Service Manual - Page 231
    ...: a Setting of the Copy Density key on the control panel b Setting of color balance (control panel) c Setting of color balance (service mode) (COPIER > ADJUST > COLOR > ADJ-Y/M/C/K) d Adjusting the light area density and color balance in service mode COPIER > ADJUST > COLOR > ...
  • HP 8550 | Service Manual - Page 232
    Framing and blanking For framing and blanking, as many as four areas and as many as 10 points may be selected. l Framing The signals representing areas outside the selected areas of an original are forced to represent white. Figure 126. Framing l Blanking As opposed to framing, the signals ...
  • HP 8550 | Service Manual - Page 233
    Anti-counterfeit processing The copy module is equipped with the following two functions designed to prevent counterfeiting of bank notes or securities certificates. l Tracking A unique ID number (stored in the copy module memory) is printed on all copies, invisible to the eye, so that any ...
  • HP 8550 | Service Manual - Page 234
    ...the reader controller PCB. LCD processing The CPU on the reader controller PCB provides the control panel CPU PCB with data (display data) as instructed by the program. The data is moved through the control panel CPU PCB to the LCD panel. LCD contrast adjustment The control panel is equipped with ...
  • HP 8550 | Service Manual - Page 235
    Figure 128. Control panel EN Copy module 233
  • HP 8550 | Service Manual - Page 236
    Fan The copy module is equipped with a single fan to cool the copy module. Figure 129 shows the location of the fan and the air movement when the fan is turned on. Table 64 shows its function, filter, direction, and associated error code. Figure 129. Copy module fan Table 64. Copy module fan ...
  • HP 8550 | Service Manual - Page 237
    ... turn on the power cut relay, thereby supplying the printer unit with AC power. The copy module main... mode l l Control panel power soft switch ON ON Fuser assembly OFF Variable temperature control ON...save mode-In auto power save mode, the fuser assembly remains on; however, the temperature control ...
  • HP 8550 | Service Manual - Page 238
    module rear power switch, leaving the copy module alone for approximately three minutes, and turning on the copy module rear power switch/control panel power soft switch. Figure 131. Power 236 Chapter 5 - Theory of operation EN
  • HP 8550 | Service Manual - Page 239
    ... of the printer only to the outlet of the copy module. Connecting the printer power cord directly to an external outlet is acceptable when troubleshooting. Do not disconnect or ... the secondary side of the power supply. (not available for LJ 8550 MFP) ADF Figure 132. Copy module power ...
  • HP 8550 | Service Manual - Page 240
    ...) in response to the remote signal from the reader controller PCB. As in the case of the copy module main power supply PCB and the printer unit low-voltage power supply PCB, the accessories power supply PCB is equipped with an overcurrent protective function and an overvoltage protective function to...
  • HP 8550 | Service Manual - Page 241
    Table 66. Copy module main power supply Signal FU1501, FU1505, FU1514 FU1506, FU1512, FU1518 FU1516, FU1517 FU1502, FU1503, FU1504, FU1519 FU1507 FU1515 FU1511, FU1513 FU1509 FU1508 F1 F12, F18 F19, F20, F24, F28 F29, F30 F11, F13, F14, F15, F17 F27 F16 F21, F23 F25 F26 Rating 1 A, 60 V 2 A, 60 V ...
  • HP 8550 | Service Manual - Page 242
    Reader unit main power supply PCB Reader controller PCB Figure 133. Copy module general circuit diagram (1 of 2) 240 Chapter 5 - Theory of operation EN
  • HP 8550 | Service Manual - Page 243
    Reader unit main power supply PCB Reader controller PCB EN Copy module 241
  • HP 8550 | Service Manual - Page 244
    Figure 134. Copy module general circuit diagram (2 of 2) 242 Chapter 5 - Theory of operation EN
  • HP 8550 | Service Manual - Page 245
    EN Copy module 243
  • HP 8550 | Service Manual - Page 246
    ADF ADF electrical circuitry The ADF's electrical mechanisms are controlled by the DADF controller PCB. A microprocessor (CPU) is used on the DADF controller PCB, and the microprocessor reads the input signals from the sensors and the copy module and generates signals used to drive dc loads (motors...
  • HP 8550 | Service Manual - Page 247
    Communication with the copy module The operation modes selected on the copy module are communicated to the ADF in an IPC communication method. Likewise, the operation states of the ADF are communicated to the copy module in an IPC communication. If an error occurs in the IPC communication, the self...
  • HP 8550 | Service Manual - Page 248
    Inputs and outputs to the DADF controller PCB Figure 137. Inputs to the DADF controller PCB (1 of 2) 246 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 249
    Figure 138. Inputs to the DADF controller PCB (2 of 2) EN ADF 247
  • HP 8550 | Service Manual - Page 250
    Figure 139. Outputs to the DADF controller PCB 248 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 251
    Basic operation The ADF uses four motors and one clutch to pick up, feed, and deliver originals. The pick-up motor (M1) serves to pick up originals. The ADF motor (M2) serves to pick up originals and reverse and deliver originals. The belt motor (M3) moves and stops originals to and on the ...
  • HP 8550 | Service Manual - Page 252
    Functional overview The ADF performs the following five operations: l l l l l Top pick-up mode original-feeding Single-sided original to double-sided copy Double-sided original to single-sided copy Double-sided original to double-sided copy using the standard duplexing unit Two small-size ...
  • HP 8550 | Service Manual - Page 253
    Top pick-up feeding The ADF picks up the originals on the document tray from the top (first page of the stack), and places them on the copyboard glass. Each time an original has been read, the ADF moves the original from the copyboard glass to the original delivery tray. Figure 141. Top pick-up ...
  • HP 8550 | Service Manual - Page 254
    Double-sided original mode The ADF feeds double-sided originals in two ways depending on the specified printer output tray. l If the output tray is the left, or face up, output tray (default when copying double-sided originals, the procedure is as follows: 1 Pick up the original. 2 Copy the first ...
  • HP 8550 | Service Manual - Page 255
    Figure 142. Face-up (left) output tray EN ADF 253
  • HP 8550 | Service Manual - Page 256
    Figure 143. Face-down (top) output tray 254 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 257
    Reduced page composition mode When reducing and copying two originals in page composition mode, the ADF automatically picks up two originals and places them on the copyboard glass side by side. Table 68 shows the sizes of originals that may be used in the ADF. Table 68. Page composition sizes ...
  • HP 8550 | Service Manual - Page 258
    ..., the arm on the pick-up roller shaft transmits its drive to the original guide and the switching arm. In response, the original guide moves downward. Then, the rear and the front of the separation belt operating in connection with the switching arm move upward to ...
  • HP 8550 | Service Manual - Page 259
    Pick-up operation When top pick-up mode is executed with originals on the document tray, the following will take place: 1 Pick-up separation The paper stop plate is brought down, and the paper retaining plate is moved down to the stack of originals; then, the first page of the stack is picked up. ...
  • HP 8550 | Service Manual - Page 260
    2 Arching The original is butted against the registration roller so that it arches. This ensures that the original will be fed without rotational skew. Figure 147. Feeding sequence 3 Feeding The feeding belt, registration roller, and separation belt are rotated to move the original to the ...
  • HP 8550 | Service Manual - Page 261
    4 Picking up the second original When the original reaches the correct position on the copyboard glass, the copy module scanner starts to move forward. At the same time, the second original is picked up (if A4- or letter-size). In the case of a large-size original (A3-size or 11-by-17 inch), the ...
  • HP 8550 | Service Manual - Page 262
    Sequence of operations (A4, two originals, top pickup mode) Figure 150. Sequence of operations (A4, 2 originals, top pick-up mode) 260 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 263
    Reversal operation Reversal may be either from the first side to the second side, or from the second side to the first side. (Since the same mechanism is involved, the discussions herein will be on reversal from the first side to the second side.) l Picking up for the first side An original is ...
  • HP 8550 | Service Manual - Page 264
    Sequence of operations (reversal) Figure 153. Sequence of operations (reversal) 262 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 265
    Reduced page composition In top pick-up mode, the originals are picked up starting with the top sheet, not requiring reordering of the originals. 1 Picking up the first original Figure 154. Placement of first original The first original is picked up and stopped on the copyboard glass. For details...
  • HP 8550 | Service Manual - Page 266
    3 Feeding the first and second originals simultaneously Figure 156. Movement of first and second originals The clutch (CL) is turned on to eliminate the difference in speed between the delivery/reversing roller an the feeding belt, and the two originals are fed simultaneously. 4 Delivering the...
  • HP 8550 | Service Manual - Page 267
    Sequence of Operations (reduced page composition) Figure 158. Sequence of operations (reduced page composition; top pickup) EN ADF 265
  • HP 8550 | Service Manual - Page 268
    Delivery operation Figure 159. Delivery path The ADF delivers originals to the document delivery tray. Figure 160. Feeding the first original The ADF delivers the original on the copyboard tray as follows: 1 Feeding the first original The feeding belt is rotated counterclockwise to feed the ...
  • HP 8550 | Service Manual - Page 269
    2 Delivering the first original and picking up the second original Figure 161. Delivering the first original and picking up the second original The clutch (CL) is turned on to eliminate the difference in speed between the delivery/reversing roller and the feeding belt; the first original is ...
  • HP 8550 | Service Manual - Page 270
    Sequence of operations (small size, pick-up and delivery) Figure 162. Sequence of operations (small size, pick-up and delivery) 268 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 271
    Detecting originals The ADF has the following types of document detection: l l l l The presence or absence of an original on the document tray The size of originals place on the document tray The number of originals that have been copied The trailing edge of the last original Detecting the ...
  • HP 8550 | Service Manual - Page 272
    2 1 2 2 3 Figure 164. Document tray 1 2 3 Original-set indicator Original Document tray 270 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 273
    Detecting the size of an original The ADF detects the size of an original in relation to the vertical (feeding) and horizontal directions of the original, to provide correct original size detection. Detecting in vertical (feeding) direction Detection in the vertical direction is made by the ...
  • HP 8550 | Service Manual - Page 274
    ... made by the original-width detecting volume (VR) on the document tray. The original-width detecting volume operates in conjunction with the side guides (callout 1) on the document tray. As its resistance varies, the changes are detected by the DADF controller PCB, which converts them into length in...
  • HP 8550 | Service Manual - Page 275
    Tables 69 and 70 show the default sizes that are identified: Table 69. Europe/Asia (A4) Vertical 257 mm 148.2 mm 330 mm 330 mm 182 mm 364 mm 381 mm 210 mm 420 mm Horizontal 177 to 187 mm 205 to 215 mm 205 to 215 mm 205 to 215 mm 252 to 262 mm 252 to 262 mm 274 to 284 mm 292 to 302 mm 292 to 302 mm...
  • HP 8550 | Service Manual - Page 276
    ... on the document tray is still resting on an original, the ADF communicates to the printer that the third and subsequent originals are present, and the printer ... lever on the document tray has dropped, the ADF communicates to the printer that there is not third or subsequent originals (RSS signal) so...
  • HP 8550 | Service Manual - Page 277
    Controlling the pick-up motor The ADF motor is a dc motor. The microprocessor (Q1) on the DADF controller PCB sends the pick-up motor drive signal (SMON), pick-up motor rotation direction signal (SDIR), and the pick-up motor rotation speed control signal (SMPWM) to the drive circuit. In response, ...
  • HP 8550 | Service Manual - Page 278
    Table 71 shows the relationship between the pick-up motor drive signal (SMON), pick-up motor rotation direction signal (SDIR), and pick-up motor rotation speed control signal (SMPWM) and the operation of the pick-up roller. Table 71. Relationship between pick-up motor signals and the pick-up ...
  • HP 8550 | Service Manual - Page 279
    Controlling the belt motor The belt motor is a dc motor. The microprocessor (Q1) on the DADF controller PCB sends the belt motor drive signal (BMON), belt motor rotation direction signal (BDIR), and belt motor rotation speed control signal (BMPWM) to the drive circuit. When the belt motor begins to...
  • HP 8550 | Service Manual - Page 280
    Table 72 shows the relationship between the belt motor drive signal (BMON), belt motor rotation direction signal (BDIR), belt motor rotation speed control signal (BMPWM), and the feeding belt. Table 72. Relationship between belt motor drive signal and the feeding belt Belt motor drive signal (BMON...
  • HP 8550 | Service Manual - Page 281
    ... PCB, and a jam is detected in terms of the presence or absence of paper at a specific sensor at the time. When a jam is detected, the ADF communicates the fact to the copy module in the form of a code. The copy module reports the results of these on the LCD and in service mode. EN ADF 279
  • HP 8550 | Service Manual - Page 282
    Table 74. Jam detection Function Jam Type Pick-up Original retraction Sensor S1, S7 Description Sensor S7 does not detect the leading edge of an original 1500 msec after the pick-up motor (M1) has turned on and, in addition, sensor S1 does not detect an original. Sensor S7 does not detect the ...
  • HP 8550 | Service Manual - Page 283
    Table 74. Jam detection (continued) Function Jam Type Delivery Delivery Delivery Upper cover open Jam original Sensor MS2, S4 S1 Description Code The upper cover is open while the ADF is in operation. 82H Sensor S1 does not detect the original delivered on the 83H document tray. 84H ...
  • HP 8550 | Service Manual - Page 284
    ... terms of the presence/absence of paper over a specific sensor. When the ADF detects an improperly placed original, it communicates the fact to the copy module. The copy module will report the results of these codes as errors on the LCD and in service mode. 282 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 285
    .... The original that is picked up is Stops operation immediately a non-standard size. upon detection. 1. The original that is picked up is of a type not supported by reduced page composition mode, or 2. The original that is picked up is of a size different from the size of the first original. Stop ...
  • HP 8550 | Service Manual - Page 286
    When a jam occurs, the copy module remembers how many originals have been copied. The count is sent to the ADF after jam removal, and the ADF circulates the originals that have been copied; it then places originals that have not been copied on the copyboard for copying. This is the reason normal ...
  • HP 8550 | Service Manual - Page 287
    Power supply Figure 173 is an outline of the power supply system in the ADF. The power supply is provided by the copy module with 24 V dc (24 VP, 24 VL). l 24 VP is mainly used for loads and is cut off when the ADF is opened or its upper cover is opened. The circuit breaker (CB1) operates to cut ...
  • HP 8550 | Service Manual - Page 288
    Motors, solenoids, and sensors Figure 174. Motors, solenoids, and sensors Table 77. Motors, solenoids, and sensors Name Motor Notation M1 M2 M3 M4 M5 Description Pick-up motor ADF motor Belt motor Recirculating motor Delivery motor Clutch Belt motor brake Stopper plate solenoid Paper-retaining-...
  • HP 8550 | Service Manual - Page 289
    PCBs Figure 175. PCB locations Table 78. PCB functions Name DADF controller PCB Indicator PCB Notation 1 2 Description Controls ADF Indicates the presence of an original EN ADF 287
  • HP 8550 | Service Manual - Page 290
    ... and check pins noted and referenced. Adjusting others may cause damage. General timing charts The following are the signal names and abbreviations used in this manual and circuit diagrams. Note The abbreviations in parentheses are analog signals, which cannot be expressed in terms of '1' and '0'. ...
  • HP 8550 | Service Manual - Page 291
    Table 80. Names and abbreviations of signals Abbreviation Name of signal BDIR BK BMCLK BMON BMPWM CL CNCT CVRSW DCTS EJTS1 EJTS2 ENTS EPMS FLPSL1 FMCLK FMPWM ORGLED RFC RSDRV RSIN RSOUT RSS SDIR SMON SMPWM SPRS STPSLD SUPCC TURNS WGTSL WIDTH BELT MOTOR ROTATION Command BRAKE DRIVE Command BELT ...
  • HP 8550 | Service Manual - Page 292
    Figure 177. ADF general circuit diagram 290 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 293
    EN ADF 291
  • HP 8550 | Service Manual - Page 294
    Figure 178. ADF controller circuit diagram (1 of 7) 292 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 295
    EN ADF 293
  • HP 8550 | Service Manual - Page 296
    Figure 179. ADF controller circuit diagram (2 of 7) 294 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 297
    EN ADF 295
  • HP 8550 | Service Manual - Page 298
    Figure 180. ADF controller circuit diagram (3 of 7) 296 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 299
    EN ADF 297
  • HP 8550 | Service Manual - Page 300
    Figure 181. ADF controller circuit diagram (4 of 7) 298 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 301
    EN ADF 299
  • HP 8550 | Service Manual - Page 302
    Figure 182. ADF controller circuit diagram (5 of 7) 300 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 303
    Figure 183. ADF controller circuit diagram (6 of 7) Figure 184. EN ADF controller circuit diagram (7 of 7) ADF 301
  • HP 8550 | Service Manual - Page 304
    Figure 185. ADF display board 302 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 305
    Figure 186. ADF general timing chart (top pick-up mode, A4, and 2 originals-single-sided original to single copy) EN ADF 303
  • HP 8550 | Service Manual - Page 306
    ...operating sequence and serial communications between the printer formatter and the side HCI. The deck ... and motors, in response to signals fed from the printer formatter via the serial (Clink) interface.... sensor, switch and other information to the printer formatter, via the serial (C-link) interface....
  • HP 8550 | Service Manual - Page 307
    Figure 188. Deck controller PCB EN Side HCI 305
  • HP 8550 | Service Manual - Page 308
    Figure 189. Deck controller PCB output 306 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 309
    ...is paper in the side HCI. When the pick-up start signal is transmitted from the printer formatter, the deck controller PCB starts turning the pick-up motor ...before the next pick-up operation starts, the deck controller PCB notifies the printer formatter that there is no more paper. 2 1 3 4 Figure...
  • HP 8550 | Service Manual - Page 310
    Figure 191. Pick-up feed signals 308 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 311
    Figure 192. Signal transfer points Figure 193. Pick-up signal levels EN Side HCI 309
  • HP 8550 | Service Manual - Page 312
    Lifter operation The lifter in the side HCI is suspended by two wires. The wires are operated by the lifter motor (M1: stepping motor). When the right upper cover open sensor (PS1) detects that the upper right door has been opened, the deck controller PCB reverses the lifter motor and lowers the ...
  • HP 8550 | Service Manual - Page 313
    Remaining paper detection mechanism The remaining paper detection switch 1 (SW601) and the remaining paper detection switch 2 (SW602) on the remaining paper detection PCB are pressed through the lifter ascending movement and the swing arm operation. The combination of the on/off status of these two...
  • HP 8550 | Service Manual - Page 314
    Paper-size-detection mechanism The copy module detects paper size through the use of a paper-sizedetection switch (MS3). This switch is activated by a notch in the paper-size indication plate. The switch activates when the paper-sizedetection plate is set to the A4 side. The switch is not active ...
  • HP 8550 | Service Manual - Page 315
    ... stored in memory. When the microprocessor calculates that a paper jam has occurred, it notifies the printer main unit to stop the pick-up operation and tells the printer formatter that a paper jam has occurred. l Pick-up delay jam-The microprocessor assumes that a ...
  • HP 8550 | Service Manual - Page 316
    ...system. When the power switch of the copy module and printer are turned on, the printer formatter outputs a power on signal (PWRON) to the...switch on the copy module, and correct the problem on the load side before turning on the printer assembly power switch. 314 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 317
    Sensors Figure 201. Sensors Table 82. Sensor functions Name Photo interrupter Signal PS1 PS2 PS3 PS4 PS5 Function Upper right cover open detection sensor Second-sheet-detection sensor Paper-detection sensor Lifter upper-limit-detection sensor Feed sensor EN Side HCI 315
  • HP 8550 | Service Manual - Page 318
    Solenoids and motors Figure 202. Solenoids and motors Table 83. Solenoid and motor functions Name Solenoid Motors Signal SL1 M1 M2 M3 Function Pick-up solenoid Lifter motor Feed motor Pick-up motor 316 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 319
    PCBs 1 4 3 2 Figure 203. PCBs Table 84. PCB functions Number 1 2 3 4 Name Deck controller PCB Power supply unit Remaining paper detection PCB LED PCB Function Control and detection of loads Power supply Detects paper remaining in the side HCI Displays unit status EN Side HCI 317
  • HP 8550 | Service Manual - Page 320
    ... by PCB Only the LEDs and check pins that need to be checked during field service are listed below. Note Check pins not listed below are only for factory ... require a great degree of accuracy and must not be touched during field service. Some LEDs leak a small amount of current even when normal, and ...
  • HP 8550 | Service Manual - Page 321
    Deck controller PCB Figure 204. Deck controller PCB Table 85. Deck controller switches and LEDs Number SW201 (1 through 4) LED202 Function Switch for operation check. Inspect for servicing EN Side HCI 319
  • HP 8550 | Service Manual - Page 322
    User LED PCB Figure 205. User LED PCB Table 86. User LED LED number LED1 Function LED to be inspected by the user Remaining-paper-detection PCB Figure 206. Remaining-paper-detection PCB 320 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 323
    Input and output signals to the deck controller PCB Table 87. Signal names and codes Connector J201 Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Code TXI GND RXO CONTO +24V CKI GND GND GND +24V GND STRBI PWRON-IN GND +24V TXO GND RXI CONTI +24V CKO GND GND GND +24V GND STRBO PWRON-OUT GND +24V I/O ...
  • HP 8550 | Service Manual - Page 324
    Table 87. Signal names and codes (continued) Connector J203 Pin 1 2 3 4 5 6 Code +24V +24V PWRON-IN +5V GND GND GND DKSET LLLMT NC PPRSIZE GND GND PAP-VOL1 PAP-VOL2 DRVAD DRVAND DRVBD DRVBND FED1AD FED1AND FED1BD FED1BND NC NC +5VB2 GND 2NDPPR +5VB1 GND DROPN PUPSLD +24V I/O Input Input Output ...
  • HP 8550 | Service Manual - Page 325
    Table 87. Signal names and codes (continued) Connector J212 Pin 1 2 3 4 5 6 7 8 9 Code +5VB5 GND PPREXT +5VB4 GND UPRLMT +5VB3 GND PPREXT LED R LED G GND I/O Signal name Paper feed detect signal Lifter upper limit detect signal Paper detect signal Output Output Red LED lit-up signal Green ...
  • HP 8550 | Service Manual - Page 326
    General circuit diagram Upper right cover open detect sensor Second sheet detection sensor Pick-up motor Pick-up solenoid Deck Lifter motor M1 Remaining paper detection PCB Deck set detection switch Feed motor M2 Figure 207. 324 Deck controller PCB general circuit diagram EN Chapter - 5 ...
  • HP 8550 | Service Manual - Page 327
    Paper detection sensor Lifter upper detection sensor Feed sensor J J J Controller PCB J Lifter lower limit detection switch Paper size detect switch EN Side HCI 325
  • HP 8550 | Service Manual - Page 328
    326 Chapter - 5 Theory of operation EN
  • HP 8550 | Service Manual - Page 329
    ... left cover...335 Removing the rear cover ...336 Removing the upper front cover ...337 Removing the scanner motor ...338 Removing the scanner motor driver PCB ...339 Removing DIMMs on the reader controller PCB ...340 Removing the control panel ...344 Removing the LCD assembly ...346 Removing the ...
  • HP 8550 | Service Manual - Page 330
    ... the delivery roller unit (bottom pick-up mode)...410 Removing the delivery roller unit (top pick-up mode)...412 Removing the reversing guide ...419 Removing the stopper plate solenoid ...422 Positioning the paper-retaining plate solenoid (SL2) ...420 Positioning the paper-deflecting solenoid (SL3) ...
  • HP 8550 | Service Manual - Page 331
    Side HCI ...434 Identifying the external covers ...434 Removing the upper left cover...435 Removing the front cover ...435 Removing the rear cover ...436 Removing the upper right cover ...436 Removing the pick-up unit ...437 Removing the pick-up roller ...440 Removing the feed roller and separation...
  • HP 8550 | Service Manual - Page 332
    330 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 333
    Required tools You will need the following tools to perform service on the HP Color LaserJet 8550MFP and its accessories: Table 88. Service tools Tool Name Mirror positioning tool Stop ring pliers Tension gauge (270-330g) Standard image ...
  • HP 8550 | Service Manual - Page 334
    ...off, the fans continue to operate to cool the printer (to prevent clumping of toner). Be sure to perform the following ... not operate the printer with any of its parts removed, unless otherwise instructed. Use standard... is not necessary. Pull the printer unit out of the stand when servicing, but do not...
  • HP 8550 | Service Manual - Page 335
    Copy module Identifying the external covers 1 Figure 208. Front view of copy module 1 2 3 Lower front cover Upper front cover Upper right cover 2 3 4 5 Figure 209. Rear view of copy module 4 5 6 Upper rear cover Rear cover Upper left cover 6 EN Copy module 333
  • HP 8550 | Service Manual - Page 336
    Removing the lower front cover 1 2 Remove two face plates and screws (callout 1). Detach the lower front cover (callout 2). 2 2 1 Figure 210. Removing the copy module lower front cover Removing the upper right cover 1 2 Note Remove four screws (callout 1). Detach the upper right cover (callout ...
  • HP 8550 | Service Manual - Page 337
    Removing the upper rear cover 1 2 Remove three rubber face plates and five screws (callout 1). Detach the upper rear cover (callout 2). 2 1 2 Figure 212. Removing the copy module upper rear cover Removing the upper left cover 1 2 3 Remove the upper rear cover (see above). Remove five screws (...
  • HP 8550 | Service Manual - Page 338
    Removing the rear cover 1 2 3 4 Note Remove the upper rear cover (see page 335). Remove the upper left cover (see page 335). Remove three screws (callout 1). Detach the rear cover (callout 2). Be sure to use the same toothed washers when reinstalling. There is an unused 8-pin connector located ...
  • HP 8550 | Service Manual - Page 339
    Removing the upper front cover 1 2 3 4 Remove the lower front cover (see page 334). Remove the control panel (see page 344). Remove four rubber face plates and four screws (callout 1). Detach the upper front cover (callout 2). 2 1 2 Figure 215. Removing the copy module upper front cover EN ...
  • HP 8550 | Service Manual - Page 340
    ... the copy module scanner motor 4 Note Detach the scanner motor (callout 3) with its support plate. There is an unused 9-pin connector located below the scanner ... When mounting the scanner motor, move the scanner motor and support plate to the right as far as possible by hand. This provides correct ...
  • HP 8550 | Service Manual - Page 341
    Removing the scanner motor driver PCB 1 2 3 4 Remove the lower front cover (see page 334). Disconnect three connectors (callout ...screws (callout 2). Free the cable from the cable clamp. Detach the scanner motor driver PCB. 2 2 1 2 Figure 217. Removing the copy module the scanner motor driver PCB...
  • HP 8550 | Service Manual - Page 342
    Removing DIMMs on the reader controller PCB Note The printer's copy module can be upgraded by either of the following methods: • Replacing the... 334). Disconnect three connectors, and remove two screws. Detach the scanner motor driver PCB (see page 339). Remove two screws (callout 1), and detach the...
  • HP 8550 | Service Manual - Page 343
    5 While opening the claws (callout 3) of the slot, lift and detach the ROM DIMM. 2 3 Figure 219. Opening the claws Figure 220. EN Lifting the ROM DIMM to detach Copy module 341
  • HP 8550 | Service Manual - Page 344
    To mount the ROM DIMM 1 Insert the ROM DIMM into the slot at an angle. Figure 221. Inserting the ROM DIMM 2 Shift the ROM DIMM down in the direction indicated by the arrows until a click is heard. Figure 222. CAUTION Engaging the ROM DIMM Do not force the ROM DIMM. It can crack. 342 Chapter -...
  • HP 8550 | Service Manual - Page 345
    ... ROM DIMM, perform the following steps at the copy module control panel: 1 2 3 4 5 6 From the service menu, press COPIER > FUNCTION > CLEAR > R-CON. From the ... From the service menu, press COPIER > FUNCTION > MISC-R > USE-LAMP. From the service menu, press COPIER > FUNCTION > CCD > CCD-ADJ. Turn the ...
  • HP 8550 | Service Manual - Page 346
    Removing the control panel 1 2 Remove the copy module lower front cover (see page 334). Disconnect two connectors (callout 1), and free the cable from the cable saddle. Further, free the scanner motor cable from the wire saddle. 2 1 Figure 223. CAUTION Control panel When securing the cable, be ...
  • HP 8550 | Service Manual - Page 347
    3 Remove five screws (callout 2), and detach the control panel (callout 3). 2 2 3 2 Figure 224. Detaching the control panel EN Copy module 345
  • HP 8550 | Service Manual - Page 348
    Removing the LCD assembly 1 2 Remove the control panel (see page 344). Disconnect the connector (callout 1), and remove the 11 screws (callout 2) to detach the metal plate on the LCD assembly. 2 2 1 2 Figure 225. Detaching the metal plate on the LCD assembly 3 4 Disconnect three connectors (...
  • HP 8550 | Service Manual - Page 349
    To route the scanner drive cable Note You will need a mirror positioning tool (FY9-3040-000CN) when mounting the scanner drive cable. 1 2 Remove the copyboard cover. Remove two screws (callout 1), and detach the right glass retainer cover (callout 2). 2 2 1 2 1 Figure 227. Copyboard glass 3 4 ...
  • HP 8550 | Service Manual - Page 350
    ... tray pullout (see page 347). 13 Remove two front horizontal reinforcing stays and the rear horizontal reinforcing stay. Note When replacing these parts, be sure to tighten the front and rear screws before tightening the side screws. Test the copyboard glass for correct fit. 348 Chapter - 6 ...
  • HP 8550 | Service Manual - Page 351
    14 Place the mirror 1 mount (callout 5) so that the metal cable clamp of mirror 1 is in view through the long hole in the front and rear plates (callout 6). 2 5 2 6 Figure 229. Securing the metal cable clamp (front view) 2 5 2 6 Figure 230. CAUTION Securing the metal cable clamp (rear view) ...
  • HP 8550 | Service Manual - Page 352
    15 Loosen the screws on the mirror positioning tool (FY9-3040000CN), and contract the arms fully. Figure 231. Mirror tool 16 Fit the mirror positioning tool (callout 7) between the mirror 1 mount and the mirror 2 mount, and insert the pin (callout 8) that comes with the positioning tool. Note ...
  • HP 8550 | Service Manual - Page 353
    2 7 Non-threaded hole 2 8 Figure 233. Detaching and reattaching the mirror positioning tool (rear view) 17 Secure the metal cable clamp that was temporarily secured in step 15 with two screws (callout 9) inside the long hole (callout 10) of the side plate. 2 9 2 10 Figure 234. Securing the ...
  • HP 8550 | Service Manual - Page 354
    18 Engage the scanner cable on the pulley and the hook as shown in figure 236. 8 8 Figure 236. Cable positioning 19 Detach the mirror positioning tool. 352 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 355
    Removing the flexible cable Note Do not disconnect the connector of the flexible cable connected to the mirror 1 mount except when replacing the mirror 1 mount. (The mirror can be cleaned without disconnecting the cable.) 1 Remove two screws (callout 1), and detach the right glass retainer cover (...
  • HP 8550 | Service Manual - Page 356
    4 Peel the warning label (callout 4) from the flexible cable (callout 5). 2 4 2 5 Figure 239. Releasing the connector to the flexible cable 354 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 357
    5 Push the inside claws inward (callout 6), and release the connector to the flexible cable (callout 5). 2 6 2 5 Figure 240. Disconnecting the flexible cable EN Copy module 355
  • HP 8550 | Service Manual - Page 358
    6 Using a small screwdriver (callout 7), push the two tables that hold the flexible cable (callout 5) to disconnect the flexible cable from the connector. 2 7 2 5 Figure 241. CAUTION Connecting the flexible cable When connecting the flexible cable to the connector, make sure that the metal area...
  • HP 8550 | Service Manual - Page 359
    Removing the scanning lamp and scanning lamp heater 1 2 3 Remove two screws, and remove the right glass retainer cover or jump board if the ADF is installed (page 347). Remove the copyboard glass. Remove the screw and plate (callout 1), and detach the scanning lamp cover (callout 2). 2 1 2 ...
  • HP 8550 | Service Manual - Page 360
    6 Remove two screws (callout 5), and detach the anti-reflecting plate (callout 6). Note These screws are difficult to remove for the first time. Take care to use the correct screwdriver (a Phillips #2 screwdriver) and not damage the screw heads. If necessary, use needle nose pliers to assist in ...
  • HP 8550 | Service Manual - Page 361
    CAUTION When mounting the anti-reflecting plate, be sure to fit the anti-reflecting plate securely into the cut-off (front, rear) (callout 7) in the mirror 1 mount. Further, be sure to fit the lamp heater connector (in step 7) to the anti-reflecting plate. Failure to do so will inhibit free ...
  • HP 8550 | Service Manual - Page 362
    7 Disconnect the connector (callout 8), and remove two screws (callout 9). 2 10 2 8 2 9 Figure 246. Removing the scanning lamp 8 2 11 Detach the scanning lamp (callout 10) from the electrode plate (front) (callout 11) by pulling the assembly toward the front. CAUTION Avoid touching the ...
  • HP 8550 | Service Manual - Page 363
    When replacing the scanning lamp: l l l l Do not work when the surface of the scanning lamp is hot. Do not leave fingerprints on the surface of the scanning lamp. If the surface of the scanning lamp is soiled, wipe it with a clean, soft, dry cloth. When mounting the scanning lamp heater to the ...
  • HP 8550 | Service Manual - Page 364
    l When mounting the copper heater ring (callout 1), be sure to locate it about 4 to 8 mm from the light-emitting section of the lamp (callout 2). 2 1 2 2 Figure 249. Scanning lamp adjustment l When mounting a new scanning lamp, or when removing and then remounting the existing lamp, be sure to ...
  • HP 8550 | Service Manual - Page 365
    ...1 Figure 250. White plate cover removal 4 Remove four screws (callout 2), and detach the standard white plate (callout 3). 2 2 3 Figure 251. Note Replacing the white plate cover When replacing the standard white plate, be sure to make service mode adjustments (see page 84). Copy module 363 EN
  • HP 8550 | Service Manual - Page 366
    Removing the intensity-detection PCB 1 2 3 Remove two screws, and detach the right glass retainer cover (page 347) or jump board if the ADF is installed. Remove the copyboard glass. Remove the screw (callout 1), and detach the claws (callout 2) while pushing them down. 2 2 1 Figure 252. ...
  • HP 8550 | Service Manual - Page 367
    Removing the lens-mount cover and CCD unit 1 2 3 Remove two screws, and detach the right glass retaining cover. Remove the copyboard glass. Remove ten screws, and detach the lens-mount cover. 2 1 Figure 254. Lens mount cover 4 Remove four screws (callout 2), and detach the CCD unitretaining ...
  • HP 8550 | Service Manual - Page 368
    5 Remove the cable clamp (callout 5) from the copier, and disconnect two connectors (J101, J102) (callout 6). 2 5 2 5 2 6 Figure 256. CCD unit connectors 6 Detach the CCD unit. CAUTION Do not move the mirror 1 mount to the left or right, or turn on the power to make copies. If you do so, ...
  • HP 8550 | Service Manual - Page 369
    ... covers, two screws). Disconnect three connectors, and remove two screws, holding the scanner motor driver PCB. Detach the scanner motor driver PCB (see page 339). Remove two shoulder screws (callout 1), and disconnect eight connectors (callout 2). 2 2 1...
  • HP 8550 | Service Manual - Page 370
    7 8 Note Remove the copyboard cover, copy module upper rear cover, upper left cover, and rear cover, in that order. Remove seven screws (callout 5). Refer to figure 259 below for help in locating the seven screws. Figure 259. Removing the reader controller PCB cover (1 of 2) 2 5 2 5 Figure ...
  • HP 8550 | Service Manual - Page 371
    9 Pull out the electric unit (callout 6) to the rear, as shown. 2 6 Figure 261. CAUTION Removing the electrical unit When pulling out the electrical unit to the rear, you might hear some rough noise caused by plastic film rubbing against a metal plate. Ignore the noise. When putting the ...
  • HP 8550 | Service Manual - Page 372
    Removing the reader controller PCB 1 2 Remove the electrical unit pullout (page 367). Remove seven screws (callout 1), and detach the electrical unit RFI cover (callout 2). 2 2 1 Figure 263. Detaching the electrical unit cover 3 4 Disconnect eight connectors (callout 3) and six screws (callout ...
  • HP 8550 | Service Manual - Page 373
    ... pullout (page 367). Perform the work through step 10 provided for the removal of the reader controller PCB (see page 404). Remove two screws (callout 1), and detach the ECO-2 PCB (callout 2) from the two PCB supports (callout 3). 2 3 2 2 3 2 1 Figure 265. ECO PCB replacement EN Copy module 371
  • HP 8550 | Service Manual - Page 374
    Removing the AP-IP PCB 1 2 3 4 Remove the electrical unit pullout (see page 367). Remove the ECO PCB (see page 371). Disconnect three connectors (callout 1), and remove seven screws (callout 2). Detach the AP-IP PCB (callout 3). 2 2 2 3 2 1 2 Figure 266. AP-IP PCB removal 372 Chapter - 6 ...
  • HP 8550 | Service Manual - Page 375
    Removing the copy module main power supply PCB (DCP1) 1 2 Remove the copy module upper rear cover, upper left cover, and rear cover, in that order. Disconnect nine connectors (callout 1), and remove five screws (callout 2). 1 2 Figure 267. Removing the copy module main power supply PCB (DCP1) 3 ...
  • HP 8550 | Service Manual - Page 376
    Removing the accessories power supply PCB (DCP2) 1 2 Remove the copy module upper left cover, upper rear cover, and rear cover. Disconnect the connector (J1801) (callout 1), and remove three screws (callout 2). 2 2 1 Figure 268. Accessory power supply 3 Disconnect connectors J1802 and J1804, and ...
  • HP 8550 | Service Manual - Page 377
    Removing the power supply cooling fan (FM4) 1 2 3 Remove the copy module upper rear cover, upper left cover, and rear cover, in that order. Disconnect the connector, and remove two screws (callout 1). Detach the fan. 2 1 Figure 269. CAUTION Power supply cooling fan When mounting the fan (FM4), ...
  • HP 8550 | Service Manual - Page 378
    Removing the inverter PCB unit 1 2 3 4 5 Remove the copy module upper left cover, upper rear cover, and rear cover. Remove the electrical unit pullout (see page 367). Remove the copy module main power supply PCB (see page 373). Disconnect three connectors (callout 1), and remove two screws (callout...
  • HP 8550 | Service Manual - Page 379
    Automatic document feeder (ADF) Note The only serviceable part of the ADF is the large white feeding ... feeding belt" on page 431.) The remainder of the ADF will be serviced via adjustment/ calibration (see "ADF ...) and cleaning (see "Cleaning ADF parts" on page 167), or, only when necessary, wholeunit ...
  • HP 8550 | Service Manual - Page 380
    Removing the ADF CAUTION The ADF should be removed from the copier and placed on a table before servicing. Failure to do so may result in personal injury or damage to the ADF. 1 2 3 Turn off the copier. Disconnect the communication cable of the ADF from the copier. Open the ADF fully. Figure 272. ...
  • HP 8550 | Service Manual - Page 381
    ... ADF from the copier, you must fully open it to disengage these locks. When removing the ADF from the copier, be sure to hold it as shown in figure 273 above. Do not support it by the delivery assembly, which might create or cause subsequent faulty delivery. EN Automatic document feeder (ADF) 379
  • HP 8550 | Service Manual - Page 382
    Removing the body cover 1 Remove seven mounting screws (callout 1), and detach the body cover. 2 1 Figure 274. Mounting screws 2 1 2 1 Figure 275. Body cover 2 1 2 1 Figure 276. Mounting screws 380 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 383
    2 Remove two mounting screws (callout 2), and detach the document tray (callout 3). CAUTION The document tray is connected with a cable. Take extra care not to damage the cable during work. 2 3 2 Figure 277. Document tray EN Automatic document feeder (ADF) 381
  • HP 8550 | Service Manual - Page 384
    ...width than 297 mm is used, the side guide lock must be removed. 1 2 Loosen the screw ...lock (callout 2). 2 2 1 Figure 278. CAUTION Side guide When making copies, be sure to adjust the side... to the size of the original. If the side guide is improperly positioned, the original will tend to move askew...
  • HP 8550 | Service Manual - Page 385
    Mounting the original-width detecting volume 1 Loosen two screws (callout 1), and detach the side guide (callout 2). 2 2 1 Figure 279. Side guide and screws 2 Fully open the side guide at the rear (callout 3) and the front (callout 4). 2 3 2 4 Figure 280. ...
  • HP 8550 | Service Manual - Page 386
    3 Mount the gear (callout 5). 2 5 Figure 281. Mounting the gear 4 Turn the original-width detecting volume (callout 6) fully in the direction of the arrow; then, turn it in the opposite direction (equivalent to half a tooth) to the position indicated in the figure. 2 6 Figure 282. Setting ...
  • HP 8550 | Service Manual - Page 387
    ... (callout 8). Connect the connector (callout 9). 6 2 7 2 9 2 8 2 6 Figure 283. Setting the screws and mounting lock 7 Mount the side guide lock removed in step 1, and execute adjustments to the original-width detecting volume. (For adjustments, see p. 518.) Removing the pick-up motor unit 1 2 3 ...
  • HP 8550 | Service Manual - Page 388
    4 Remove the screw (callout 3), and remove the cable guide (callout 4). 2 3 2 4 Figure 285. Pick-up motor cable guide 5 6 Disconnect the connector (callout 5) on the upper cover sensor S4. Remove two mounting screws (callout 6), and detach the pick-up ...
  • HP 8550 | Service Manual - Page 389
    ... J11 (callout 1) from the ADF controller PCB (callout 2). 2 1 2 Figure 287. Feeder motor unit 4 Remove two screws (callout 3), and disconnect the connector (callout 4) of the ADF motor color sensor S9. 2 3 2 4 2 3 Figure 288. Feeder motor color sensor EN Automatic document feeder (ADF) 387
  • HP 8550 | Service Manual - Page 390
    5 Detach two drive belts (callout 5), and detach the ADF motor unit (callout 6). 2 5 2 6 Figure 289. Feeder motor drive belts 388 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 391
    Removing the belt motor 1 2 3 4 Remove the ADF from the copier (see page 378). Remove the ADF motor unit (see page 387). Remove the tie-wrap as necessary. Disconnect connectors J6 (callout 1), J7 (callout 3), and J13 (callout 3) on the ADF controller PCB. 2 3 2 1 Figure 290. Belt motor 5 2 ...
  • HP 8550 | Service Manual - Page 392
    6 Using a pencil, mark the position of the belt motor count (callout 5) on the ADF, and then remove three screws (callout 6). 2 6 2 5 Figure 292. Belt motor count position 7 Detach the feeding belt drive roller side (callout 7) of the timing belt (callout 8), and detach the belt motor unit (...
  • HP 8550 | Service Manual - Page 393
    To make adjustments 1 Secure the belt motor unit (callout 1) in place with three screws (callout 2) so that the displacement is 3 ±1 mm when the timing belt (callout 3) is pushed under a force of 3 ±1 mm. 2 1 2 3 Figure 294. Replacing the belt motor 2 2 Pull the belt tensioner (callout 4) ...
  • HP 8550 | Service Manual - Page 394
    Removing the clutch unit 1 2 Remove the belt unit (callout 1). Detach the drive belt (callout 2). 2 1 2 Figure 296. Clutch unit 3 4 Remove the E-ring (callout 3). Displace the bushing (callout 4), and remove the clutch unit (callout 5). 2 4 2 3 2 5 Figure 297. E-ring and bushing 392 Chapter -...
  • HP 8550 | Service Manual - Page 395
    Note When mounting the clutch unit, be sure that the slip stop (callout 6) of the clutch engages with the stopper (callout 7) of the mount. 2 6 2 7 Figure 298. Clutch unit slip stop EN Automatic document feeder (ADF) 393
  • HP 8550 | Service Manual - Page 396
    Removing the delivery motor 1 2 Remove the body cover (see page 380). Disconnect three connectors (callout 1). 2 1 Figure 299. Delivery motor connectors 3 4 Remove two screws (callout 2), and free the cable (callout 3) from the cable retainer (callout 4). Detach the delivery monitor unit (...
  • HP 8550 | Service Manual - Page 397
    5 6 Disconnect the connector (callout 6), and remove two screws (callout 7). Detach the delivery motor (callout 8). 2 6 2 8 2 7 Figure 301. Detaching the delivery motor EN Automatic document feeder (ADF) 395
  • HP 8550 | Service Manual - Page 398
    Removing the pick-up roller 1 2 Remove the body cover (see page 380). Remove two screws (callout 1), and detach the document tray mount (callout 2). 2 1 2 Figure 302. Document tray mount 3 Remove the screw (callout 3), and detach the paper-retaining solenoid (callout 4). 2 3 2 4 Figure 303. ...
  • HP 8550 | Service Manual - Page 399
    4 Remove two screws (callout 5), and detach the original inlet guide plate (callout 6). 2 6 2 5 Figure 304. Inlet guide plate 5 6 Rotate the pick-up roller (callout 7) to the position shown in the figure. Remove the screw (callout 8), and detach the pick...
  • HP 8550 | Service Manual - Page 400
    Removing the separation belt unit 1 2 Remove the body cover (see page 380). Detach the reversing roller drive belt (callout 1). 2 1 Figure 306. Reversing roller drive belt 3 Remove two screws (callout 2), and detach the separation belt unit (callout 3) together with the fixing plate (callout 4). ...
  • HP 8550 | Service Manual - Page 401
    ... (see page 396). Remove the original inlet guide plate (see page 397). Remove the ... four screws (callout 1), and detach the separation guide plate (callout 2). 2 2 1 2 1 Figure 308. Separation guide... two screws (callout 3), and detach the inside guide plate (callout 4). 2 4 2 3 Figure 309. Inside ...
  • HP 8550 | Service Manual - Page 402
    7 Remove the screw (callout 5), and detach the stopper (callout 6). 2 5 2 6 Figure 310. Roller unit stopper 8 9 Remove the E-ring (callout 7), and detach the idler gear (callout 8). Remove the E-ring (callout 9), and detach the gear (callout 10) and the timing belt (callout 11). (Take care not...
  • HP 8550 | Service Manual - Page 403
    10 Remove the E-ring (callout 12), and shift the arm (callout 13) and the gear (callout 14) in the direction of the arrow. 2 14 2 12 2 13 Figure 312. Removing the E-ring, arm, and gear 11 Remove the E-ring (callout 15), and shift the bushing (callout 16) in the direction of the arrow. 12 Remove...
  • HP 8550 | Service Manual - Page 404
    Removing the registration roller 1 2 3 4 5 Remove the ADF from the copier (see page 378). Remove the body cover (see page 380). Remove the feeding roller unit (see page 399). Remove the pick-up motor unit (see page 385). Remove four screws (callout 1), and detach the right hinge unit (callout 2). ...
  • HP 8550 | Service Manual - Page 405
    7 Remove the screw (callout 5), and detach the solenoid mount (callout 6). 2 5 2 6 Figure 316. Solenoid mount 8 9 Remove the spring (callout 7) and the screw (callout 8). Detach the arm (callout 9). 2 7 2 9 2 8 Figure 317. Detaching the spring, screw, and arm EN Automatic document feeder (...
  • HP 8550 | Service Manual - Page 406
    10 Remove the E-ring (callout 10) and the bushing (callout 11). 11 Detach the link arm shaft (callout 12). 2 11 2 12 2 10 Figure 318. Link arm shaft 12 Remove two screws (callout 13), and remove the sensor mount (callout 14). 2 14 2 13 Figure 319. Sensor mount 404 Chapter - 6 Removal and ...
  • HP 8550 | Service Manual - Page 407
    13 Remove the E-ring (callout 15), tension spring (callout 16), bushing (callout 17), and two screws (callout 18). 2 18 2 16 2 17 2 15 2 18 Figure 320. Tension spring 14 Remove the grip ring (callout 19), clock plate (callout 20), sensor mount (callout 21), and spring (callout 22). 21 2 2 20 2...
  • HP 8550 | Service Manual - Page 408
    15 Remove the grip ring (callout 23), tension spring (callout 24), bushing (callout 25), and two screws (callout 26). 16 Detach the registration roller (callout 27). 2 26 2 25 2 24 2 23 2 26 Figure 322. Registration roller 2 27 406 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 409
    Removing the delivery/reversing roller 1 2 3 4 Remove the ADF from the copier (see page 378). Remove the body cover (see page 380). Remove the registration roller (see page 402). Remove two E-rings (callout 1), gear (callout 2), timing belt (callout 3), and bushing (callout 4). (Take care not to ...
  • HP 8550 | Service Manual - Page 410
    5 Note Remove the gear (callout 5). (Take care not to drop the pin.) Remove the gear while unlocking it. 2 5 Figure 324. Gear Figure 325. Unlocking and removing the gear 408 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 411
    ...(callout 6), and remove the bushing (callout 7). 2 7 2 6 Figure 326. Grip ring and bushing 7 8 Remove the spring (callout 8) and the screw (callout 9). Detach the lower guide stopper (callout 10). 2 9 2 8 2 10 Figure 327. Detaching the lower guide stopper EN Automatic document feeder (ADF) 409
  • HP 8550 | Service Manual - Page 412
    9 Remove the spring (callout 11). 2 11 Figure 328. Removing the spring 10 Remove the screw (callout 12), and detach the sensor cover (callout 13). 11 Disconnect the sensor connector (callout 14), and remove the registration sensor (callout 15) by lifting it. 2 12 2 13 Figure 329. Registration ...
  • HP 8550 | Service Manual - Page 413
    2 14 15 Figure 330. Disconnecting the sensor connector 12 Remove the paper guide (callout 16). 2 9 Figure 331. Paper guide EN Automatic document feeder (ADF) 411
  • HP 8550 | Service Manual - Page 414
    13 Remove two screws (callout 17) at the front and two screws (callout 18) at the rear. 14 Detach the reversing plate (callout 19) to the bottom. 2 17 Figure 332. Reversing plate (front view) 2 19 2 18 Figure 333. Detaching the reversing plate (rear view) 412 Chapter - 6 Removal and ...
  • HP 8550 | Service Manual - Page 415
    15 Remove four screws (callout 20), and remove the front plate (callout 21). 2 21 2 20 Figure 334. Front plate 16 Remove the delivery/reversing roller (callout 22). 2 22 Figure 335. Delivery/reversing roller EN Automatic document feeder (ADF) 413
  • HP 8550 | Service Manual - Page 416
    Removing the delivery roller unit (bottom pick-up mode) 1 2 3 Remove the body cover (see page 380). Remove the pick-up motor (see page 385). Remove two screws (callout 1). 2 1 Figure 336. Body cover 4 Remove the E-ring (callout 2). 2 Figure 337. E-ring 414 Chapter - 6 Removal and replacement...
  • HP 8550 | Service Manual - Page 417
    5 6 Remove the screw (callout 3), and remove the fixing pin (callout 4). Detach the delivery roller unit (callout 5). Figure 338. Delivery roller unit EN Automatic document feeder (ADF) 415
  • HP 8550 | Service Manual - Page 418
    Removing the delivery roller unit (top pick-up mode) 1 2 Remove the body cover (see page 380). Remove the screw (callout 1). 2 1 Figure 339. Removing the screw and spring 3 Disconnect the spring (callout 2) and the connector (callout 3). 2 2 3 Figure 340. Disengaging the connector 416 ...
  • HP 8550 | Service Manual - Page 419
    4 Remove two screws (callout 4), and detach the timing belt (callout 5) and the motor unit (callout 6). 2 5 2 4 2 4 2 6 Figure 341. Detaching the timing belt and motor unit EN Automatic document feeder (ADF) 417
  • HP 8550 | Service Manual - Page 420
    5 6 Remove the screw (callout 7) at the front and three screws (callout 8) at the rear. Detach the delivery roller unit (callout 9). 2 8 2 7 2 9 Figure 342. Detaching the delivery roller unit 418 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 421
    Removing the reversing guide 1 2 Note Remove the body cover (see page 380). Remove the gear (callout 1) and the timing belt (callout 2). Remove the gear while unlocking it. 2 2 1 Figure 343. Gear and timing belt Figure 344. Unlocking and removing the gear EN Automatic document feeder (ADF) ...
  • HP 8550 | Service Manual - Page 422
    ... the front side (callout 3) and the rear side (callout 4). 2 3 Figure 345. Reversing guide spring, front 2 4 Figure 346. Reversing guide spring, rear 4 Remove the screw (callout 5), and detach the solenoid unit (callout 6). 2 5 2 6 Figure 347. 420...
  • HP 8550 | Service Manual - Page 423
    ... 9), the spacer (callout 10), and the fixing pin (callout 11). Detach the reversing guide (callout 12). When mounting the fixing pin, be sure to return it to original position. 2 9 2 11 2 12 Figure 349. Detaching the reversing guide 2 10 EN Automatic document feeder (ADF) 421
  • HP 8550 | Service Manual - Page 424
    Removing the stopper plate solenoid 1 2 Remove the body cover (see page 380). Remove two screws (callout 1), and remove the document tray mounting plate (callout 2). 2 1 Figure 350. 2 2 1 Document tray mounting plate 3 4 Remove two screws (callout 3), and disconnect the connector (callout 4). ...
  • HP 8550 | Service Manual - Page 425
    To make adjustments Secure the solenoid (callout 1) in place where the rubber block stopper (callout 2) butts against the rear edge of the stopper plate (callout 3) when the plunger of the solenoid (callout 1) is at the end of its stroke. 2 3 2 2 1 Figure 352. Solenoid positioning EN ...
  • HP 8550 | Service Manual - Page 426
    Positioning the paper-retaining plate solenoid (SL2) 1 Prepare test strips. Cut a sheet of A4- or letter-size paper (64 g/m2) into thirds, to widths of about 70 mm each. 1/3 1/3 1/3 Vertical Figure 353. Test strips 2 3 70 mm (approx.) Remove the front cover and the body cover (see page 380). ...
  • HP 8550 | Service Manual - Page 427
    6 Push the test strip prepared in step 1 in between the delivery roller and the pick-up roller while pushing the plunger of the paper-retaining solenoid. Check to make sure the delivery roller rotates as the rear and front pick-up rollers are tested. Figure 355. Note Inserting the test strip ...
  • HP 8550 | Service Manual - Page 428
    Positioning the paper-deflecting solenoid (SL3) 1 2 Remove the body cover (see page 380). Loosen the fixing screw (callout 1), and tighten it when the stroke of the solenoid (callout 2) is 4.5 mm. 2 1 2 Figure 356. Paper-deflecting solenoid 426 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 429
    Removing the stamp solenoid 1 2 3 Remove the delivery roller unit (top pick-up mode) (see page 416). Remove the screw (callout 1) and spring (callout 2). Detach the flapper plate (callout 3). 2 2 3 Figure 357. Flapper plate 4 2 1 Remove the E-ring (callout 4) and the bushing (callout 5). 2 4 2...
  • HP 8550 | Service Manual - Page 430
    ... 7 8 2 7 Remove two screws (callout 10) at the front and two screws (callout 11) at the rear. Remove the paper-guide plate (callout 12). 2 11 2 12 2 10 Figure 360. Paper-guide plate 428 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 431
    9 Remove the sensor flag (callout 13), and disconnect the connector (callout 14). 2 13 2 14 Figure 361. Sensor flag and connector 10 Remove three screws (callout 15), and detach the delivery roller mount (callout 16). 2 16 2 15 Figure 362. Delivery roller mount 11 Remove the delivery roller (...
  • HP 8550 | Service Manual - Page 432
    12 Disengage two claws (callout 19) of the stamp solenoid mount (callout 18). 13 Detach the stamp solenoid (callout 20). 2 18 2 19 2 20 Figure 364. Stamp solenoid 430 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 433
    Removing the feeding belt 1 2 Remove the body cover (see page 380). Remove the spring (callout 1) at the front. 2 1 Figure 365. Spring 3 Note that the rear spring has a retaining hook for temporary storage of the spring. Free the spring (callout 2) from the hook (callout 3) at the rear, and ...
  • HP 8550 | Service Manual - Page 434
    4 Remove the screw (callout 5), and detach the solenoid and cable (callout 6). Note Take care not to drop the pin in the solenoid arm. 2 5 2 6 Figure 367. Detaching the solenoid 5 Remove four screws (callout 7), and detach the side plate (callout 8). 2 8 2 7 2 7 Figure 368. Detaching the ...
  • HP 8550 | Service Manual - Page 435
    .... Delivery unit linking plate 7 Pull off the feeding belt (callout 11) to the front. 2 11 Figure 370. Note Removing the feeding belt When replacing the belt, take care not to rub or catch the belt on protruding sheet-metal parts. This can damage the belt. EN Automatic document feeder (ADF) 433
  • HP 8550 | Service Manual - Page 436
    Side HCI Identifying the external covers 2 2 3 2 1 Figure 371. External covers 2 4 Figure 372. Rear cover 1 2 3 4 Front cover Upper left cover Upper right cover Rear cover 434 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 437
    Removing the upper left cover Remove two screws (callout 1) and the upper left cover (callout 2). 2 1 Figure 373. Upper left cover and screws Removing the front cover 1 2 Remove the upper left cover (see above) and open the upper right cover. Remove two screws (callout 1) and the front cover (...
  • HP 8550 | Service Manual - Page 438
    Removing the rear cover 1 2 Remove the upper left cover and open the upper right cover. Remove three screws (callout 1) and the rear cover (callout 2). 1 2 Figure 375. Rear cover and screws 1 Removing the upper right cover 1 2 Remove the upper left cover. Remove two screws (callout 1) and the ...
  • HP 8550 | Service Manual - Page 439
    Removing the pick-up unit 1 2 3 Remove the upper right cover (see page 436). Remove the front cover (see page 435). Remove two screws (callout 1) and the paper-size limit panel (callout 2). 2 2 1 Figure 377. Paper-size limit panel EN Side HCI 437
  • HP 8550 | Service Manual - Page 440
    4 Remove two screws (callout 3), the fixing plate (callout 4), and the paper-size limit panel (callout 5). 2 5 2 3 2 4 2 3 Figure 378. Fixing plate and limit panel 438 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 441
    5 Remove four connectors (callout 6) to release the cable clamp (callout 7). 2 7 2 6 2 6 Figure 379. Connectors and cable clamps 6 Remove two screws (callout 8) and pull the pick-up unit (callout 9) toward you to remove it. 2 8 2 9 Figure 380. Pick-up unit EN Side HCI 439
  • HP 8550 | Service Manual - Page 442
    Removing the pick-up roller 1 2 Open the upper right cover (see page 436). Release the claw (callout 1) and remove the pick-up roller (callout 2) from the shaft. 2 2 1 Figure 381. Pick-up roller 440 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 443
    Removing the feed roller and separation roller 1 2 Remove the upper right cover (see page 436). Rotate the knobs (callout 1) to remove the feed roller (callout 2) and the separation roller (callout 3). 2 1 2 2 3 Figure 382. Feed roller and separation roller EN Side HCI 441
  • HP 8550 | Service Manual - Page 444
    Removing the lifter wire To remove parts in front of the lifter wire 1 2 Remove the upper left cover and the front cover (see page 435). Remove the screw (callout 1) and the bracket (callout 2). 2 2 1 Figure 383. Preparing to remove the lifter wire 3 Remove the E-ring (callout 3) and the pulley ...
  • HP 8550 | Service Manual - Page 445
    4 Remove the pulley cover (callout 5). 2 5 Figure 385. Pulley cover EN Side HCI 443
  • HP 8550 | Service Manual - Page 446
    5 Remove the screw (callout 6) and the lifter wire (callout 7). 2 6 2 7 Figure 386. Screw and lifter wire 444 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 447
    To remove parts behind the lifter wire 1 2 3 4 5 Remove the upper left cover (see page 435). Remove the rear cover (see page 436). Remove ... page 454). Remove three screws (callout 1) and the power supply mount (callout 2). 2 2 1 2 1 Figure 387. Parts removal behind the lifter wire EN Side HCI 445
  • HP 8550 | Service Manual - Page 448
    6 Remove four connectors (callout 3). 2 3 2 3 Figure 388. Connectors 7 Remove three screws (callout 4) and the remaining paperdetection unit (callout 5). 2 4 2 5 2 4 Figure 389. Paper-detection unit 446 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 449
    8 Remove two screws (callout 6) and the lifter drive unit (callout 7). 2 6 2 6 2 7 Figure 390. Lifter drive unit 9 Remove three screws (callout 8) and the rear panel (callout 9). 2 8 2 8 2 9 Figure 391. Rear panel EN Side HCI 447
  • HP 8550 | Service Manual - Page 450
    10 Remove the E-ring (callout 10) and the gear (callout 11). 2 11 2 10 Figure 392. E-ring and gear 11 Remove the E-ring (callout 12) and the pulley cover (callout 13). 2 13 2 12 Figure 393. E-ring and pulley cover 448 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 451
    12 Remove the screw (callout 14) and the bracket (callout 15). 2 15 2 14 Figure 394. Bracket removal EN Side HCI 449
  • HP 8550 | Service Manual - Page 452
    13 Remove the screw (callout 16) and the lifter wire (callout 17). 2 16 2 17 Figure 395. Lifter wire removal 450 Chapter - 6 Removal and replacement EN
  • HP 8550 | Service Manual - Page 453
    To tighten the lifter wire 1 2 3 Secure the bracket to the lifter with two screws (callout 1). Thread the lifter wire onto the upper pulley (callout 2). Load the spool of the lifter wire onto the pulley (callout 3) of the lifter drive shaft, and wind the wire around the pulley groove twice, by hand...
  • HP 8550 | Service Manual - Page 454
    Removing the lifter motor (M1) 1 2 3 4 Remove the upper left cover (see page 435). Remove the rear cover (see page 436). Remove the deck controller PCB (see page 453). Remove two screws (callout 1) and the lifter motor (M1) (callout 2). 2 1 2 Figure 397. Lifter motor (M1) Removing the feeder ...
  • HP 8550 | Service Manual - Page 455
    Removing the pick-up motor (M3) 1 2 Remove the upper left cover and the front cover (see page 435). Remove the connector (callout 1), two screws (callout 2), and the pick-up motor (M3) (callout 3). 2 1 2 3 2 Figure 399. Pick-up motor (M3) Removing the deck controller PCB 1 2 3 Remove the upper ...
  • HP 8550 | Service Manual - Page 456
    Removing the power supply PCB 1 2 3 4 Remove the upper left cover (see page 435). Remove the rear cover (see page 436). Remove the deck controller PCB (see page 453). Remove two screws (callout 1) and pull out the power supply PCB (callout 2) to remove it. 2 1 2 Figure 401. Power supply PCB 454...
  • HP 8550 | Service Manual - Page 457
    ... not identified by error codes ...519 Using the copy module service mode to test parts . . 526 ADF troubleshooting ...528 Fault isolation ...528 Numbered ... DADF controller PCB...534 Side HCI troubleshooting ...535 Overview ...535 User and service LEDs ...536 Sensor and switch ...
  • HP 8550 | Service Manual - Page 458
    456 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 459
    ... are in good condition. l The printer has been maintained on a regular basis as described in chapter 4 of the HP Color LaserJet 8500/8550 Printer Family Service Manual. Note the location of any spilled or accumulated toner before troubleshooting. Toner ...
  • HP 8550 | Service Manual - Page 460
    ... power requirements for the system have been met. If the control panel display on the printer is not working, see the HP Color LaserJet 8500/8550 Printer Family Service Manual. If the control panel display on the copy module is not working, see ...
  • HP 8550 | Service Manual - Page 461
    ... from the multipurpose tray (tray 1), tray 2, tray 3, or tray 4, see chapter 7, Troubleshooting, in the HP Color LaserJet 8500/8550 Printer Family Service Manual. ... appear in printed pages, see chapter 7, Troubleshooting, in the HP Color LaserJet 8500/8550 Printer Family Service Manual. ...
  • HP 8550 | Service Manual - Page 462
    ... dc controller PCB (printer part) See "To replace the dc controller PCB" on page 120. Also see the HP Color LaserJet 8500/8550 Printer Family Service Manual for the procedure to change the dc controller PCB hardware. See "To replace the ECO-2 PCB...
  • HP 8550 | Service Manual - Page 463
    l Standard white plate See "To replace the standard white plate" on page 134. See "To replace the AP-IP PCB" on page 134. l AP-IP PCB EN Copy module troubleshooting 461
  • HP 8550 | Service Manual - Page 464
    Image fault troubleshooting Initial checks Environment l l The voltage must be ± 10% of the requirements noted in chapter 1 of this manual. The copier must not ...be well ventilated. The copier must be kept level. The power plug of the printer unit must be connected to the copy module, and the power ...
  • HP 8550 | Service Manual - Page 465
    ... sure that they are properly mounted. Paper Media should meet the specifications outlined by HP. See the media guidelines on page "Supported media" on page 29. Also check the HP Media Specifications Guide. Environmental factors can affect media; try some new ...
  • HP 8550 | Service Manual - Page 466
    ... stock and shows composite and primary colors, halftone images, halftone grayscale, and ...target provides a good baseline against which to troubleshoot. It will be particularly useful in escalated cases. While ... image that includes composite and primary colors, halftone images, halftone grayscale, and ...
  • HP 8550 | Service Manual - Page 467
    ... a test pattern Set the print count, print size, and color mode (effective if TYPE=3, 4, 5, or 6). 1 2 3 4 5 6 7 Start service mode. Press COPIER. Press TEST...7 to 9 Remarks Image from the CCD (normal copying) For R&D 256 colors 256 gradations 16 gradations Full-face halftone Grid ...
  • HP 8550 | Service Manual - Page 468
    ...light image). If the density of one color is low, the light-color toner cartridge is likely to be faulty. If the density of all colors is low, primary or secondary transfer is likely to ... right and left densities are uneven for all colors, the drum cartridge, secondary pre-transfer charging...
  • HP 8550 | Service Manual - Page 469
    ...of copier paper (the pattern is repeated). If a hue is wrong, the toner cartridge or the drum cartridge of the printer unit is likely to have deteriorated. Figure 404. 256-color test print EN Copy module troubleshooting 467
  • HP 8550 | Service Manual - Page 470
    ... 256-gradation test print to check gradation and balance among colors. l l Gradation-Check the full gradation between density 0 and ...in two colors. CAUTION If you specify a color in service mode (TEST > PG > COLOR-Y/M/C/K), do not specify three colors; doing so can cause a fusing fault that would ...
  • HP 8550 | Service Manual - Page 471
    ... between left and right, and balance between colors. l l l Gradation-If the density is not expressed in 16 gradations, the laser system of the printer unit is ... lines-If white lines occur in the image, the toner cartridge of the printer unit is likely to be faulty. Uneven density ...
  • HP 8550 | Service Manual - Page 472
    ... be soiled. White lines-If white lines occur at the same position in all colors, the intermediate transfer drum or the ...of the printer unit is likely to be faulty. If they occur at different positions or in one color, the toner cartridge of the printer unit is likely to be faulty. Uneven intervals-If...
  • HP 8550 | Service Manual - Page 473
    ...print (TYPE=6) Use the grid test print to check color displacement and alignment of angles and straight lines... displacement-If color displacement occurs, the intermediate transfer drum or the secondary transfer belt assembly of the printer unit is likely to be faulty. Often, color displacement occurs...
  • HP 8550 | Service Manual - Page 474
    CMYK 64-gradation test print (TYPE=12) Use the CMYK 64-gradation test print to check the gradation of all CMYK colors at a glance. Figure 409. CMYK 64-gradation test print 472 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 475
    RGB 64-gradation test print (TYPE=13) Use the RGB 64-gradation test print to check the gray color balance and the gradation in two-color RGB mode. Figure 410. RGB 64-gradation test print EN Copy module troubleshooting 473
  • HP 8550 | Service Manual - Page 476
    ... and the difference in density of each CMYK color. Fogging-If the white area is foggy, the photosensitive drum inside the drum cartridge or the laser system of the printer unit is likely to be faulty. Figure 411. Full-color 16-gradation test print 474 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 477
    ...CMYK) test print (TYPE=15) Use the full-color light area 16-gradation (CMYK) test ... the gray balance and the gradation of each CMYK color in light areas. Gray balance and the gradation...TYPE=14 test prints. Figure 412. Full-color light area 16-gradation test print EN Copy module troubleshooting 475
  • HP 8550 | Service Manual - Page 478
    ... images The copier generates a solid-black copy or an image in solid color The face or back of copy paper is soiled The copy has ... copy has a specific missing color The copy has white spots The copy has an inadequately fused toner image The copy has a distorted or color-displaced image The copy has ...
  • HP 8550 | Service Manual - Page 479
    ... Go to step 2. If the color is black only, go to step 3. Make a test print in service NO mode (TEST > PG > TYPE=14), YES and find the color that is light...the copy. Does the color appear on the test print? Are the contacts soiled on YES either of the following? l black toner cartridge l ...
  • HP 8550 | Service Manual - Page 480
    ... bias output) Is the contact for the color YES developing bias for the printer unit soiled? Open ... image on the surface of the photosensitive drum. Is the color toner image fully developed on the surface of the photosensitive ...? Open the right cover of the NO printer unit, and fit the door YES switch...
  • HP 8550 | Service Manual - Page 481
    ... controller PCB. YES Is the contact of the grounding wire of the drum cartridge or the contact of the drum grounding wire for the printer unit soiled? Are the contacts soiled on .../No Action YES Check the connectors and wiring to the AP-IP PCB and CCD driver PCB. EN Copy module troubleshooting 479
  • HP 8550 | Service Manual - Page 482
    ...copier generates a solid-black copy or an image in solid color Unit Copy module Cause Anti-counterfeit ...wiring between the AP-IP PCB and CCD driver PCB correct? Is dc power present at ...to execute intensity adjustment in service mode (FUNCTION > MISC-R > USE-LAMP). 480 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 483
    ... or back of the copy paper is soiled Unit Printer Cause Cassette pickup roller, registration.... 4 5 Wipe the surface of the intermediate transfer drum with a moistened flannel cloth; then, dry wipe... the worn or cracked part. 9 Replace the worn or cracked part. EN Copy module troubleshooting 481...
  • HP 8550 | Service Manual - Page 484
    ... in isolating repetitive image defects to the appropriate print engine part. For more information about repetitive image defects for the printer, see the HP Color LaserJet 8500/8550 Printer Family Service Manual. Table 91. Repetitive image defects ...
  • HP 8550 | Service Manual - Page 485
    ...the CCD with a NO blower brush. Is the problem corrected? Are there scratches in the peripheral direction (sub-scanning direction) of the photosensitive drum? YES Printer Photosensitive drum Upper fusing roller 4 Replace the photosensitive drum cartridge...
  • HP 8550 | Service Manual - Page 486
    ... Do the white bands or lines occur in a specific color only? Is the fusing/separation upper guide coated with toner? YES Printer 4 Replace the toner cartridge for the specific color. Clean the fusing/ separation upper guide. 5 Fusing/ separation upper guide ...
  • HP 8550 | Service Manual - Page 487
    ...Go to step 2. Go to step 6. Clean the soiled part. If the dirt cannot be removed, replace ...and the inverter PCB; if faulty, replace the part. Remove the impediment to smooth movement. End....YES the surface of the CCD with a NO blower brush. Is the problem corrected? EN Copy module troubleshooting 485
  • HP 8550 | Service Manual - Page 488
    ... malfunction? Is the missing color black? Yes/No Action YES Replace the problem cartridge. Tonerlevel detection 2 YES No See the printer service manual. See the printer service manual. 486 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 489
    The print has white spots Unit Printer Cause Toner cartridge Photosensitive drum unit Step 1 2 Checks Yes/No Action Replace the ... cartridge. Replace the problem part. Are any of the developing cylinders YES of the toner cartridge defective? Is the photosensitive drum or the ...
  • HP 8550 | Service Manual - Page 490
    .... Clean the upper or lower fusing thermistor. Replace the dc controller PCB. 2 YES NO The copy has a distorted or color-displaced image Unit Printer Cause Drum motor drive assembly Laser/ scanner assembly Step 1 Checks Yes/No ...
  • HP 8550 | Service Manual - Page 491
    ... copy has a smudged or uneven image Unit Printer Cause Separation sensor Fusing assembly Step...assembly 5 Replace the high-voltage PCB 2. Is YES the problem corrected? Is the upper fusing cover securely ...Connect them securely. End. Replace the dc controller PCB. EN Copy module troubleshooting 489
  • HP 8550 | Service Manual - Page 492
    The copy has an image covered with dots Unit Printer Cause Step Checks Yes/No Action Replace .... The copy has a (positive) ghost image Unit Printer Cause Step Checks Are connector J681 on the .../ dc controller PCB YES NO End Replace the dc controller PCB. 490 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 493
    ... in double-sided copying mode) Unit Printer Cause Step Checks Is the duplexing feeding roller 1 soiled? Is the feeding guide soiled? Is the ... brush. Is the problem corrected? Are the contacts of the CCD/ CCD driver corrections correct? YES End. 8 YES End. EN Copy module troubleshooting 491
  • HP 8550 | Service Manual - Page 494
    9 Replace the CCD/CCD driver. NO Is the problem corrected? Check to find out if the connectors on the AP-IP PCB are connected securely; if normal, replace the AP-IP PCB. 492 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 495
    ... module LCD at the time they occur. A history of errors can be reviewed through the copy module service mode (COPIER > DISPLAY > ERR). See "Service mode" on page 60. Note Errors described as "printer" or "printer unit" will also appear as error messages on the printer's LCD....
  • HP 8550 | Service Manual - Page 496
    ... out JP201 on the dc controller PCB to discharge C259; see the Printer Unit Service Manual.) E001 (printer) The fusing assembly has overheated. This error occurs .... (Short out JP201 on the dc controller PCB to discharge C259; see the Printer Unit Service Manual.) 494 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 497
    ... securely? Replace the power supply of the printer unit. Is the problem corrected? YES NO Check ... if problem parts are found. Connect the connectors securely. 3 Power supply (printer unit)...Check the product number of the fuser assembly; if necessary, replace the fusing assembly or the printer unit ...
  • HP 8550 | Service Manual - Page 498
    ... motor 2 E013 (printer) A specific number of copies have been made after the waste toner ... case Step 1 Checks Is the photosensitive drum cartridge full of waste toner? Y/N YES NO Action Replace the photosensitive drum cartridge. Replace the dc controller PCB. 496 Chapter 7 - Troubleshooting ...
  • HP 8550 | Service Manual - Page 499
    ... power-on or while the drum motor is rotating during printer operation, the light-receiving cell of the waste toner sensor does not ... with a dry cloth. 4 Replace the waste toner detection YES block of the printer unit. Is the NO problem corrected? End. Replace the photosensitive drum unit. If the ...
  • HP 8550 | Service Manual - Page 500
    E020 (printer) During image stabilization correction control, the LED intensity signal (LEDCNT)...PCB. Replace the dc controller PCB. E021 (printer) This error occurs when the developing rotary position... open properly when in its proper position in the printer? Close the toner cartridge cover, and turn...
  • HP 8550 | Service Manual - Page 501
    ... Developing rotary stopper 5 Replace the developing rotary position sensor. Is the problem corrected? YES End. 6 Is the operation of the developing NO rotary stopper ... control device goes to zero (0) when the open circuit detection mechanism is not disabled. EN Copy module troubleshooting 499
  • HP 8550 | Service Manual - Page 502
    E040 (printer) The holding plat lifter (multi-feeder) is faulty. This error occurs during multi-feeder pick... PCB; connectors J641, J642, J643, and J647 on the printer side main relay PCB; connectors J671 and ... PCB. +24 UH 3 See "No +24 UH (printer)" on page 523. Replace the holding plate solenoid. ...
  • HP 8550 | Service Manual - Page 503
    .... Connect the connectors securely. Replace the sensor. Duplexing driver 3 PCB Duplexing feeding roller 1 home ..., J2004, and NO J2007 on the duplexing driver PCB connected securely? Replace the duplexing ... the duplexing motor (M8). Replace the duplexing driver PCB. EN Copy module troubleshooting 501
  • HP 8550 | Service Manual - Page 504
    E055 (printer) The duplexing driver PCB has detected that the horizontal registration guide has ...2 Replace the lever. 3 Horizontal registration guide drive gear Duplexing driver 4 PCB Horizontal registration ... motor (M7). Replace the duplexing driver PCB. E066 (printer) During image stabilization ...
  • HP 8550 | Service Manual - Page 505
    ... Action Connect the connectors securely. Connector (laser 1 driver signal line) Connectors (BD 2 line) Are connector J1001 on the laser NO driver PCB and connector J205 on the dc controller ... unit. Replace the dc controller PCB. E110 (printer) This error occurs when the scanner motor fails ...
  • HP 8550 | Service Manual - Page 506
    ...the reader controller PCB to J303 and J302 on the scanner motor driver PCB? Replace the scanner motor driver YES PCB. Is the problem corrected? Replace the scanner motor (PM1). YES Is the problem corrected? NO Scanner motor driver PCB Scanner motor (PM1) 4 5 End. End. Replace the...
  • HP 8550 | Service Manual - Page 507
    E203 The scanner motor driver PCB or the scanner motor is faulty. This error occurs when the scanner home ...motor. Replace the reader controller PCB. Scanner motor driver PCB/ Scanner motor Reader controller PCB 2... between connectors J303-B1 (RST) on the scanner motor driver PCB and J303-B4 (GND) and...
  • HP 8550 | Service Manual - Page 508
    ... controller PCB Step 1 2 Checks Replace the fluorescent lamp. Is the problem corrected? Replace the inverter PCB.... Step Checks Replace the lamp heater. Is the problem corrected? Yes/No Action YES ... the reader controller PCB. 1 Lamp heater, reader controller PCB 506 Chapter 7 - Troubleshooting ...
  • HP 8550 | Service Manual - Page 509
    ... the scanning lamp, be sure to execute intensity adjustment in service mode (FUNCTION > MISC-R > USE-LAMP). If you ... to execute intensity adjustment and CCD adjustment in service mode (FUNCTION > MISC-R > LAMP-ADJ and FUNCTION > CCD > CCD-ADJ, respectively.) Note EN Copy module troubleshooting 507
  • HP 8550 | Service Manual - Page 510
    ...the interface cable used to connect the copy module and the printer unit connected securely? Further, are the copy module power cord and the printer unit power cord connected securely? Yes/No Action ... unit off and remove the formatter, and turn on the printer YES unit and copy module as one...
  • HP 8550 | Service Manual - Page 511
    ... the copy module using OPTION > USER > SERIAL in service mode. E401 The error shown on the touch-screen display is in the ADF. See "ADF troubleshooting" on page 528. This error indicates that either the ... on and off two times or more within one second. EN Copy module troubleshooting 509
  • HP 8550 | Service Manual - Page 512
    ...The error shown on the touch-screen display is in the ADF. See "ADF troubleshooting" on page 528. This error indicates that either the belt motor (M3) ...The error shown on the touch-screen display is in the ADF. See "ADF troubleshooting" on page 528. This error indicates that either the ADF motor (M2)...
  • HP 8550 | Service Manual - Page 513
    ...screen display is in the output device. Note Output devices are not supported on the LJ8550 MFP. This error indicates that the bin flapper 1 (for E545) or bin ... power cables of the accessories and the YES communication cable to the printer unit connected securely? EN Copy module troubleshooting 511
  • HP 8550 | Service Manual - Page 514
    ... copy module) 2 YES NO End. Refer to the Service Manual for the reader-unit accessory in question. ... set COPIER > OPTION > INT-FACE > B-CLR in service mode to "0", and then disconnect the copy .... Note The copy data controller is not available for the LJ8550 MFP. 512 Chapter 7 - Troubleshooting ...
  • HP 8550 | Service Manual - Page 515
    E805 (printer) The heat discharge fan 1 (FM, used for the fusing assembly and area near the feeding assembly) is faulty. This ...the main relay PCB. The dc power 65 NO YES See "No dc power in the printer (+5V, +24 VB)" on page 522. Replace the dc controller PCB. EN Copy module troubleshooting 513
  • HP 8550 | Service Manual - Page 516
    E806 (printer) The heat discharge fan 2 (FM2, used for the area around the intermediate transfer drum) ... after the copier is turned on? Is the dc power present in the printer unit? NO YES Connect the connectors securely.... Replace the main relay PCB. The dc power (printer unit) 6 See "No dc power ...
  • HP 8550 | Service Manual - Page 517
    ... and lower fusing heaters. Cause Fusing assembly Power supply (printer unit) Step 1 2 Checks Replace the fusing assembly. Is the problem corrected? Replace the power supply on the printer side. Is the problem corrected? (The fusing heater drive circuit or the fusing...
  • HP 8550 | Service Manual - Page 518
    E809 (printer) The power supply cooling fan (FM4, used for the area around the copy module main power .... Connect the connectors securely. YES Check the drum cartridge switching lever on the printer side. Is it displaced or cracked? Is the drum cartridge switching guide defective? Are connector J209 ...
  • HP 8550 | Service Manual - Page 519
    E812 (printer) This error occurs when the intermediate transfer drum (ITD) home position is not ... sensor Step 1 Checks Is the intermediate transfer drum (ITD) set in the printer properly? Y/N NO YES.... Replace the drum cartridge. Is the YES problem corrected? NO EN Copy module troubleshooting 517
  • HP 8550 | Service Manual - Page 520
    ... touch-screen display is in the side HCI. See "Side HCI troubleshooting" on page 535. This error indicates one of three problems: 1 2 3 An error has been ...timing problem has occurred with the copy module. Power cycle the unit to alleviate the problem. 518 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 521
    ... Connect the power plug. Advise the user to correct the problem. Go to step 7. Check the ac power ... Replace the power cord or the noise filter PCB. Is the problem corrected? YES NO Connect the probes to... circuits even if there is no fault in the leakage breaker. EN Copy module troubleshooting 519
  • HP 8550 | Service Manual - Page 522
    ... the power plug. After three minutes, connect the power plug to the power outlet, and turn on the copy module power switch. Does the copier operate normally? NO 2 Overcurrent/ overvoltage (protection circuit activation), copy module main power supply PCB 520 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 523
    ... supply YES switch. Is the resistance 0Ω when the printer power switch is on and ∞Ω when the switch is off... power switch (SW1), printer power supply 3 Note After turning off the circuit... and continuity) with a meter. At the time of installation, the printer power switch (SW1) is turned on and...
  • HP 8550 | Service Manual - Page 524
    ... Cause Step Checks Disconnect the power plug from the printer and connect it directly to the power outlet. ... copy module power plug and turn on the printer power switch (SW1). Is the operation NO normal...J204 from YES the dc controller PCB. Connect the printer's power plug directly to the power outlet ...
  • HP 8550 | Service Manual - Page 525
    ... dc power 1 Disconnect the power plug of the YES printer from copy module and connect it directly to the... (GND). Is it 24 V? Disconnect the power plug of the NO printer from the copy module, and YES then connect it directly to the power outlet. Turn on the printer power switch (see note on page 521)...
  • HP 8550 | Service Manual - Page 526
    ... dc power 1 Disconnect the power plug of the YES printer from copy module and connect it directly ... relay PCB when the drum cartridge switch (SW642) is turned on? Disconnect the power plug of the NO printer ...) 5 Replace the toner cartridge cover switch (SW762) on the sub-relay PCB. Drum cartridge ...
  • HP 8550 | Service Manual - Page 527
    ... sensor (PS101) normal? See the instructions for how to check the photo-interrupters. Are connector J301 on the scanner motor driver PCB and connectors J3, J5, ... power to the copy module" on page 520. Scanner motor driver PCB Scanner motor (PM1) End. Replace the scanner ...
  • HP 8550 | Service Manual - Page 528
    ... capacity after removing the cause. (To do so, short out JP201 on the dc controller PCB; for details, see the Printer Unit Service Manual). Select DISPLAY > ERR to check the error history. l 526 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 529
    ... to part fault isolation The copy module can test the functionality of many of its parts from service mode. The list below shows the parts that can be ... the size detected. To check the home-position photointerrupter, select COPIER > DISPLAY > SENSOR > SC-HP. 6 EN Copy module troubleshooting 527
  • HP 8550 | Service Manual - Page 530
    ADF troubleshooting Fault isolation ADF service involves whole-unit exchange, but only after the following ... can also be performed from Service Mode on the copy module. These procedures are also documented in the ADF installation guide that ships with the new ADF. 528 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 531
    Numbered error codes Note If the table indicates replacement of a part, exchange the entire ADF. E401 This error indicates that either the pick-up motor (M1) does not ... PCB. If normal, replace the pick-up motor. Replace the DADF controller PCB. Pick-up motor (M1) 2 NO EN ADF troubleshooting 529
  • HP 8550 | Service Manual - Page 532
    ...on the DADF controller PCB. Does the reading change to 23 V when the Copy Start key is pressed? YES ADF motor (M2) 2 Check the wiring from the ADF motor (M2) to the DADF controller PCB. If normal, replace the ADF motor (M3). Replace the DADF controller PCB. NO 530 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 533
    ...levels of the document YES tray paper sensor and the registration sensor. is the problem corrected? Is the light-receiving section of YES each sensor soiled with paper...normal, replace the document tray paper sensor (S1) or the registration (light-receiving) sensor (LED3). EN ADF troubleshooting 531
  • HP 8550 | Service Manual - Page 534
    ...the ADF is receiving power from the printer. Turn the power switch off and then YES on. Is the problem corrected? Set the meter... DADF controller PCB. YES Is the problem corrected? NO Wiring 2 DADF controller 2 PCB End. Replace the printer's dc controller PCB. 532 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 535
    ... one of the numbered error messages in the copy module's LCD. CAUTION The copy module might reset itself (turning itself off and on) when the self-diagnosis begins. If the ADF is out of order, copies can still be made by placing originals on the copyboard glass. Note EN ADF troubleshooting 533
  • HP 8550 | Service Manual - Page 536
    ... up, and the voltage of TP2-1 and TP2-2 is 1.1±0.1 V. If the voltage of either TP1-1 or TP1-2 is not as indicated, suspect displacement of the light-emitting/-receiving unit of the sensor that corresponds to the meter probe. Check the position of the sensor. 534 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 537
    ...orange 2color light) on the LED PCB and the service LED (LED201: red light) on the deck driver PCB. These LEDs, used in combination with the DIP switches (SW201) on the paper deck driver PCB, will help to troubleshoot the side HCI effectively. 1 2 3 User LED Service LED DIP switch bank 2 1...
  • HP 8550 | Service Manual - Page 538
    User and service LEDs User LED The condition of the user LED (LED1) in the unit .... l l Continuous green light-the unit and the printer assembly are communicating normally. Flashing orange ... or in the factory default position for normal operation. Service LEDs The combination of DIP switch settings ...
  • HP 8550 | Service Manual - Page 539
    ... the information in table 92 to identify errors based on the service LED lighting cycle. For example, if the service LED flashes twice in the header section, and once in the error detection section, this ... Upper right cover open, lifter being raised Out of paper EN Side HCI troubleshooting 537
  • HP 8550 | Service Manual - Page 540
    ... switch 2 (SW602) Run sensor or switch test 1 2 3 Turn off the HP Color LaserJet 8550 (use the power switch on the copy module). Remove the ...On 4 5 6 Pull the side HCI away from the printer. Open the upper right cover. Turn on the HP Color LaserJet 8550 (use power switch on the copy module). 538 ...
  • HP 8550 | Service Manual - Page 541
    ... the system off. Connect a C-link cable between the printer and side HCI. Remove the rear cover.... switch so that the side HCI reads that it is attached to the printer. Note The side HCI interlock switch is ...the Deck Set Detection Switch. 6 Load paper in the side HCI. Side HCI troubleshooting 539 EN
  • HP 8550 | Service Manual - Page 542
    ... continuously until the paper runs out or the test is terminated. The pick-up mode can be interrupted by turning off SW201-1. The test pick-up can be resumed by setting SW201-1 to ON. When testing with the pick-up mode is complete, turn off all DIP switches. 540 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 543
    ... Cause Poor interface between side HCI and printer (C-link interface) Defective power switch Step 1 ..., dc load, deck controller PCB 4 Turn off the printer assembly power switch and disconnect connector J203... connector put out the measured dc power supply? NO YES EN Side HCI troubleshooting 541
  • HP 8550 | Service Manual - Page 544
    ...? Can the error condition be remedied by replacing the pick-up motor? Can the error condition be remedied by replacing the deck controller PCB? Y/N NO Action Correct the connection. 2 YES Replace the pick-up motor. 3 YES Replace the deck controller PCB. 542 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 545
    ...gears and springs. Are there any worn or damaged parts? Are there any loose springs? Are connector J210 ... roller at the same time. Replace worn or damaged parts. Correct springs. 2 YES Poor contact in... Correct spring position. Replace the feed paper sensor. 3 YES EN Side HCI troubleshooting 543
  • HP 8550 | Service Manual - Page 546
    ...check drive gears and springs. Are there any worn or damaged parts? Are there any loose parts? Are connector J205 and relay connector J302 on the paper deck drive printed circuit ... defective? Y/N YES Action Replace rollers if they are worn or defective. 544 Chapter 7 - Troubleshooting EN...
  • HP 8550 | Service Manual - Page 547
    ...Y/N YES Action Replace damaged or defective feed guides. Skewed feed Cause Feed roller, ...dirt accumulated in the feed roller and separation roller guides? Are there any damaged or defective pick-up ...to remove dirt. 2 YES Replace any damaged or defective rollers. EN Side HCI troubleshooting 545
  • HP 8550 | Service Manual - Page 548
    546 Chapter 7 - Troubleshooting EN
  • HP 8550 | Service Manual - Page 549
    8 Parts and diagrams Chapter contents How to use this chapter...551 Printer parts unique to the HP Color LaserJet 8550MFP . . 552 Stand ...555 Screw/ring kit ...555 Stand assembly ...556 Copy module ...558 Screw/ring kit ...558...
  • HP 8550 | Service Manual - Page 550
    Motor driver PCA ...589 Inverter PCA ...590 Connectors ...591 ADF ...600 Belt kit ...... assembly...632 Belt drive motor assembly ...634 Upper paper guide assembly...636 Lower paper guide assembly......653 External covers and panels ...654 Internal components ...656 548 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 551
    Lifter drive assembly ...663 Paper pick-up assembly ...664 Deck controller PCA ...668 Connectors ...669 Numerical parts list ...672 Alphabetical parts list ...680 EN Chapter contents 549
  • HP 8550 | Service Manual - Page 552
    550 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 553
    ... only and will not be replaced in the field. These parts will not be available to order from HP. Parts that have a kit description instead of a .... All screws and fasteners may also be obtained locally. Because of HP's whole-unit exchange policy, ADF parts are listed for reference only. Except for the...
  • HP 8550 | Service Manual - Page 554
    Printer parts unique to the HP Color LaserJet 8550MFP 9 Figure 417. Interface assembly location Table 93. Interface assembly location Key 3 8 9 Part number FH2-6455-000CN FG2-9470-000CN FG6-3597-000CN Quantity 1 1 1 1 Description Connector, short (terminator) Dc controller PCB ...
  • HP 8550 | Service Manual - Page 555
    Figure 418. ECO-2 PCB Assembly Table 94. ECO-2 PCB Assembly Key 40 47 48 Part number Quantity 2 1 1 Description Screw, TP, M4X8 ECO-2 cable (J2101, J2102) ECO-2 PCB assembly (see Figure 419) EN Printer parts unique to the HP Color LaserJet 8550MFP 553
  • HP 8550 | Service Manual - Page 556
    ... 419. Interface assembly Table 95. Interface assembly Key 1 2 3 4 5 6 7 8 9 10 11 501 Part number Quantity 2 2 1 1 2 1 1 1 4 1 2 2 Description Screw, stepped Screw, M3X4 Interface PCB assembly ... head Screw with washer, M3X6 Clip, cable Screw, TP, M3X6 Shim 554 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 557
    Stand Screw/ring kit Table 96. Stand screw/ring kit Part number C7838-67901 Quantity 1 kit 1 2 8 4 2 2 8 8 4 8 8 4 Description Stand screw/ring kit Screw, M6X6 Screw, M6X6 Screw, Allen head, M8X8 Screw, M4X8 Ring, E Washer, plain Screw, TP, M4X8 Ring, E Washer, plain Washer, spring Screw, allen ...
  • HP 8550 | Service Manual - Page 558
    Stand assembly Figure 420. Stand assembly 556 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 559
    ...-000CN XG9-0304-000CN Stand screw/ring kit XZ9-0446-000CN XZ9-0457-000CN Stand screw/ring kit XZ9-0367-000CN XZ9-0491-000CN FB4-2689-000CN XZ9-0491-000CN FB4-2689-000CN XZ9-0491-000CN Part number Stand screw/ring kit Stand screw/ring kit Quantity 1 2 1 2 1 1 1 1 2 1 1 1 1 8 2 2 1 4 4 4 2 2 2 2 1 1...
  • HP 8550 | Service Manual - Page 560
    Copy module Screw/ring kit Table 98. Screw/ring kit Part number C7836-67901 Quantity 1 kit 4 2 * 1 4 4 6 * 1 4 * * 2 2 2 * 2 8 1... truss head, M4X20 Screw, mach., truss head, M5X6 Screw with washer, M3X6 Screw, M3X8 Screw, mach., truss head, M3X6 *Several used 558 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 561
    Table 98. Screw/ring kit (continued) Part number Quantity 4 4 8 1 1 2 4 4 8 1 2 8 2 8 2 2 1 *Several used Description Screw with washer, M4X6 Screw, mach.,...head, M3X6 Screw with washer, M4X6 Belt kit Table 99. Belt kit Part number C7836-67902 Quantity 1 kit 1 Description Copy module belt kit Flat...
  • HP 8550 | Service Manual - Page 562
    Gear/pulley kit Table 100. Gear/pulley kit Part number C7836-67903 Quantity 1 kit 1 1 2 4 ... Pulley, tension Spring kit Table 101. Spring kit Part number C7836-67904 Quantity 1 kit 2 1 2 1..., leaf Spring, leaf Spring, tension Spring, tension Spring, compression 560 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 563
    Assembly location diagram Copyboard cover assembly (figure 428) Control panel inverter PCA (figure 436) Motor driver PCA (figure 439) Control panel assembly (figure 427) Control panel PCA (figure 434) Control panel CPU PCA (figure 435) Mirror assembly 1 (figure 429) APC power supply PCA (figure ...
  • HP 8550 | Service Manual - Page 564
    External covers and panels Control panel assembly (figure 427) Figure 422. External covers and panels 562 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 565
    ...8662-000CN FB5-5324-000CN FB5-5334-000CN FF6-0285-000CN FB5-5318-000CN FB5-5317-000CN FF6-0284-000CN Part number Quantity 1 1 1 1 1 2 1 1 2 1 1 1 1 1 1 2 1 1 1 1 4 1 1 1 1 1 1 1 7 2 1 1 1 1 1 1 1 1 2 * 1 Description Retainer, glass, right Cover, upper Cover, upper, front Cover, upper, rear Seal, ...
  • HP 8550 | Service Manual - Page 566
    Internal components Mirror assembly 1 (figure 429) Figure 423. Internal components (1 of 3) 564 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 567
    ... module gear/pulley kit Copy module spring kit Part number Quantity 3 1 4 2 1 1 1 1 1 1 1 4 1 2 1 1 2 1 1 1 1 1 4 4 1 2 1 4 6 * 1 4 * 3 * Description Screw, adjusting Pulley Damper Spring... 2 Pulley Mount, pulley, front Mount, pulley, rear Photo-interrupter, S7G37 (PS101 J2013) Plate, home position...
  • HP 8550 | Service Manual - Page 568
    Figure 424. Internal components (2 of 3) Table 104. Internal components (2 of 3) Key 1 2 *Several used Part number Copy module gear/pulley kit Quantity 2 1 Description Pulley, tension Sheet, protect, A 566 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 569
    ...module spring kit FB4-0752-000CN Part number Quantity 1 1 1 2 1 2 2 3 1 1 1 1 1 1 1 1 1 2 3 1 2 1 2 1 2 2 1 1 1 1 15 1 2 2 1 1 * 2 17 Description...) Core, ferrite Core, ferrite Motor driver power cable (J301, 2002) Motor driver signal cable (J303, 1605) Sheet, blanking Sensor, document size (A size...
  • HP 8550 | Service Manual - Page 570
    Figure 425. Internal components (3 of 3) 568 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 571
    ...000CN Copy module screw/ring kit Copy module spring kit Part number Quantity 4 1 1 1 1 1 1 1 1 1 1 1 1 2 1 7 9 3 1 1 28 * * 2 Description Plate, glass retaining Support, glass, right Connector, 2P (J2014) Spring, tension Nut Screw, stepped, M4...
  • HP 8550 | Service Manual - Page 572
    Power cord terminal assembly Noise filter PCA (figure 433) Figure 426. Power cord terminal assembly 570 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 573
    ... kit Copy module screw/ring kit Copy module screw/ring kit Copy module screw/ring kit Copy module screw/ring kit Part number Quantity 1 1 1 1 1 1 1 1 1 2 2 1 2 1 1 2 1 1 1 4 2 5 2 2 Description Cable, relay breaker (J1001) Sheet, protective Sheet, blanking Clip, cable Cover, power supply Relay, ...
  • HP 8550 | Service Manual - Page 574
    ... PCA (figure 434) Control panel PCA (figure 434) Control panel PCA (figure 434) Control panel PCA (figure 434) Control panel PCA (figure 434) Control panel inverter PCA (figure 436) Control panel CPU PCA (figure 435) Figure 427. Control panel assembly 572 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 575
    ...FB4-3142-000CN FB4-7871-000CN Part number FG6-5843-000CN Quantity ...M3X6 Screw, M3X8 Cover, lamp filter Support exposure light Key top, function,... Key top, 1 Cover, one-touch, 3 Support, right Plate, grounding Key top,... Sheet, insulating Key top, user guide Button, switch Spring, compression Function ...
  • HP 8550 | Service Manual - Page 576
    Copyboard cover assembly Figure 428. Copyboard cover assembly 574 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 577
    Table 108. Copyboard cover assembly Key 1 2 3 4 5 5A 6 7 8 501 502 Copy module screw/ring kit Copy module screw/ring kit FF9-1694-020CN Part number FG6-5851-000CN Quantity 1 2 2 1 1 1 3 2 2 3 4 8 Description Copyboard cover assembly Plate, reinforcement Hinge, copyboard cover Cover, copyboard, ...
  • HP 8550 | Service Manual - Page 578
    Mirror assembly 1 Figure 429. Mirror assembly 1 576 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 579
    ...000CN FB3-2411-000CN FB3-7692-000CN Part number FG5-9838-000CN Quantity 1... terminal, rear Plate, contact Cover, cable guide Pin, slide Pin, pad, 2 Flag, HP sensor Reflector, lower Reflector, auxiliary Reflector... rear Mount, sensor Mount, terminal, front Guide, cord Exposure filter Damper, 1 Damper, ...
  • HP 8550 | Service Manual - Page 580
    ... Inverter PCA (figure 440) Dc power supply PCA (figure 431) APC power supply PCA (figure 432) Power cord terminal assembly (figure 426) Reader controller PCA (figure 437) Analog image processor PCA (figure 438) Figure 430. Electrical tray assembly 578 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 581
    ... kit FG2-9539-000CN FH6-1463-000CN FH6-3844-000CN Part number Quantity 1 1 1 1 1 1 1 1 1 7 11 9 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 2 1 1 2 1 1 1 1 25 2 17 2 2 1 Description Sheet,... "Copy load" Connector, female (J2022) Cable, AC (J2, 1801) Support, PCB Screw, mach., truss head, M4X6 Ferrite clamp Core,...
  • HP 8550 | Service Manual - Page 582
    Dc power supply PCA Figure 431. Dc power supply PCA 580 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 583
    Table 111. Dc power supply PCA Key Part number FG5-9845-000CN FG5-9858-000CN CT1301 CT1301 FU1201 FU1201 FU1501 FU1502 FU1503 FU1504 FU1505 FU1506 FU1507 FU1508 FU1509 FU1511 FU1512 FU1513 FU1514 FU1515 FU1516 FU1517 FU1518 FU1519 L 1202 L 1202 L 1203 L 1203 L 1301 Q 1301 T 1201 T 1201 T 1301 T 1301...
  • HP 8550 | Service Manual - Page 584
    ... power supply PCA Figure 432. APC power supply PCA Table 112. APC power supply PCA Key Part number FG5-9847-000CN FG5-9861-000CN FU1801 FU1802 L 1801 T 1801 T 1802 ... V) Fuse, 60V, 10A Fuse, 60V, 1A Coil, choke Transformer (100/127 V) Transformer (220/240 V) 582 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 585
    Noise filter PCA Figure 433. Noise filter PCA Table 113. Noise filter PCA Key Part number FG2-9463-000CN FG2-9541-000CN 1 2 FU1101 FU2501 L 1101 L 2501 Quantity 1 1 1 1 1 1 1 1 Description Noise filter PCB assembly (100/127 V) Noise filter PCB assembly (220/240 V) Cable, noise filter, 1 Cable, ...
  • HP 8550 | Service Manual - Page 586
    ...Table 114. Control panel PCA Key 1 2 3 4 5 6 LED907 LED908 LED909 LED910 VR 941 Part number FG6-0366-000CN Quantity 1 1 1 1 1 1 1 1 1 1 1 1 ... LED unit LED unit LED unit Switch, VR * Control panel PCB assembly is included in the assembly shown in Figure 427. 584 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 587
    Control panel CPU PCA Figure 435. Control panel CPU PCA Table 115. Control panel CPU PCA Key 1 Part number FG6-0364-000CN Quantity 1 1 Description Control panel CPU PCB assembly* IC, MB89P637, M-PRO (Q919) * Control panel CPU PCB assembly is included in the assembly shown in Figure 427. EN ...
  • HP 8550 | Service Manual - Page 588
    ... panel inverter PCA Table 116. Control panel inverter PCA Key F1 T1 Part number FG9-3515-000CN Quantity 1 1 1 Description Control inverter PCB ... Transformer, inverter * Control panel inverter PCB assembly is included in the assembly shown in Figure 427. 586 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 589
    ... controller PCA Figure 437. Reader controller PCA Table 117. Reader controller PCA Key 1 1 1A 1A BAT1601 F 1601 F 1603 F 1604 IC1602 IC1604 IC1605 IC1608 IC1609 IC1610 Part number FG2-9443-060CN FG3-0215-000CN FG2-9448-080CN FG3-0220-000CN WK1-5019-000CN Quantity 1 1 1 1 1 1 1 1 1 1 1 1 1 1 ...
  • HP 8550 | Service Manual - Page 590
    ... PCA Table 118. Analog image processor PCA Key Q501 Q502 Q508 Q509 Q512 Q513 Q514 Part number FG3-0315-000CN Quantity 1 1 1 1 1 1 1 1 Description Analog ...C-MOS IC, KZ3S113831CFP, C-MOS IC, JSC05KR517AJ40, gate array IC, LF9008, ASIC IC, KZ3S157211CFP, C-MOS 588 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 591
    Motor driver PCA Figure 439. Motor driver PCA Table 119. Motor driver PCA Key Part number FG5-9842-000CN Quantity 1 Description Motor driver PCB assembly EN Copy module 589
  • HP 8550 | Service Manual - Page 592
    .... Inverter PCA Table 120. Inverter PCA Key FU1001 FU1002 L 1001 L 1002 T 1001 T 1002 T 1003 Part number FG5-9849-000CN Quantity 1 1 1 1 1 1 1 1 Description ... assembly Fuse, 60V, 4A Fuse, 60V, 1A Inductor Inductor Transformer Current transformer Transformer 590 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 593
    Connectors Figure 441. Connectors (1 of 3) Table 121. Connectors (1 of 3) Key J1 J1 J1 J2 J2 J2 J3 J3 J3 J4 J4 J4 J5 J5 J5 Quantity - 1 2 - 1 2 - 1 10 - 1 6 - 1 5 Description Dc power supply Connector, 9P, female Socket contact, 18-24AWG Dc power supply Connector, 5P, female Socket contact, 18-...
  • HP 8550 | Service Manual - Page 594
    ...female Connector, 4P, female Socket contact, 18-24AWG CCD driver Connector, 15P, female CCD driver Connector, 14P, female Optical motor driver Connector, 9P, female Socket contact, 18-24AWG Optical motor (PM1) Optical motor driver Optical motor driver Connector, 8P, female Connector, 8P,...
  • HP 8550 | Service Manual - Page 595
    Table 121. Connectors (1 of 3) (continued) Key J 904 J 905 J 905 J 909 J 909 J 921 J 921 J 922 J 922 J 931 J 931 J 941 J 941 J 951 J 951 J1001 J1001 J1001 J1002 J1002 J1003 J1003 J1003 J1101 J1101 J1101 J1601 J1601 J1602 J1602 J1604 J1604 J1605 J1605 J1605 J1605 J1606 J1606 Quantity 1 - 1 - 1 - 1 ...
  • HP 8550 | Service Manual - Page 596
    ... Connector, 2P, female Socket contact, 22-26AWG Reader controller Reader control DIMM To printer Connector stage unit Connector stage unit Connector, 11P, female Connector stage ... APC power supply Connector, 5P, female Socket contact, 18-24AWG APC power supply 594 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 597
    Table 121. Connectors (1 of 3) (continued) Key J1802 J1802 J1804 J1804 J2000 J2000 J2000 J2001 J2001 J2001 J2006 J2006 J2007 J2007 J2009 J2009 J2010 J2010 J2011 J2011 J2012 J2012 J2013 J2013 J2014 J2014 J2014 J2015 J2015 J2018 J2018 J2018 J2020 J2020 J2021 J2021 J2024 J2024 Quantity 1 6 - 1 1 1 4 ...
  • HP 8550 | Service Manual - Page 598
    ... Noise filter Connector, 9P, female Socket contact, 18-24AWG Cable, fluorescent Film, fluorescent Cable, fluorescent lamp Connector, 3P, female Pin contact, 22-28AWG Scanning lamp heater (H1) Cable, fluorescent lamp Connector, 13P, female Connector, snap tight 596 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 599
    Figure 442. Connectors (2 of 3) Table 122. Connectors (2 of 3) Key J2002 J2002 J2002 J2002 J2016 J2016 J2017 J2017 J2031 J2031 J2031 Quantity 1 1 9 9 2 1 2 1 - 1 1 Description Connector, 9P, male Connector, 9P, female Socket contact, 18-24AWG Pin contact Connector, 13P, female Connector, snap ...
  • HP 8550 | Service Manual - Page 600
    ... panel Connector, 15P, female Connector, 15P, female Holder, connector, 30P Control panel Connector, 2P, female Connector, 9P, male Connector, 9P, female Socket contact, 18-24AWG Pin contact Connector, 13P, female Connector, snap tight Connector, 15P, female 598 Chapter 8 - Parts and diagrams EN
  • HP 8550 | Service Manual - Page 601
    Table 123. Connectors (3 of 3) (continued) Key J2017 J2018 J2018 J2018 J2022 J2022 J2022 J2022 J2041 J2041 J2042 J2042 J2042 J2042 Quantity 1 1 1 4 - 1 1 3 2 1 1 1 1 2 Description Connector, snap tight Cable, fluorescent Connector, 5P, male Pin contact To document feeder Connector, female ...
  • HP 8550 | Service Manual - Page 602
    ADF Note The only part that can be serviced on the ADF is the large white feeding belt (... feeding belt" on page 431.) The remainder of the ADF will be serviced via adjustment/calibration (see "ADF adjustments... Belt kit Table 124. Belt kit Part number C7837-67903 2 2 2 1 1 1 1 1 1 1 1 1 FC2-1827-000CN...
  • HP 8550 | Service Manual - Page 603
    Bushing kit Table 125. Bushing kit Part number C7837-67904 1 3 1 2 2 2 1 1 2 1 Quantity Description ADF bushing kit Bushing Bushing...Bushing Bushing Gear/pulley kit Table 126. Gear/pulley kit Part number C7837-67905 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 Quantity Description ADF gear/pulley kit ...
  • HP 8550 | Service Manual - Page 604
    Pin kit Table 127. Pin kit Part number C7837-67902 1 2 6 1 6 1 1 1 1 1 2 Quantity Description ADF... kit Table 128. Screw/ring kit Part number C7837-67901 4 2 2 2 4 2 6 1 3 1 2 1 2 1 6 1 2 1 *Several used Quantity... Setscrew, M4X8 Screw, tapping, truss head, M4X6 602 Chapter - 8 Parts and diagrams ...
  • HP 8550 | Service Manual - Page 605
    Table 128. Screw/ring kit (continued) Part number Quantity 4 8 1 1 1 2 2 1 1 3 3 2 1 1 4 1 2 1 1 2 1 2 2 1 * 1 * 8 7 3 * 1 1 1 5 3 3 1 3 2 *Several used Description Screw, mach., truss head, M4X6 Screw, TP, M4X6 Screw, TP, M4X6 Screw, TP, M3X4 Screw, mach., truss head, M3X12 Screw, TP, M3X6 Screw, ...
  • HP 8550 | Service Manual - Page 606
    ... 128. Screw/ring kit (continued) Part number Quantity 3 3 2 1 4 1 2 1 2 8 1 1 1 *Several used Description ... kit Table 129. Spring kit Part number C7837-67906 1 4 6 2 4 6 1 2 1 2 1 1 2 1 1 4 2 Quantity Description ... Spring, tension Spring, tension Spring, tension 604 Chapter - 8 Parts and diagrams...
  • HP 8550 | Service Manual - Page 607
    ... assembly (figure 454) Paper feed motor assembly (figure 455) Upper paper guide assembly (figure 457) Paper separation assembly (figure 460) DF assembly (figure 447) Separation roller assembly (figure 459) Lower paper guide assembly (figure 458) RF assembly (1 of 4) (figure 450) Figure ...
  • HP 8550 | Service Manual - Page 608
    ... 130. Mounting hardware Key 1 2 3 4 5 6 7 8 9 10 501 502 503 Part number FB3-2141-000CN FB3-3143-020CN FB4-... Tray 3, copy Tray 2, copy Mount, tray Plate, tray Guide, paper right Screw, stepped, M3X1.4 Screw, mach.,... truss head, M4X30 Screw, TP, M4X6 Nut,hex,M5 606 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 609
    ... External covers and panels Table 131. External covers and panels Key 1 2 3 4 501 502 503 ADF screw/ring kit ADF screw/ring kit ADF screw/ring kit Part number FB5-5309-000CN FB5-5302-000CN FB5-5303-000CN Quantity 1 1 1 1 6 1 3 Description Cover, front Cover, upper Cover Plate, cover Screw, mach...
  • HP 8550 | Service Manual - Page 610
    DF assembly Figure 447. DF assembly 608 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 611
    ... kit FC1-1279-000CN ADF belt kit ADF belt kit FA3-4509-000CN Part number ADF screw/ring kit FM6-2145-000CN Quantity 1 1 1 1... joint paper pick-up Plate Crossmember, left Crossmember, center Crossmember, right Plate, guide, front Wire, grounding Screw, adjusting Mount, roller Shaft, feed belt Roller ...
  • HP 8550 | Service Manual - Page 612
    ... FE9-0117-000CN XG9-0237-000CN WC4-5030-000CN Part number ADF gear/pulley kit ADF spring kit ADF... Bracket, connector Clip, cable Microswitch (MS1) Spacer, PCB Guide, belt Grommet Bearing, ball Spacer, PCB Foot, ... Screw, TP, M4X6 Screw, TP, M4X6 Screw, TP, M3X4 610 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 613
    Table 132. DF assembly (continued) Key 513 514 515 516 517 518 Part number ADF screw/ring kit ADF pin kit ADF screw/ring kit ADF screw/ring kit ADF screw/ring kit ADF pin kit Quantity 1 6 2 1 1 1 Description Screw, mach., truss head, M3X12 Pin, dowel Screw, TP, M3X6 Washer, toothed lock Nut, hex,...
  • HP 8550 | Service Manual - Page 614
    Document tray assembly Figure 448. Document tray assembly 612 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 615
    ... FC1-6179-000CN ADF gear/pulley kit FF6-0277-000CN Part number FF6-0276-000CN Quantity 1 1 1 1 1 1... Tray, document Label, paper size Cover, rear, tray Guide, slide Base guide Tray, auxiliary Clamp, guide Gear, 16T Guide, slide, rear Plate Label, warning Motor, dc 6 V (M4 J102) Lever, recycle Mount,...
  • HP 8550 | Service Manual - Page 616
    Upper cover assembly Figure 449. Upper cover assembly 614 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 617
    ...11 12 13 13A 501 502 503 ADF screw/ring kit ADF screw/ring kit Part number FG6-5836-000CN Quantity 1 5 5 1 2 1 4 1 1 ..., static charge Spring, torsion Wire Roller Sensor connecting cable (J207,303) IC, TLP1242, photo-interrupter (S6 J303) Plate, sensor guard Sheet, guard Screw, tapping, truss head, ...
  • HP 8550 | Service Manual - Page 618
    RF assembly Lower paper guide assembly (figure 458) To Paper separation assembly (figure 460) Figure 450. RF assembly (1 of 4) 616 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 619
    ... kit FB4-6994-000CN Part number Quantity 2 1 1 1 4 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 5 3 1 2 2 2 1 4 2 1 Description Bushing Stopper, lower guide Guide A, inner Plate, reverse ... Disk, clock Holder, sensor registration Cover, sensor Guide, paper Plate, sensor, separation Plate, positioning ...
  • HP 8550 | Service Manual - Page 620
    ... kit ADF screw/ring kit ADF screw/ring kit Part number ADF belt kit Quantity 1 1 1 6 1 1 * * 17 3 * 1 Description Belt, timing, 140T Rail, guide Plate Pin, dowel Bushing Bushing Screw, mach., truss ...grip Ring, E Screw, mach., truss head, M4X4 *Several used 618 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 621
    EN ADF 619
  • HP 8550 | Service Manual - Page 622
    Paper separation assembly (figure 460) Paper separation assembly (figure 460), callout 13 Figure 451. RF assembly (2 of 4) 620 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 623
    ...FB3-5660-000CN FB3-5637-000CN Part number Quantity 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Description Arm, shutter ... assembly (S1 J203) LED, TLN119B Photo-transistor TPS616C Cover, sensor Sheet IC, TLP1241, photo-interrupter (S5 J206) Plate, pick-up Cover switch ...
  • HP 8550 | Service Manual - Page 624
    ... gear/pulley kit ADF gear/pulley kit ADF spring kit Part number ADF screw/ring kit ADF screw/ring kit ..., 44T Flange C Flange D Motor, dc 23 V (M1 J12) Guide, cable Screw, M2X12 Connector, 2P (J216, 217) ..., E Ring, E Pin, spring Screw, TP, M4X6 *Several used 622 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 625
    EN ADF 623
  • HP 8550 | Service Manual - Page 626
    Figure 452. RF assembly (3 of 4) 624 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 627
    ...-000CN FB3-5642-000CN FF5-5201-020CN Part number Quantity 1 1 1 1 2 2 8 1 1 1 1 2 1 1 1 1 1 1 1 1 1 1 1 3 1 1 2 2 2 1 2 3 2 1 2 1 1 Description Plate, lifting, cam Shaft, cam Crossmember, guide, upper Guide, front, separation Rubber Sheet, A Sheet, B Plate, tray...
  • HP 8550 | Service Manual - Page 628
    ... pin kit ADF screw/ring kit ADF screw/ring kit ADF screw/ring kit Part number Quantity 1 1 2 1 1 * * 17 * 3 1 1 5 3 3 Description Sponge, damper Collar 2, retaining Connector, 2P (... Pin, spring Ring, E Ring, E Screw, mach., truss head, M3X10 *Several used 626 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 629
    EN ADF 627
  • HP 8550 | Service Manual - Page 630
    Separation roller assembly (figure 459) Figure 453. RF assembly (4 of 4) 628 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 631
    ... kit ADF gear/pulley kit ADF screw/ring kit ADF pin kit ADF bushing kit ADF bushing kit ADF screw/ring kit ADF screw/ring kit ADF screw/ring kit ADF belt kit FF5-5191-000CN Part number FB3-5638-000CN FB3-5639-000CN FB4-6988-000CN Quantity 1 1 1 1 1 2 1 1 2 1 3 1 1 1 1 1 2 6 1 1 * 7 * Description ...
  • HP 8550 | Service Manual - Page 632
    Right paper delivery assembly Figure 454. Right paper delivery assembly 630 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 633
    ...WG8-5362-000CN FB4-6990-000CN Part number FG6-5838-000CN Quantity ... Right paper delivery assembly Guide, upper, delivery Guide, lower, delivery Roller..., 21T/pulley, 42T IC, TLP1241, photo-interrupter (S12 J306) Clamp, cable... delivery assembly does not include the part shown in key number 30. EN ADF...
  • HP 8550 | Service Manual - Page 634
    Paper feed motor assembly Figure 455. Paper feed motor assembly 632 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 635
    ...-000CN ADF gear/pulley kit ADF screw/ring kit Part number FG6-2173-000CN Quantity 1 1 1 1 ..., 3 Motor, dc 24 V (M2 J11) Pulley, 1 Pulley, 2 Photo-interrupter, GP1A34A1 (S9 J210) Belt, timing, 92T Washer... M4x8 2 Paper feed motor assembly does not include the part shown with key number 8. EN ADF 633
  • HP 8550 | Service Manual - Page 636
    Belt drive motor assembly Figure 456. Belt drive motor assembly 634 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 637
    ...-000CN ADF gear/pulley kit Part number Quantity 1 1 1 1 1 1 1 1 3 1 1 2 2 1 1 1 1 1 1 1 1 2 1 1 3 3 2 1 4 1 2 1 2 Description Mount, motor ... J6) Clutch, electromagnetic (CL1 J13) Photo-interrupter, GP1A34A1 (S10 J211) Bushing ... motor assembly does not include the part shown with key numbers 21, 22,...
  • HP 8550 | Service Manual - Page 638
    Upper paper guide assembly Figure 457. Upper paper guide assembly 636 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 639
    ...2 3 4 5 6 6A 7 8 501 502 ADF bushing kit ADF screw/ring kit Part number FG5-7273-000CN Quantity 1 1 1 1 1 1 1 1 1 1 1 2 Description Upper paper guide assembly Guide, upper Flapper, reverse Plate, flapper, mounting Arm, flapper Spring, torsion Guide, ...
  • HP 8550 | Service Manual - Page 640
    Lower paper guide assembly Figure 458. Lower paper guide assembly 638 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 641
    Table 143. Lower paper guide assembly Key 1 2 3 4 5 6 7 8 9 10 501 502 ADF screw/ring kit Part number FG6-5837-000CN Quantity 1 1 5 1 4 6 5 2 1 1 1 1 1 Description Lower paper guide assembly Guide, paper, lower Rod Plate, guide Spring, leaf, 1 Spring, ...
  • HP 8550 | Service Manual - Page 642
    Separation roller assembly Figure 459. Separation roller assembly 640 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 643
    ...ADF gear/pulley kit FB4-6991-000CN FF5-5207-000CN Part number FG6-2176-000CN Quantity 1 1 1 1 ... Separation roller assembly Gear, 8T Gear, 6T Arm, guide rear Damper Roller, separation Roller, 2 Roller, drive, 1 Roller, drive, 2 Gear, 25T Roller Arm, guide front Damper Ring, E Pin, dowel EN ADF 641
  • HP 8550 | Service Manual - Page 644
    Paper separation assembly From RF assembly (4 of 4) (figure 453) Figure 460. Paper separation assembly 642 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 645
    ... ADF screw/ring kit ADF screw/ring kit ADF pin kit ADF pin kit ADF spring kit FF5-5188-000CN ADF bushing kit ADF gear/pulley kit ADF gear/pulley kit ADF spring kit ADF belt kit Part number FG6-4442-000CN ADF belt kit Quantity 1 8 1 4 2 1 1 1 2 2 1 2 4 1 1 1 1 4 4 2 1 1 1 1 1 1 2 Description Paper...
  • HP 8550 | Service Manual - Page 646
    RDF controller PCA Figure 461. RDF controller PCA Table 146. RDF controller PCA Key 1 Part number FG2-9927-000CN Quantity 1 1 Description RDF controller PCB assembly IC, M27C1001-80XF1, EP-ROM (Q2) 644 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 647
    Connectors Figure 462. Connectors (1 of 2) Table 147. Connectors (1 of 2) Key J1 J1 J1 J2 J2 J2 J3 J3 J3 J5 J5 J5 J6 J6 J7 J7 J8 1 13 1 2 1 4 1 7 Quantity Description RDF controller Connector, 7P, female Terminal RDF controller Connector, 4P, female Socket, contact, 18-24AWG RDF controller ...
  • HP 8550 | Service Manual - Page 648
    ...2P,female Connector, 2P Connector, 4P, female Connector, 4P Paper pick-up roller sensor (S5) Connector, 3P Connector, 3P Connector, 3P Connector, 3P, female Connector, snap tight Connector, 3P, female Connector, 3P Feeder motor clock sensor (S9) Connector, 3P 646 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 649
    Table 147. Connectors (1 of 2) (continued) Key J211 J211 J212 J212 J215 J215 J216 J216 J216 J217 J217 J217 J219 J219 J220 J220 J220 J221 J221 J306 J306 J307 J307 J307 J308 J308 1 1 2 1 1 1 2 1 1 1 2 1 1 1 1 1 2 1 Quantity Description Belt motor clock sensor (S10) Connector, 3P, female Connector, ...
  • HP 8550 | Service Manual - Page 650
    ..., 4P, female Connector, 4P Upper cover sensor (S4) Connector, 3P Connector, 3P Connector, 3P Connector, 2P, female Pin assembly, 2P Contact Delivery sensor 1 (S6) Connector, 3P Paper pick-up sensor (S7) Connector, 3P Reversing sensor (S8) Connector, 3P 648 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 651
    Side HCI Bushing kit Table 149. Bushing kit Part number C7839-67902 2 2 2 2 1 8 1 Quantity Description Side HCI bushing kit Bushing ... Bushing Bushing Bushing Gear/pulley kit Table 150. Gear/pulley kit Part number C7839-67903 1 1 1 2 1 1 1 1 1 1 1 Quantity Description Side HCI gear/pulley kit ...
  • HP 8550 | Service Manual - Page 652
    Screw/ring kit Table 151. Screw/ring kit Part number C7839-67901 2 4 2 2 4 2 * 2 * 2 3 2 * * 5 2 * 1 1 8 3 6 * 1 2 8 8 4 8 2 XD3-1200-122CN XD3-2200-102CN XD3-2200-122CN *Several used ..., E Screw, w/washer, M3X6 Ring, E Ring, E Pin, spring Pin, dowel Pin, dowel 650 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 653
    Spring kit Table 152. Spring kit Part number C7839-67904 1 1 1 1 2 1 1 1 1 1 Quantity Description Side HCI spring kit Spring, tension Spring, tension Spring, compression Spring, compression Spring, compression Spring, tension Spring, tension Spring, tension Spring, tension Spring, tension EN ...
  • HP 8550 | Service Manual - Page 654
    Assembly locations Lifter drive assembly (figure 470) Deck controller PCA (figure 473) Paper pick-up assembly (1 of 2) (figure 471) Figure 464. Assembly locations 652 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 655
    Mounting hardware Figure 465. Mounting hardware Table 153. Mounting hardware Key 1 2 501 Part number Quantity 1 2 8 Description Plate, mount Plate, latch Screw, TP, M4X4 EN Side HCI 653
  • HP 8550 | Service Manual - Page 656
    External covers and panels Figure 466. External covers and panels 654 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 657
    .../ring kit FB4-7381-000CN FF5-9141-000CN Part number FB4-7441-000CN FF5-9140-000CN Quantity... Panel, front Panel, upper Guide, LED Size plate Plate, shaft support Shaft, cover Cover, window Spring, torsion Tape, door cover Deck cover IC, TLP1241, photo-interrupter (PS2 J310) Screw, M4X6 Flag, sensor ...
  • HP 8550 | Service Manual - Page 658
    Internal components Deck controller PCA (figure 473) Lifter drive assembly (figure 470) Figure 467. Internal components (1 of 3) 656 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 659
    ...-2166-000CN FB4-7387-000CN Side HCI spring kit Part number Quantity 1 1 1 2 1 1 1 1 2 1 2 1 1 1 1 1 1 1 1 1 * 1 1 1 2 2 3 * 2 3 Description Label, adjusting Plate, pin holder ...positioning Arm, paper sensor Spring, tension Pin, positioning Pin, guide, 2 Roller Gear, 28T/41T Gear, 58T Paper sensing ...
  • HP 8550 | Service Manual - Page 660
    Figure 468. Internal components (2 of 3) 658 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 661
    ...screw/ring kit FG6-3921-000CN Part number RB1-6872-000CN FB4-...small Coupler, standard Screw, M4X10 Side guide plate, rear Plate, paper holder ... Holder, cable, rear Flange, idler Plate, pulley support, front Plate, pulley support, rear Pulley, lifting Flange, lifter Bushing Pulley, idler Shaft, lifter...
  • HP 8550 | Service Manual - Page 662
    Figure 469. Internal components (3 of 3) 660 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 663
    ...FB4-7424-000CN FF5-9122-000CN Part number FB3-9198-000CN FB4...-000CN Quantity 1 1 1 1 1 1 1 1 1 1 1 1 1 2 * 1 2 2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Description Handle, upper guide Latch, front Shaft, latch Lever..., releasing Spring, compression IC, TLP1241, photo-interrupter (PS1 J309) Spring, leaf...
  • HP 8550 | Service Manual - Page 664
    ... screw/ring kit Side HCI screw/ring kit Side HCI screw/ring kit XZ9-0459-000CN XA9-1109-000CN Part number RG5-4199-000CN Quantity 1 1 1 1 1 2 2 1 8 3 5 6 * 1... truss head, M2.3X10 Ring, E Ring, E Screw, TP, M4X4 Screw, tapping, truss head, M4X6 *Several used 662 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 665
    ...drive assembly Figure 470. Lifter drive assembly Table 158. Lifter drive assembly Key 1 2 3 4 5 501 502 Side HCI screw/ring kit Side HCI screw/ring kit Part number FG6-3919-000CN Quantity 1 1 1 1 1 2 1 2 Description Lifter drive assembly Gear, 65T/17T (SPM1 J205) Motor, stepping Gear, 20T/63T ...
  • HP 8550 | Service Manual - Page 666
    Paper pick-up assembly Figure 471. Paper pick-up assembly (1 of 2) 664 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 667
    ...gear/pulley kit Side HCI gear/pulley kit Part number FG6-3922-000CN Quantity 1 1 ...4 Description Paper pick-up assembly Crossmember, lower guide Guide, sensor Lever, release Lever, pick-up..., registration sensor Bushing Spring, tension IC, TLP1241, photo-interrupter (PS5 J314) Spring, tension Ring, E...
  • HP 8550 | Service Manual - Page 668
    Figure 472. Paper pick-up assembly (2 of 2) 666 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 669
    ...000CN RB2-2475-000CN FF5-9129-000CN Side HCI gear/pulley kit RB1-6588-000CN Part number FB4-7348-000CN FB4-7421-000CN FB4-7347-000CN Quantity 1 1 1... compression Spring, tension Gear, 14T/42T/32T Gear, 47T Gear, 35T IC, TLP1241, photo-interrupter (PS3,4 J312, 313) Cable, pick-up (J311-314, 317-320) ...
  • HP 8550 | Service Manual - Page 670
    Deck controller PCA Figure 473. Deck controller PCA Table 161. Deck controller PCA Key FU201 FU202 FU203 Part number FG2-9550-000CN Quantity 1 1 1 1 Description Deck controller PCB assembly Fuse, 60V, 1A Fuse, 60V, 1.25A Fuse, 60V, 1A 668 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 671
    Connectors Figure 474. Connectors Table 162. Connectors Key J201 J201 J203 J203 J203 J204 J204 J205 J205 J206 J206 J207 J207 J208 J209 1 1 1 1 6 Quantity Description To option controller Deck controller Deck controller Connector, 6P, female Socket contact, 18-24AWG Deck controller Connector, 5P, ...
  • HP 8550 | Service Manual - Page 672
    ... Connector, 3P Paper high sensor (PS4) Connector, 3P Door open sensor (PS5) Connector, 3P Pick-up motor 1 (SPM2) Connector, 5P, female Connector, 5P Connector, 5P, female Connector, 4P, female Connector, 2P, female Pick-up motor 2 (SPM3) Connector, 4P, female 670 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 673
    Table 162. Connectors (continued) Key J319 J320 J320 J320 J321 J321 J322 J323 J323 J324 J324 J325 J326 J326 J326 J327 J327 J327 J328 J328 J328 J601 J601 J901 J901 J901 1 6 1 1 2 1 2 1 2 1 1 1 1 1 1 1 1 1 1 Quantity 1 Description Connector, 4P Pick-up solenoid (SL1) Connector, 2P, female Connector, ...
  • HP 8550 | Service Manual - Page 674
    Numerical parts list Table 163. Numerical parts list Part number Description ADF paper separation belt kit ..., idler Flange, lifter Bushing Bushing Cover, lamp filter Support exposure light Pulley, lifting Tray 3, copy Pin, ... 18 16 17 13 11 12 15 1 11A 4 2 22 13 672 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 675
    Table 163. Numerical parts list (continued) Part number FB3-5639-000CN FB3-... left Hinge, right Pin, pad, 2 Handle, upper guide Plate, rail Wire, scanner, front Wire,...1 Key top, standby Key top, user guide Shaft, roller Cover, mount plate Cap,... 26 28 6A 9 3C 4C 13 29 8 27 3 EN Numerical parts list 673
  • HP 8550 | Service Manual - Page 676
    Table 163. Numerical parts list (continued) Part number FB4-6991-000CN FB4-6994-000CN FB4-..., dc controller Key top, function, 3 Cover, rear, tray Guide, slide Base guide Tray, auxiliary Cover, upper Cover Cover, ...9 8 9 7 28 8 1 14 15 14 2 3 4 5 2 3 1 23 14 21 3 674 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 677
    Table 163. Numerical parts list (continued) Part number FB5-5318-000CN ... rear Cover, upper, small Cover, rubber Guide, paper right Cover, power supply ...Roller, pick-up Plate, stop, woodruff Guide, front, separation Roller, separation Pillar,...8A 44 43 9 102 13 50 114 10 4 8 EN Numerical parts list 675
  • HP 8550 | Service Manual - Page 678
    Table 163. Numerical parts list (continued) Part number FF5-7815-000CN ... size) Mount, releasing Latch, rear Side guide plate, front Shaft, front Link,... Limit plate, separation Tray, document Guide, slide, rear Cover, upper, rear ...63 31 1 1A - 7 - - 54 30 62 - 1 1A - 676 Chapter - 8 Parts and diagrams...
  • HP 8550 | Service Manual - Page 679
    Table 163. Numerical parts list (continued) Part number FG5-7273-000CN FG5-9837-000CN ...-000CN Description Upper paper guide assembly CCD unit Mirror assembly 1 Mirror assembly 2 Motor driver PCB assembly Dc power supply PCB assembly (... 19 7 20 20 16 21 31 116 22 8 3 9 27 EN Numerical parts list 677
  • HP 8550 | Service Manual - Page 680
    Table 163. Numerical parts list (continued) Part number FH7-4559-000CN FH7... Relay, AC 250 V (RL1) Switch, main (MSW1) Photo-interrupter, GP1A34A1 (S10 J211)...Photo-interrupter (PS102 J2007) IC, TLP1225, photo-interrupter (S11 J215) IC, TLP1225,...26 28 29 30 31 32 14 678 Chapter - 8 Parts and diagrams ...
  • HP 8550 | Service Manual - Page 681
    Table 163. Numerical parts list (continued) Part number RG5-4199-000CN ... J327) Microswitch (MS3 J328) Microswitch (MS1) Photo-interrupter, SG206 (S4,7 J214, 304) ...photo-interrupter (S12 J306) IC, TLP1241, photo-interrupter (S5 J206) Battery,lithium,...16 15 6C 6D 41 3D 4D 5C EN Numerical parts list 679
  • HP 8550 | Service Manual - Page 682
    ... parts list Table 164. Alphabetical parts list Description ADF belt kit ADF bushing ...side Arm, flapper Arm, front Arm, guide front Arm, guide rear Arm, handle Arm... FG5-9847-000CN FG5-9861-000CN Part number C7837-67903 C7837-67904 C7837... 43 7 26 6 17 18 11 33 26 680 Chapter - 8 Parts and diagrams EN...
  • HP 8550 | Service Manual - Page 683
    Table 164. Alphabetical parts list (continued) Description Arm, roller Arm, shutter Band, roller Base guide Battery,lithium,CR2477-HE4H,3V Bearing... WK1-5019-000CN XG9-0304-000CN Part number RB2-2471-000CN Figure 471... 10 4 39 8 1 9 10 9 16 8 - 14 15 30A 1 19 8 EN Alphabetical parts list 681
  • HP 8550 | Service Manual - Page 684
    Table 164. Alphabetical parts list (continued) Description Bushing Bushing Bushing Bushing Bushing Bushing Bushing Bushing ... FH2-6464-000CN FG2-9539-000CN FB4-6703-000CN Part number ADF bushing kit ADF bushing kit ADF bushing... 6 4 29 32 11 26 17 20 7 16 12 1 2 682 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 685
    Table 164. Alphabetical parts list (continued) Description Cable, outlet Cable, pick-up (J311-314, 317-320) ...-2689-000CN FB5-5316-000CN FC1-1300-000CN RB2-2470-000CN Part number Figure 426 471-472 426 426 454 450-453 450-... L 1301 20 33 17 10 10 14 12 4 5 24 13 92 16A EN Alphabetical parts list 683
  • HP 8550 | Service Manual - Page 686
    Table 164. Alphabetical parts list (continued) Description Clamp, guide Clip, cable Clip, cable Clip, cable Clip, cable ... 217) FG5-9856-000CN FH7-5403-000CN Part number FC1-6179-000CN Figure 448 447 ... L 1202 L 1203 L 1801 115 2 20 25 3 120 684 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 687
    Table 164. Alphabetical parts list (continued) Description Connector, 2P (J220) Connector, ...J3) Cover, blanking, rear Cover, cable guide Cover, connector Cover, copyboard, front ...-9925-000CN FB5-5321-000CN 1 Part number Figure 454 424 424 ... 422 428 428 466 466 446 422 EN Alphabetical parts list 685
  • HP 8550 | Service Manual - Page 688
    Table 164. Alphabetical parts list (continued) Description Cover, function Cover, heater Cover, lamp filter Cover, ...-000CN FF6-0286-000CN FF6-0285-000CN FB2-4243-000CN Part number Figure 427 429 427 427 427 422 425 ... 5 6 15 9 14 1 16 T 1002 CT1301 15A 3 1A 3A 686 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 689
    Table 164. Alphabetical parts list (continued) Description Damper Damper, 1 Damper, 2 Dc power... core Film, fluorescent (J2015, 2037) Flag, HP sensor Flag, paper position Flag, ... FG2-9550-000CN FF5-9142-000CN Part number Figure 459 429 429 431...28 20 23 112 113 12 16 21 EN Alphabetical parts list 687
  • HP 8550 | Service Manual - Page 690
    Table 164. Alphabetical parts list (continued) Description Flapper, reverse Flat belt, timing, 100T ...XH9-0105-000CN FC1-3044-000CN FH6-0734-000CN Part number Figure 457 423 456 447 425 447 ...FU1503 FU1504 FU1519 FU1507 FU1001 FU1515 FU1511 FU1513 FU1509 FU1508 688 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 691
    Table 164. Alphabetical parts list (continued) Description Fuse, 8 A, 125 V (100/127 V)...inch/A size) Grommet Guide A, inner Guide B, inner Guide, belt Guide, cable ADF ...pulley kit ADF gear/pulley kit Part number Figure 433 431 471-...37 11 47 13 1 2 1 9 9 44 6 51 43 117 EN Alphabetical parts list 689
  • HP 8550 | Service Manual - Page 692
    ... 164. Alphabetical parts list (continued) Description Guide, cord Guide, front registration ..., LED Guide, lower, delivery Guide, paper Guide, paper right Guide, paper,...-5328-000CN FF5-5201-020CN Part number Figure 429 457 450... 29 3 IC1608 IC1604 IC1602 Q502 Q 1301 690 Chapter - 8 Parts and diagrams...
  • HP 8550 | Service Manual - Page 693
    Table 164. Alphabetical parts list (continued) Description IC, JSC05KR517AJ40, gate array IC, ... start Key top, stop Key top, user guide FB4-6988-000CN FB4-2585-000CN FB4...000CN WG8-5362-000CN WG8-5362-000CN Part number Figure 438 438 438 438 ...22 13 14 21 20 26 18 19 28 EN Alphabetical parts list 691
  • HP 8550 | Service Manual - Page 694
    Table 164. Alphabetical parts list (continued) Description Label, "Copy load" Label, "Legal Limitations" (...000CN FB4-7372-000CN FF5-9122-000CN FG6-0365-000CN Part number Figure 430 422 422 422 422 422 422 ... LED908 LED909 LED910 54A 4 16 21 10 4 4 4 10 51 3 27 692 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 695
    Table 164. Alphabetical parts list (continued) Description Lifter drive assembly Light ... J328) Mirror 1 Mirror assembly 1 Mirror assembly 2 Motor driver PCB assembly Motor ... power cable (J301, 2002) Motor driver signal cable (J303, 1605) Motor,...-0394-000CN FF5-9131-000CN Part number FG6-3919-000CN FG2...
  • HP 8550 | Service Manual - Page 696
    Table 164. Alphabetical parts list (continued) Description Mount, pulley, front Mount,...Mount, tray Mount, volume Mylar, registration guide front Noise filter PCB assembly ...FB4-7021-000CN FF5-9121-000CN Part number Figure 423 423 448 ...11 2 - 14 14B - 14C 10 18 5 20 694 Chapter - 8 Parts and diagrams...
  • HP 8550 | Service Manual - Page 697
    Table 164. Alphabetical parts list (continued) Description Photo-interrupter, SG206 (S4,7 J214..., dowel Pin, dowel Pin, dowel Pin, guide, 2 Pin, pad, 2 Pin, positioning Pin, ... pin kit Side HCI pin kit Part number WG8-5206-000CN Figure 450-... 13 8A 110 21 78 26 7 6 47 48 EN Alphabetical parts list 695
  • HP 8550 | Service Manual - Page 698
    Table 164. Alphabetical parts list (continued) Description Plate, clutch tensioning Plate, ... Plate, pressure pick-up Plate, pulley support, front FS6-8499-000CN FB4-7423-... FB4-0745-000CN FA3-9315-000CN Part number Figure 456 429 446 422... 12 7A 60 2 3 49 53 24 13 696 Chapter - 8 Parts and diagrams ...
  • HP 8550 | Service Manual - Page 699
    Table 164. Alphabetical parts list (continued) Description Plate, pulley support, rear Plate, rail Plate, reinforcement Plate, reinforcement, rear ... Plate, sensor guard Plate, sensor, separation Plate, shaft support Plate, shield Plate, shutter holding Plate, size index ...
  • HP 8550 | Service Manual - Page 700
    Table 164. Alphabetical parts list (continued) Description Pulley, lifting Pulley, roller, reverse Pulley, tension Rail, guide R-CON. extension DIMM assembly (Europe)...FG3-0215-000CN FG2-9443-060CN Part number FB2-8465-000CN ADF ...503 506 508 514 515 502 502 698 Chapter - 8 Parts and diagrams ...
  • HP 8550 | Service Manual - Page 701
    Table 164. Alphabetical parts list (continued) Description Ring, E Ring, E Ring, E Ring, E Ring, E Ring, ...XG9-0402-000CN ADF screw/ring kit ADF screw/ring kit Part number Side HCI screw/ring kit Side HCI screw/ring ...1 2 10 6 9 56 22 11 5 6 4 16 6 3 6 7 23 28 30 5 6 2C EN Alphabetical parts list 699
  • HP 8550 | Service Manual - Page 702
    Table 164. Alphabetical parts list (continued) Description Roller, front Roller, paper delivery Roller, pick-up ...kit ADF screw/ring kit Copy module screw/ring kit Part number FB3-5638-000CN FB3-5637-000CN FF5-5191-...12 11 17 9 6F 2 1 8 502 7 502 505 517 513 502 700 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 703
    Table 164. Alphabetical parts list (continued) Description Screw, mach., truss head, M3X3 Screw, mach., truss ..., mach., truss head,M4X6 Screw, mach., truss head,M4X6 Part number ADF screw/ring kit ADF screw/ring kit ADF ... 501 505 503 23 501 504 505 502 504 501 503 508 EN Alphabetical parts list 701
  • HP 8550 | Service Manual - Page 704
    Table 164. Alphabetical parts list (continued) Description Screw, mach., truss head,M4X6 Screw, mach., truss .../ring kit ADF screw/ring kit ADF screw/ring kit Part number Copy module screw/ring kit Copy module screw/... 501 501 502 501 502 503 502 503 502 502 506 702 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 705
    Table 164. Alphabetical parts list (continued) Description Screw, tapping, truss head, M4X8 Screw, TP, M3X4...kit Copy module screw/ring kit Side HCI screw/ring kit Part number Figure 449 447 450-453 423 456 447 424 ...503 504 501 508 503 504 18 9 503 505 505 5 23 12 502 EN Alphabetical parts list 703
  • HP 8550 | Service Manual - Page 706
    Table 164. Alphabetical parts list (continued) Description Screw, with washer, M4X6 Screw, with washer, M4X6 ...ring kit ADF screw/ring kit ADF screw/ring kit Part number Copy module screw/ring kit Copy module screw... 502 503 10 28 42 5 5 5 5 5 21 15 32 2B 3 6 19 704 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 707
    Table 164. Alphabetical parts list (continued) Description Shaft, paper sensor Shaft, pick-up release Shaft, ...-3246-000CN FB4-2675-000CN RB2-2512-000CN FB3-5642-000CN Part number Figure 471-472 471-472 471-472 450-453 471...8 13A 27 14 1 19 2 3 2 5A 7C 8 1B 1B 1C 1C 59 EN Alphabetical parts list 705
  • HP 8550 | Service Manual - Page 708
    Table 164. Alphabetical parts list (continued) Description Sheet, separation, leather Shutter Side guide plate, front Side guide plate, rear Side HCI ...-000CN FF5-9141-000CN FF5-9125-000CN FG6-3921-000CN C7839-67902 C7839-67903 Part number RB1-6872-000CN Figure 468 450-453 468 468 - - - - -...
  • HP 8550 | Service Manual - Page 709
    Table 164. Alphabetical parts list (continued) Description Spring, leaf Spring, leaf Spring, leaf Spring, leaf ...Side HCI spring kit Copy module spring kit FB4-7391-000CN Part number Figure 424 425 430 430 460 467 467 469 ...83 85 86 87 88 98 99 100 9 4 8 12 15 44 45 53 EN Alphabetical parts list 707
  • HP 8550 | Service Manual - Page 710
    Table 164. Alphabetical parts list (continued) Description Spring, tension Spring, tension... note1) Stand screw/ring kit Stopper, lower guide Support exposure light...-5669-000CN FB4-7425-000CN Part number Side HCI spring kit... T 1301 T 1801 T 1201 T 1301 T 1802 T1 2 1 708 Chapter - 8 Parts and diagrams...
  • HP 8550 | Service Manual - Page 711
    Table 164. Alphabetical parts list (continued) Description Tray cable assembly (J8,...assembly Upper cover assembly Upper paper guide assembly Washer Washer, plain Washer,...FB5-5296-000CN FF6-0276-000CN Part number Figure 448 448 448... 516 504 503 502 7 42 41 9 9 18 8 6 7 EN Alphabetical parts list 709...
  • HP 8550 | Service Manual - Page 712
    710 Chapter - 8 Parts and diagrams EN
  • HP 8550 | Service Manual - Page 713
    ... absorption, chromatic 221 ac power troubleshooting 519 accessories connection status 66 information from HP FIRST 43 ordering 39, 44 accessories power supply ...238, 239 ACC-STS menu 66 acronyms guide 103 ACS (color auto recognition) area adjustments 89 defined 51 ACS key 50 ...
  • HP 8550 | Service Manual - Page 714
    ... timing 89 CMYK balance 86 CMYK density 85, 109 color area 89 control panel contrast 49 document tray paper ...-through mode 213 AP-IP PCB functions 206 removing 372 replacing 134 application notes HP Driver Distribution Center 44 HP FIRST 43 applying lubricants 174 arching, during paper feed 258 arms,...
  • HP 8550 | Service Manual - Page 715
    ... roller assembly 640 servicing 377 sheet-to-sheet gap, adjusting 149 side guide lock, removing ..., theory of operation 204 cancellation, theory of 213 colored, adjusting for 121, 205 omission mode 213 ... settings 62 bands, part numbers 681 bank note detection function overview 231 troubleshooting 480 ...
  • HP 8550 | Service Manual - Page 716
    ... density adjust 53 black toner, creating 219 black, solid troubleshooting 480 BLANK ...-capacity input (HCI) 304 blocks color correction 212 image processor 206 output 201 transfer 201 boards, PS/PCL 508 body cover (ADF)... device) calibration 128 cleaning 166 color correction, theory of 212 diagrams 27 ...
  • HP 8550 | Service Manual - Page 717
    ...correction, theory of 208 theory of operation 201 CCD driver, theory of operation 202 CCD menu adjust mode... slip stop 393 timing, adjusting 89 CMYK color balance 86 density, adjusting 85, 109 ...70 series 70 coils, part numbers 684 cold reset 57 color auto gradation adjustments 125 background, adjusting...
  • HP 8550 | Service Manual - Page 718
    color correction CCD settings 94 color balance, CMYK 86 displacement 471 offset ... options 110, 466 theory of 212 COLOR menu 86 communications automatic document ... (HCI), part numbers 669 interface 33 power supply cord 26 printer ... period toner 177 COPIER screen 60 copy module ac power, troubleshooting ...
  • HP 8550 | Service Manual - Page 719
    ... main power supply 239 motor driver 589 noise filter 583 operating ... parts 333 return to standard mode 139 scanner motor, removing 338 service..., 512 troubleshooting image faults 491 copy module controller PCB part numbers...-size identification 197, 199 part numbers 689 troubleshooting 462 copying status...
  • HP 8550 | Service Manual - Page 720
    ... 44 Dealer Response Line 44 HP ASAP (Automated Support Access Program) 42 HP ...44 HP FIRST (Fax Information Retrieval Support Technology) 43 HP Software Distribution Center 44 technical 42 websites 40 Customer Support Sales ... numbers 119 replacing 120 DC power, troubleshooting 520 DC-CON menu 79 Dealer...
  • HP 8550 | Service Manual - Page 721
    ... 101 size mix mechanism 115 disassembling printer 332 disconnecting flexible cable 355 ...touch panel clearing 55 diagrams 50 troubleshooting 458 distance, horizontal size plate ... 277, 278 pick-up motor 275, 276 Driver Distribution Center 44 driver PCB, scanner motor removing 339 drum cartridge faults ...
  • HP 8550 | Service Manual - Page 722
    ...Center (ECCC) 45 exchanging parts 41 exiting Power Save mode 49 Service Support Tool 139 exposure recalibration 56 exposure recalibration ... 163 removing 346, 375 Fax Information Retrieval Support Technology (HP FIRST) 43 features automatic document feeder (ADF) 28 copy module 23, ...
  • HP 8550 | Service Manual - Page 723
    ... 261 sequence of operations 258 feeding belt driver roller diagrams 31 feeding belt link...213 font support 43 foot, rubber part numbers 688 formatter, printer 304 ...FRUs ordering 41 full image function 51 full-color key 50 full-color mode selecting 50 full-color test prints 474 fuses automatic document ...
  • HP 8550 | Service Manual - Page 724
    ... G image signal 205, 210, 211 gaps printer/HCI, adjusting 159 sheet-to-sheet 149 gate... detection 311 removing parts 435 sensors 315 solenoids 316 specifications 32 troubleshooting 535 heater rings...input (HCI) 32 help, context-sensitive 49 Hewlett-Packard Distribution (HPD) ordering information 39 high...
  • HP 8550 | Service Manual - Page 725
    ...Online 40 HP Direct 44 HP Distribution ordering information 39 HP Driver Distribution Center 44 HP ... Technology (FIRST) 43 HP FIRST (Fax Information Retrieval Support Technology) 43 HP LaserJet 8550 119 HP LaserJet 8550 MFP unique parts 119 HP Technical Training 40 HPD (Hewlett-Packard Distribution)...
  • HP 8550 | Service Manual - Page 726
    ... 84, 89 resetting 90 troubleshooting 466 IMG-REG settings (color image displacement) 85, 90 inches, settings for ... inside guide plate removing 399 installing firmware image file 136 Service Support Tool...-capacity input (HCI), part numbers 657, 659, 661 non-HP, removing 457 interrupt...
  • HP 8550 | Service Manual - Page 727
    ... of operation 187 laser controller PCB 109 laser scanner motor theory of operation 187 LaserJet 8550 119 LaserJet 8550 MFP unique parts 119 last original, detecting 274 last-page detector 30 ... 99 run/check mode 94 levels, service mode screens 63 levers, part numbers 692 life span, ...
  • HP 8550 | Service Manual - Page 728
    ...option) 98 main scanning direction 222 maintenance end user 164 overdue 457 service technician 164 manuals, ordering 40 margins adjusting 85, 122 creating 51 masking, output 221 ...-1 69 BLANK 85 canceling out of 49 CCD 67 COLOR 86 control panel 94 counter mode 111 CTS-STS...
  • HP 8550 | Service Manual - Page 729
    ...-sided original 252 feeder 114 full color 50 I/O 77 ID 50 ITD cleaning ... 100 low power 235 mono-color 50 photo 109 reduced page composition 255... driver diagrams 589 driver part numbers 589 feed, troubleshooting 542 feeder 249 feeder... noise filter diagrams 583 part numbers 583 non-HP components 457 non-...
  • HP 8550 | Service Manual - Page 730
    ...-up mode 251, 256, 257 tray capacity 75 troubleshooting 462 types of 23 width-detection volume, ... 235 high-capacity input (HCI) power supply 314 troubleshooting 520, 521 overheating prevention copy module fan 234 scanner motor 192 overseas customer support 46 P page separate function 51 page tiling ...
  • HP 8550 | Service Manual - Page 731
    ... list 672 stand assembly 556, 557 unique to HP LaserJet 8550 MFP 119 parts assembling 332 disassembling 332 exchanging 41 HP Direct 44 ... replacement 163 phone number identification 44 unique to HP LaserJet 8550 MFP 119 website information 40 PASCAL menu 86, 91 passwords, erasing 57 ...
  • HP 8550 | Service Manual - Page 732
    ...570 part numbers 571 power cords part numbers 697 printer connector 26 supply connector 26 power plug 177, ... 237 overcurrent protection 235 signals 239 troubleshooting 509, 541 voltage 235 power supply ... 332 scanning lamp 194 settings 55 troubleshooting 457 powering on scanning lamp 194 sequence ...
  • HP 8550 | Service Manual - Page 733
    ... checklist 457 print engine adjustments 120 printer disassembling 332 troubleshooting 457 printer drivers handled by HP Driver Distribution Center 44 obtaining 40 request form 43 troubleshooting 457 printer formatter 304 printer power ...
  • HP 8550 | Service Manual - Page 734
    ... delivery/reversing roller 407 DIMMs 340 driver PCB, scanner motor 339 ECO-2...module) 334 motors (ADF) 387 non-HP components 457 pick-up motor ... circuit 238 jams, original 284 service mode screen 61 settings 54 ...288, 318 resolution, specifications 23 retainers, part numbers 698 retaining rolls diagrams ...
  • HP 8550 | Service Manual - Page 735
    ... diagrams 616 part numbers 617, 621, 625, 629 RGB adjustment 94 color correction, theory of 212 conversions 214 gradation... circuitry 191 driver PCB, removing 339 overheating prevention 192 removing 338 troubleshooting 525... navigating 63 run/check mode 93 service mode, navigating 63 test print mode...
  • HP 8550 | Service Manual - Page 736
    ... 471 second-side elimination 51, 121 selecting service mode screens 63 selective shift 225 ..., 640 life span 163 part numbers 641 removing 441 troubleshooting 482 separation sensor ...304 serial numbers locating 35 troubleshooting 509 series codes 70 service agreements 44 SERVICE indication 93 734 Index...
  • HP 8550 | Service Manual - Page 737
    ...96 starting 60, 61 sub-items 60 service notes HP FIRST 43 ordering 40 Service Support Tool exiting 139 ... 135 starting 136 settings backing up 62 color correction 56 common 53 copy module 54 ...pixel 207 chromatic component (Ca/Cb) 214, 215 color component 207 control card 80 control counter ...
  • HP 8550 | Service Manual - Page 738
    software matrix 43 ordering 40 support from HP FIRST 43 software counters, checking 52 software, troubleshooting 457 soiled ..., removing 422 voltage 314 solid black/solid color, troubleshooting 480 solvents 164 SPA motor ...23, 24 speed belt motor 277 color 24 full color 23 mirror mounts 192 ...
  • HP 8550 | Service Manual - Page 739
    HP FIRST (Fax Information Retrieval Support Technology) 43 HP Software Distribution Center 44 technical 42 websites 40 Support Materials Europe (SME) ordering...108 options 110 test prints 465 test strips 424 testing drums 95 keypad 94 LCD panel 94 paper feed 95 ...
  • HP 8550 | Service Manual - Page 740
    ... menu 66 versions ROM 138, 139 vertical lines, troubleshooting 483 vertical reproduction ratio 222 voltage accessory ...-width-detecting variable resistor), adjusting 157 U UCR (under color removal) processing 219 under color removal (UCR) processing 219 uneven density, troubleshooting 463, 466 uneven...
  • HP 8550 | Service Manual - Page 741
    washers important notes on 332 part numbers 709 waste toner case 69 water, cleaning with 164 wavelengths, blocks 212 weak sharpness 215 websites Service Support Tool 135 support 40 weight automatic document ...(HCI) 32 paper 29 white lines, troubleshooting causes of 470 cyan areas 466 horizontal...
  • HP 8550 | Service Manual - Page 742
    740 Index EN
  • HP 8550 | Service Manual - Page 743
    ...plastic covers Antireflecting plate (2) black screws with washers Control panel (5) M4x6 screws with washers Lamp (2) black screws with washers Scan motor driver PCB (2) M4x6 screws with washers Lamp intensity detector (1) self-tapping screw DIMM cover (2) M4x6 screws, no washers CCD cage (9)...
  • HP 8550 | Service Manual - Page 744
    Upper front cover skin (4) M4x6 screws, no washers (4) rubber covers Metal chassis plates (3) (20) brass screws, no washers: (5) on each smaller front plate Left skin (5) screws, no washers Top rear skin (3) rubber covers (5) screws, no washers (6) on back plate Metal back cover (3) screws ...
  • HP 8550 | Service Manual - Page 745
  • HP 8550 | Service Manual - Page 746
    ©Copyright 2000 Hewlett-Packard Company Manual Part Number C7834-90902 *C7834-90902* *C7834-90902* Printed on Recycled Paper C7834-90902



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HP 8550 - Color LaserJet Laser Printer Manual