HP 8550mfp Service Manual
HP 8550mfp - Color LaserJet Laser Manual
 |
View all HP 8550mfp manuals
Add to My Manuals
Save this manual to your list of manuals |
HP 8550mfp manual content summary:
- HP 8550mfp | Service Manual - Page 1
8500/8550 Printer Family Service Manual English - HP 8550mfp | Service Manual - Page 2
- HP 8550mfp | Service Manual - Page 3
HP Color LaserJet 8500/8550 Printer Family Service Manual - HP 8550mfp | Service Manual - Page 4
under copyright laws. Part number C7096-90967 First edition, April 2000 Printed in USA Warranty The information contained in this document is subject to change without notice. Hewlett-Packard makes no warranty of any kind with respect to this information. HEWLETT-PACKARD SPECIFICALLY DISCLAIMS THE - HP 8550mfp | Service Manual - Page 5
Selecting the display language 97 Installing the consumables 98 Configuring input trays 103 Verifying the printer is installed correctly 105 Verifying DIMM installation 106 Duplex registration (HP Color LaserJet 8550 107 Booklet printing 109 HP TonerGauge (HP Color LaserJet 8550 110 EN 3 - HP 8550mfp | Service Manual - Page 6
consumables 118 5 Theory of operation Chapter contents 133 Introduction 135 Color theory 138 Image formation 141 Consumable detection mechanisms 154 Electrical systems 164 Mechanical systems 169 Paper path 178 Printer timing 192 EPH controller board 199 Duplexer 199 2,000-sheet input - HP 8550mfp | Service Manual - Page 7
contents 363 Pre-troubleshooting checklist 367 Printer message troubleshooting 368 Aids to troubleshooting 415 Paper path troubleshooting 433 Image formation troubleshooting 438 Image defects troubleshooting 441 Color balance adjustment 457 Repetitive defects troubleshooting 462 Repetitive - HP 8550mfp | Service Manual - Page 8
6 Contents EN - HP 8550mfp | Service Manual - Page 9
DIMM slot configuration 106 Duplex registration 107 Removing the toner catch tray cover 116 Cleaning the toner catch tray 117 Location of consumables in printer 118 Contents of transfer kit 120 Contents of drum kit 124 Contents of fuser kit 127 Cross-section view of internal components 136 - HP 8550mfp | Service Manual - Page 10
. Figure 73. Figure 74. Waste toner level detection 155 Color toner level detection 157 Color toner lever detection 158 Density sensor 160 Transfer supply circuit 168 Laser/scanner 170 Printer motors and heaters 171 Carousel motor (M1 172 Drum motor (M2 173 Cartridge motor (M3 174 - HP 8550mfp | Service Manual - Page 11
241 Figure 94. Screws on the right lower cover 242 Figure 95. Plate, HP Color LaserJet 8550 MFP printer 243 Figure 96. Rear cover 244 Figure 97. Bottom of the control panel 246 Figure 98. Laser/scanner shield 247 Figure 99. Scanner unit 248 Figure 100. Upper airflow vent 249 Figure 101. Face - HP 8550mfp | Service Manual - Page 12
286 Figure 138. Access to main gear assembly 287 Figure 139. Developer/imaging drum bias supply, HP Color LaserJet 8550 printer 288 Figure 140. Developer/imaging drum bias supply 289 Figure 141. Post charger HV module 290 Figure 142. High-voltage power supply 291 Figure 143. Cleaning roller HV - HP 8550mfp | Service Manual - Page 13
cover 316 Figure 166. Power supply 317 Figure 167. Paper bins 318 Figure 168. Flipper assembly (1 of 3 319 Figure 169. Flipper assembly (2 of 3 319 Figure 170. Flipper assembly (3 of 3 320 Figure 171. Delivery head motor 321 Figure 172. Transport belt motor 322 Figure 173. Input paper guide - HP 8550mfp | Service Manual - Page 14
an HP Color LaserJet 8500 printer configuration page 417 Figure 213. Example of an HP Color LaserJet 8550 printer configuration page 417 Figure 214. Right upper cover detection interlock 425 Figure 215. Drum cartridge detection interlock 425 Figure 216. Black toner cartridge detection interlock - HP 8550mfp | Service Manual - Page 15
Printer covers and doors (1 of 4)-Filler panel for tray 2 (HP Color LaserJet 8550 base model only) . 519 Figure 250. Printer covers and doors (2 of 4 520 Figure 251. Printer covers and doors (3 of 4 522 Figure 252. Printer covers Figure 260. Drum/cartridge drive assembly 269. Feeder assembly 550 - HP 8550mfp | Service Manual - Page 16
Figure 283. 3,000-sheet stapler/stacker components (1 of 2) . . 570 Figure 284. 3,000-sheet stapler/stacker components (2 of 2) . . 572 14 List of Figures EN - HP 8550mfp | Service Manual - Page 17
Menu 84 Quick Copy Jobs Menu 84 Proof and Print Menu 85 Paper Handling Menu 85 Configuration Menu 88 Printing Menu 89 I/O Menu 91 I/O Menu 91 Resets Menu 92 Color Adjust Menu 92 Service Mode Menu 93 Replacement frequencies for printer consumables . . 119 Subtractive color absorption 138 - HP 8550mfp | Service Manual - Page 18
components parts (6 of 6 539 Drum/cartridge drive assembly parts 540 Delivery drive assembly parts 541 Tray 3 assembly parts 542 Tray 2 assembly 543 Paper pick-up assembly parts 547 Registration frame assembly parts 548 Registration roller assembly parts 549 Feeder assembly parts 550 - HP 8550mfp | Service Manual - Page 19
91. Table 92. Delivery assembly parts 553 Delivery cover assembly parts 554 Transfer belt assembly parts 555 Fuser assembly parts 558 PCA assembly parts 559 2,000-sheet input unit cover and door parts 561 2,000-sheet input unit internal component parts . . . . 563 Multi-bin mailbox component - HP 8550mfp | Service Manual - Page 20
18 List of Tables EN - HP 8550mfp | Service Manual - Page 21
1 Product information Chapter contents Introduction 21 Printer features 22 Specifications 24 Electrical specifications 24 Operating environment specifications 24 Acoustic emission specifications 25 Printer dimensions 25 Consumable storage specifications 26 Site requirements 27 General - HP 8550mfp | Service Manual - Page 22
statement (Japan)-8500 models 54 VCCI statement (Japan)-8550 models 54 EMI statement (Korea)-8500 models 54 EMI statement (Korea)-8550 models 54 Laser safety statement 55 Laser statement for Finland 56 Product information sheet 57 Toner safety 57 Material Safety Data Sheet (MSDS 57 Ozone - HP 8550mfp | Service Manual - Page 23
HP Color LaserJet 8550 DN printer HP Color LaserJet 8550 GN printer HP Color LaserJet 8550 MFP-print engine only Service topics for the HP Color LaserJet 8550 MFP printer's copy module, automatic document feeder, and 1,000-sheet input paper deck are not included in this manual. See the HP Color - HP 8550mfp | Service Manual - Page 24
X Copy module X External (EIO- compatible) printer X X hard disk DRAM DIMMs (synchronous) X X X X X X X X Duplexer2 X X X X HP JetDirect EIO card X X Accessories 500-sheet input tray X 1,000-sheet paper deck (input) X Automatic document feeder X Multi - HP 8550mfp | Service Manual - Page 25
17 inch size Heavy paper Transparencies Fonts Printer personality support User interface and EIO 12 ppm b/w; 3 ppm color 3.2 ppm b/w; 2.2 ppm color 2.6 ppm b/w; 2.0 ppm color TrueType™ rasterizer in both HP PCL and Adobe PostScript® 45 scalable HP typefaces 136 scalable Adobe PostScript - HP 8550mfp | Service Manual - Page 26
2 W 6.0 A at 220 V Operating environment specifications Table 4. Operating environment specifications Item Operating Storage Temperature Recommended Allowed 20 to 26 the HP Color LaserJet 8550 MFP printer service manual for dimensions that include copy module, automatic document feeder, and - HP 8550mfp | Service Manual - Page 27
Acoustic emission specifications Table 5. Acoustic emissions Category Operation position (per ISO Standby: 6.3 B (A) 8550 LpA 57 dB(A) LpA 52 dB(A) LpA 54 dB(A) LpA 47 dB(A) 7.0 B (A) 6.4 B (A) Printer dimensions Table 6. Printer dimensions Category Printer Printer with stand Height 750 - HP 8550mfp | Service Manual - Page 28
of consumables is greatly affected by their storage environment. Use the following table to determine the shelf life of stored consumables. For consumable replacement specifications, see page 119. Table 7. Consumable storage specifications Temperature Normal (maximum of 2.5 years) 0 to 35° C (32 to - HP 8550mfp | Service Manual - Page 29
at the factory. In particular, be sure to adhere to the environmental specifications listed in this chapter. The following are recommendations for locating and placing the printer: Install in a well-ventilated, dust-free area. Install on a hard, level surface. Install where the temperature and - HP 8550mfp | Service Manual - Page 30
Note Space requirements See the HP Color LaserJet 8550 MFP printer service manual for space requirements for the copy module, automatic document feeder, and 1,000-sheet input paper deck. 290 mm 11 in 1404 mm 55 in 1 460 mm 18 in 363 mm 14 in 1085 mm 43 - HP 8550mfp | Service Manual - Page 31
problems, and problems requiring service. This service might not be covered by the HP warranty or service agreements. Before purchasing media or specialized forms, test a small quantity in the printer. Make sure your media supplier obtains and understands the media specifications in the HP LaserJet - HP 8550mfp | Service Manual - Page 32
Leave media in the wrapper until you are ready to use it. Rewrap partially used packages of media before storing. Stack cartons upright and . When storing printed documents: Do not store printed documents in vinyl folders. Do not expose printed documents to petroleum-based solvents - HP 8550mfp | Service Manual - Page 33
, use HP LaserJet paper or conventional white copier paper. The media should be of good quality and free of cuts, nicks, tears, spots, loose particles, dust, wrinkles, voids, perforations, and curled or bent edges. For a complete list of media specifications, see the HP LaserJet Printer Family - HP 8550mfp | Service Manual - Page 34
g/m2) bond Limit to media-fill mark on the media width guides. 2,000 sheets of 20 lb (75 g/m2) bond Limit to media-fill mark on the media width guides. 2,000-sheet input tray *A3 full-bleed is not supported by any of the HP CLJ 8500 or 8550 models. 32 Chapter 1 - Product information EN - HP 8550mfp | Service Manual - Page 35
type Media size Media weight Maximum capacity Mailboxes Paper Plain Preprinted Letterhead Prepunched Bond Recycled Color 11 by 17 in A3* A4 JIS B4 Legal Letter 16 to 28 lb bond envelopes *A3 full-bleed is not supported by any of the HP CLJ 8500 or 8550 models. EN Media requirements 33 - HP 8550mfp | Service Manual - Page 36
(this is the maximum area that can be addressed by the laser beam). Recommended print area-the maximum area in which image signals can area in which print quality can be assured, including manual feed. Table 10. Printable area specification Media type Non-masked print area Cut sheet - HP 8550mfp | Service Manual - Page 37
bin for all HP Color LaserJet 8550 printer models. The printer's internal color settings are optimized for the best color quality if Transparency is selected as the media type in the printer driver. Using other media type settings will result in less accurate colors. The printer only supports - HP 8550mfp | Service Manual - Page 38
Glossy media If you want the effect of glossy media, use only HP LaserJet soft gloss media in this printer. HP soft gloss is the only glossy media supported by the printer. For ordering information, see page 513. Heavy paper stock Heavy paper stock is any paper from 28 lb to 58 lb (105 to 216 g/m2). - HP 8550mfp | Service Manual - Page 39
a photocopier or laser printer (even if there is no printing on the page) unless you use the "manual print second side" printers any glossy media other than HP soft gloss media media with texture or finish different from one side to the other creased or folded media (except for supported - HP 8550mfp | Service Manual - Page 40
and serial number, find the label located on the rear of the printer, similar to the one shown in figure 2 (the example shown is from an HP Color LaserJet 8500 printer). (serial #) Figure 2. (model #) Example of printer model number and serial number label (110 V and 220 V) 38 Chapter 1 - Product - HP 8550mfp | Service Manual - Page 41
for the HP Color LaserJet 8500 printer appear below; available configurations for the HP Color LaserJet 8550 printer are shown on the following page. The HP Color LaserJet 8500 printer is available in the following configurations: HP Color LaserJet 8500 The HP Color LaserJet 8500 comes - HP 8550mfp | Service Manual - Page 42
processor. HP Color LaserJet 8550 MFP The HP Color LaserJet 8550MFP comes standard with a 100-sheet tray 1, a 500-sheet tray 2, a 500-sheet tray 3, a duplexer, 64 MB RAM, an HP JetDirect print server (10/100 Base-TX), an internal hard disk, a printer/copy module stand, and a copy module. 40 - HP 8550mfp | Service Manual - Page 43
is immobilized in HP Color LaserJet 8550 MFP printers. Use the power button at the top, right of the copy module after plugging the printer power cable into the right side of the copy module. See the HP Color LaserJet 8550 MFP printer user guide for more information. EN Printer Information 41 - HP 8550mfp | Service Manual - Page 44
3 1 4 2 5 Figure 4. Rear view 1 Air filter door 2 Formatter tray 3 Left upper cover 4 Left lower cover 5 Power connector 42 Chapter 1 - Product information EN - HP 8550mfp | Service Manual - Page 45
Printer hard disk location (factory-installed on HP Color LaserJet 8500 N, 8500 DN, 8550 N, 8550 DN, 8550 GN, and 8550 MFP models) 4 EIO slot 2 (shown with HP the formatter board. However, the printer does not support two hard disks; the printer can support one hard disk at a time-either internal or external - HP 8550mfp | Service Manual - Page 46
1 Multi-bin mailbox 2 Multi-bin mailbox status light 3 Duplexer (internal) 4 Tray 2 5 2,000-sheet input tray (tray 4) (only available on 8500 DN, 8550 DN, and 8550 GN models) 6 Tray 4 status light 7 Media transfer door (attached to tray 4) 8 3,000-sheet stapler/stacker or 3,000-sheet stacker (only - HP 8550mfp | Service Manual - Page 47
a page needs to be removed from the multi-bin mailbox, even if the page is not jammed. The accessory is not correctly attached to the printer. The accessory has a media jam or a staple jam, or one or more bins are full. The accessory is not correctly attached to the - HP 8550mfp | Service Manual - Page 48
Class B digital device, pursuant to Part 15 of the U.S. Federal Communications Commission uses, and can radiate radio frequency energy, and if not installed and used in accordance with the instructions printer not expressly approved by HP could void the user's authority to operate this equipment. Use - HP 8550mfp | Service Manual - Page 49
Name: Model Number: Product Options: HP Color LaserJet 8500, 8500 N, 8500 DN C3983A, C3984A, C3985A ALL conforms to the following Product Specifications: Safety: IEC 950:1991+A1+A2+A3+A4 / EN 60950:1992+A1+A2+A3+A4 IEC 825-1:1993 / EN 60825-1:1994 Class 1 (Laser/LED) EMC: CISPR 22:1993+A1 - HP 8550mfp | Service Manual - Page 50
Options: HP Color LaserJet 8550, 8550 N, 8550 DN, 8550 GN, 8550 MFP C7096A, C7097A, C7098A, C7099A, C7835A, C7836A ALL conforms to the following Product Specifications: Safety: IEC 950:1991+A1+A2+A3+A4 / EN 60950:1992+A1+A2+A3+A4+A11 IEC 825-1:1993 / EN 60825-1:1994+A11 Class 1 (Laser/LED - HP 8550mfp | Service Manual - Page 51
Guide 22 and EN 45014 Manufacturer's Name: Manufacturer's Address: Hewlett-Packard Company Montemorelos 299 Guadalajara Jalisco, 45060 México declares, that the product Product Name: Model Number: Product Options: Duplexer C4782A N/A conforms to the following Product Specifications Part Service - HP 8550mfp | Service Manual - Page 52
Guide 22 Specifications: Safety: IEC 950:1991+A1+A2+A3+A4 / EN 60950:1992+A1+A2+A3+A4 IEC 825-1:1993 / EN 60825-1:1994 Class 1 (Laser Signal Lines 1.0 kV Power Lines FCC Title 47 CFR, Part 15 Class B2/ICES-003, Issue 2/VCCI-21 AS Local Hewlett-Packard Sales and Service Office or Hewlett-Packard - HP 8550mfp | Service Manual - Page 53
/IEC Guide 22 -0.5 kV Signal Lines 1.0 kV Power Lines FCC Title 47 CFR, Part 15 Class B2 / ICES-003, Issue 2/VCCI-B1 AS / NZS 825-1:1993 / EN 60825-1:1994 Class 1 (Laser/LED) Telecom N/A Additional Information: The product A Local Hewlett-Packard Sales and Service Office or Hewlett-Packard GmbH, - HP 8550mfp | Service Manual - Page 54
ISO/IEC Guide 22 and -0.5 kV Signal Lines 1.0 kV Power Lines FCC Title 47 CFR, Part 15 Class B2 / ICES-003, Issue 2/VCCI-B1 AS / 825-1:1993 / EN 60825-1:1994 Class 1 (Laser/LED) UL1950, Third Edition Additional Information: A Local Hewlett-Packard Sales and Service Office or Hewlett-Packard GmbH, - HP 8550mfp | Service Manual - Page 55
Guide Signal Lines 1.0 kV Power Lines FCC Title 47 CFR, Part 15 Class B2 / ICES-003, Issue 2/VCCI-B1 / EN 60825-1:1994 Class 1 (Laser/LED) UL1950, Third Edition Additional HP Color LaserJet 8550 MFP printer Service Manual for Declarations of Conformity for the copy module, automatic document feeder - HP 8550mfp | Service Manual - Page 56
VCCI statement (Japan)-8500 models VCCI statement (Japan)-8550 models EMI statement (Korea)-8500 models EMI statement (Korea)-8550 models 54 Chapter 1 - Product information EN - HP 8550mfp | Service Manual - Page 57
Department of Health and Human Services (DHHS) Radiation Performance Standard according to the Radiation Control for Health and Safety Act of 1968. Because radiation emitted inside this printer is completely confined within protective housings and external covers, the laser beam cannot escape during - HP 8550mfp | Service Manual - Page 58
statement for Finland Luokan 1 laserlaite Klass 1 Laser Apparat HP LaserJet 8500, 8500 N, 8500 DN laserkirjoitin on käyttäjän kannalta turvallinen luokan 1 laserlaite. Normaalissa käytössä kirjoittimen suojakotelointi estää lasersäteen pääsyn laitteen ulkopuolelle. Laitteen turvallisuusluokka on - HP 8550mfp | Service Manual - Page 59
to melt and permanently fuse into clothing. Material Safety Data Sheet (MSDS) The Toner Cartridge/Drum MSDS can be viewed on the World Wide Web at the following URL: http://www.hp.com Click "Search" and enter "MSDS" where appropriate. International customers should see page 66 for appropriate phone - HP 8550mfp | Service Manual - Page 60
emission The corona assemblies found in laser printers and photocopiers generate ozone gas (O3) as a by-product of the electrophotographic process. Ozone is generated only while the printer is printing (while the coronas are energized). This HP LaserJet printer contains an charcoal filter to protect - HP 8550mfp | Service Manual - Page 61
Technical assistance 64 List Server 64 HP ASAP 64 Dealer Response Line 65 HP Software Distribution Center 66 HP Direct 66 Parts identification 66 Customer Information Centers 66 HP Customer Care Centers 67 Warranty 69 Installation 69 Toner cartridge information 69 EN Chapter contents - HP 8550mfp | Service Manual - Page 62
60 Chapter 2 - Service approach EN - HP 8550mfp | Service Manual - Page 63
the location of the problem. Usually, simply sending a print job to the printer from a computer is sufficient to determine whether or not the print engine is involved. If it is not, see the service manual specific to the HP Color LaserJet 8550 MFP printer. Once a faulty part is located, repair is - HP 8550mfp | Service Manual - Page 64
Care Online http://www.hp.com/go/support Software drivers, support documentation, and answers to frequently asked questions HP Technical Training (North America) Classes and schedules http://www.hp.com/go/resellertraining Parts Parts information http://outfield.external.hp.com/spi/welcom.htm - HP 8550mfp | Service Manual - Page 65
field-replaceable units This printer is designed to be repaired by replacing field-replaceable units. Part numbers are located in chapter 8 of this manual and can be ordered from SMO or SME (see page 62). Parts exchange program HP offers remanufactured assemblies for some selected parts. These are - HP 8550mfp | Service Manual - Page 66
or fax card. Service-related information includes: service notes (HP Authorized Dealers) Product Data Sheets Material Safety Data Sheets (MSDSs) typeface and accessory information printer support software information toner information driver request form and Software Matrix 64 Chapter - HP 8550mfp | Service Manual - Page 67
countries listed above, call (31) 20-681-8192. Dealer Response Line For further technical assistance on pre/post-sales and service support, HP dealer service-authorized personnel can contact the Dealer Response Line: (1) (800) 544-9976, U.S. only (1) (800) 363-6584, Canada EN Technical assistance - HP 8550mfp | Service Manual - Page 68
Software Distribution Center For printer drivers and application note orders: (1) (805) 257-5565 HP Direct For supplies and accessories orders: (1) (800) 538-8787, U.S. only Customer Support Sales Center For existing hardware and software service agreements: (1) (800) 386-1115, U.S. only For price - HP 8550mfp | Service Manual - Page 69
your dealer. Each time you call the HP Customer Care Centers, you will be asked to provide the printer serial number and the original date of 8:30 am until 6:00 pm central European time. Multilingual customer support representatives are available to answer questions. Canadian Customer Care Center ( - HP 8550mfp | Service Manual - Page 70
, Monday through Friday Vietnam +84 (0) 8 823 4530 8:00 am to 5:00 pm, Monday through Friday, and 8:00 am to noon pm on Saturday 68 Chapter 2 - Service approach EN - HP 8550mfp | Service Manual - Page 71
specific legal rights. There might also be other rights that vary from area to area. Refer to the user's guide for further warranty information. Installation Installation by service personnel is included with the HP Color LaserJet 8500 DN printer and is required with the HP Color LaserJet 8550 MFP - HP 8550mfp | Service Manual - Page 72
Recycling toner cartridges To reduce waste, HP offers a recycling program for used toner cartridges. Cartridge components that do not wear out are recycled. Plastics and other materials are recycled. HP pays the shipping costs from the user to the recycling facility. 70 Chapter 2 - Service approach - HP 8550mfp | Service Manual - Page 73
Quick Copy Jobs Menu (HP Color LaserJet 8550) . . . 84 Private/Stored Jobs Menu (HP Color LaserJet 8550) . 85 Paper Handling Menu 85 Configuration Menu 88 Printing Menu 89 Duplex Registration Menu (HP Color LaserJet 8550) . 91 I/O Menu 91 Resets Menu 92 Color Adjust Menu 92 Service Mode Menu - HP 8550mfp | Service Manual - Page 74
type and size 104 Verifying the printer is installed correctly 105 Configuration page 105 EIO page 105 Verifying DIMM installation 106 Duplex registration (HP Color LaserJet 8550 107 Booklet printing 109 HP TonerGauge (HP Color LaserJet 8550 110 Resetting the HP TonerGauge 110 72 Chapter - HP 8550mfp | Service Manual - Page 75
One software CD-ROM and one documentation CD-ROM 4 Manuals: getting started guide and quick reference guide 5 Imaging drum 6 Printer control panel overlay (if applicable) 7 Media size labels 8 Left (face-up) output bin 9 An HP Color LaserJet 8500 (shown above), 8500 N, 8500 DN, 8550, 8550 N, 8550 DN - HP 8550mfp | Service Manual - Page 76
installed Verify that the cables are connected to the printer correctly. Printer with stand Figure 8. Power cord connection WARNING! An unstable printer can tip over and cause injury; verify that the printer is secured properly and the printer wheels are locked. o The power cord plugs into the - HP 8550mfp | Service Manual - Page 77
shorter of the two cables from the power pack plugs into the connector on the back left corner of the printer. o The longer of the two cables from the power pack plugs into the connector on the back left corner of the 2,000-sheet input unit. o - HP 8550mfp | Service Manual - Page 78
connection at a time-RJ-45 or BNC. l HP JetDirect 10/100TX print server supports RJ-45 (unshielded twisted pair) cables for 10Base-T or 100Base-TX networks. B A C Figure 10. Network connections The locations of ports on the HP JetDirect internal printer server are: A RJ-45 port (this is the - HP 8550mfp | Service Manual - Page 79
be connected to a LocalTalk network in addition to an Ethernet or 10Base2 network. If you use only the LocalTalk port, EIO 1 INITIALIZING appears every time you turn the printer on if you have an HP JetDirect internal print server installed in EIO port 1. The message should not interfere with normal - HP 8550mfp | Service Manual - Page 80
cable Figure 11. Parallel cable connection o To print through the parallel port, the printer requires a 25-pin male/micro 36-pin male ("C-size") parallel cable that is IEEE-1284 compliant. The cable is included with the base model of this printer only. It must be purchased separately for other - HP 8550mfp | Service Manual - Page 81
control panel overlay with the one included for your language, if applicable. Then configure the printer control panel to show printer messages in your language (see page 97). Figure 12. Changing the printer control panel overlay 1 Insert a thin, rigid object under the two edges of the overlay on - HP 8550mfp | Service Manual - Page 82
menus. LCD display Presents data about the printer (such as printer status, required actions, or data and print errors) in one or two lines of characters. - Value + Steps through the value choices for a particular menu item using - or +. This key permits both forward and backward movement through - HP 8550mfp | Service Manual - Page 83
through the items in a particular menu. This key permits both forward and backward movement through the available items. Use the right side of the key to activate online help in all HP Color LaserJet 8550 printer models. Ready Indicator (green) l On-The printer is online and able to accept and - HP 8550mfp | Service Manual - Page 84
is online. In a menu mode, if no keys are pressed for approximately 30 seconds, the system automatically returns to the top level and displays one of the following: l READY if the printer was online l OFFLINE if the printer was offline l an existing error or service message Making selections in the - HP 8550mfp | Service Manual - Page 85
soft fonts. Shows installed PostScript fonts. Prints a demonstration page for sales purposes. Appears only if the printer has a hard disk installed. Appears only if an EIO device is installed that supports EIO page printing. Used for testing printer operation. Shows printer events. EN Menu maps 83 - HP 8550mfp | Service Manual - Page 86
. - Or Press CANCEL JOB or set the number of copies to zero to delete the remaining copies. Quick Copy Jobs Menu (HP Color LaserJet 8550) This menu appears only if the printer has a hard disk installed. Table 17. Quick Copy Jobs Menu Item - HP 8550mfp | Service Manual - Page 87
Private/Stored Jobs Menu (HP Color LaserJet 8550) This menu appears only if the printer has a hard disk installed. Table SELECTED PRINTED SELECTED PRINTED Description/action = Number of copies To cancel private and stored jobs: 1 Press ITEM to display the job name and job owner - HP 8550mfp | Service Manual - Page 88
Appears only if TRAY 1 MODE=CASSETTE. PLAIN* PREPRINTD (plain and preprinted are combined to one menu item on the 8550) LTRHEAD TRNSPRNCY (trays 2 and 3 only) PREPUNCHED BOND RECYCLED COLOR GLOSSY 28# TYPE 1 28# TYPE 2 The TRAY 4 TYPE= option appears only if the 2,000-sheet input unit is properly - HP 8550mfp | Service Manual - Page 89
displays TRAY LOAD . After a delay the printer automatically prints on the default media. The delay time can be changed through HP JetAdmin software. * Default setting. If OFF is selected, the printer displays TRAY LOAD until it detects the requested media - HP 8550mfp | Service Manual - Page 90
WARNINGS= ON* JOB TONER LOW= CONTINUE* STOP NEW TONER CARTRIDGE= (8550 only) QUICK COPY JOBS = (8550 only) PRINT PS ERRORS= NO YES 0 to 50 OFF* ON INITIALIZE DISK None * Default setting. Description/action Sets the length of time after use before the printer switches to powersave mode - HP 8550mfp | Service Manual - Page 91
copies is not defined by the print job. PAPER= LETTER* LEGAL A4 EXEC A5 11X17 A3 JIS B4 JIS B5 JPOSTD Sets the default media size. The default media size is used for jobs that do not include media size commands, or when the requested media size is not installed in the printer - HP 8550mfp | Service Manual - Page 92
that do not include symbol-set selection commands. DARK emulates the heavier Courier font of the HP LaserJet III printer. REGULAR is the lighter and more accurate Courier font used since the HP LaserJet 4 printer and in books and magazines. Allows the user to change the printable area of A4-sized - HP 8550mfp | Service Manual - Page 93
markers. PARALLEL ADV FUNCTIONS= ON* OFF 1Default setting for HP Color LaserJet 8550. 2Default setting for HP Color LaserJet 8500. Forces parallel port to compatibility mode, which can be more reliable in some cases, but will not allow the printer status to be sent to the host computer. EN - HP 8550mfp | Service Manual - Page 94
Menu values do not change. Resets I/O to known state. Used to clear I/O problems. Used to indicate that a new transfer kit has been installed. Used to indicate that a new fuser kit has been installed. Color Adjust Menu Table 25. Color Adjust Menu Item Value PRINT TEST PAGE None BLACK SMOOTH - HP 8550mfp | Service Manual - Page 95
is implemented within formatter diagnostics to record errors for review. • Because many of the formatter diagnostic tests are destructive memory tests, a special key sequence is used to enter the mode. A message warns service personnel that the printer is about to perform destructive memory tests - HP 8550mfp | Service Manual - Page 96
Service Mode Menu (continued) Service Mode Menu Item NVRAM SETTING (continued) DUPLEX COUNT TRANSFER LIFE LEFT Value FUSER engine used to align the various color planes. The values are listed on a sticker inside the front of the printer (to the left of the printer control - HP 8550mfp | Service Manual - Page 97
. YES* NO Installed DIMMs are tested to verify that they are supported by the formatter board and functioning properly. YES* NO This test verifies the read and write integrity of the formatter IDE ASIC. YES* NO Used to verify the integrity of the printer hard disk and the interface between the - HP 8550mfp | Service Manual - Page 98
Table 26. Service Mode Menu (continued) Service Mode Menu Item REPETITIONS TRAY 1= TRAY 2= TRAY 3= OUTPUT = DEVELOPER MOTOR REPETITIONS EXECUTE TEST DRUM MOTOR REPETITIONS EXECUTE TEST SENSOR MONITOR EXECUTE TEST Value Description/action 1* . . . 10 ON* OFF ON* OFF ON* OFF TOP OUTPUT - HP 8550mfp | Service Manual - Page 99
keys are ignored. If you press GO without selecting a language, the printer printer in the configure language mode. 4 Press GO. 5 Turn the printer off and back on. See the HP Color LaserJet 8550 MFP printer Service Manual for information about how to change the display language on the copy module - HP 8550mfp | Service Manual - Page 100
Installing the consumables When installing a new printer, install the consumables in the printer in this order: 1 Imaging drum 2 Black toner cartridge 3 Color toner cartridges 1 2 3 Figure 14. Consumables installation 98 Chapter 3 - Operational overview EN - HP 8550mfp | Service Manual - Page 101
to the right (C). CAUTION There is a cover protecting the drum cylinder. Do not remove this cover or the drum might be damaged; it will come off during the next step. 2 Push the drum into the printer. The protective cover slides off as the drum enters the printer. 3 Swing the lower (green) lever - HP 8550mfp | Service Manual - Page 102
at the top of the slot in the printer and slide the cartridge into the printer. 3 Place one hand on the cartridge and 3 use the other hand to pull the orange ring and remove the seal. Discard the seal. Note If toner gets on fabric, wipe the toner off with a dry cloth and then wash the - HP 8550mfp | Service Manual - Page 103
color toner cartridges 1 With the printer on, press the blue button beneath the carousel door to turn the carousel to a toner cartridge imaging drum is installed completely 3 l the black toner cartridge is installed completely l the orange seal is removed from the black toner cartridge l - HP 8550mfp | Service Manual - Page 104
at the top of the slot. Slide the cartridge into the printer. Note If the cartridge does not slide completely into the printer, make sure that the color of toner in the cartridge matches the colored sticker on the slot. 5 5 Place one hand on the cartridge and use the other hand to pull the orange - HP 8550mfp | Service Manual - Page 105
When input trays are configured correctly, the printer automatically uses the correct input tray based on media is a different size than the media specified in the printer driver, then the printer does not feed the media (to prevent toner residue on subsequent pages). In CASSETTE mode, tray 1 - HP 8550mfp | Service Manual - Page 106
, labels, and transparencies). These adjustments give the highest quality output, saving time and resources. If the media type is not set correctly, then the printer might not print on the correct media or at the correct speed for the media type, which can result in poor print quality or excessively - HP 8550mfp | Service Manual - Page 107
control panel display. 2 Press ITEM until PRINT CONFIG PAGE appears on the display. 3 Press SELECT to print the configuration page. EIO page Use the printer control panel to print an EIO page to verify network configuration. To print an EIO page 1 Press MENU until INFORMATION MENU appears on the - HP 8550mfp | Service Manual - Page 108
models l 32-MB DIMMs in the DN model The HP Color LaserJet 8550 printer comes with the following amounts of memory installed in slots MFP models (2 x 32 = 64) l 64-MB DIMMs in the GN model (2 x 64 = 128) In all printer models, slots 3 through 8 are available for additional DIMMs. The printer supports - HP 8550mfp | Service Manual - Page 109
printer use -VALUE+ to enter the number you selected from the test page in step 4. 7 Press SELECT to store the value. An asterisk in the lower right corner of the display indicates the currently stored value. 8 Repeat steps 6 and 7 for the y axis. EN Duplex registration (HP Color LaserJet 8550 - HP 8550mfp | Service Manual - Page 110
Note 9 Press ITEM to scroll up through the duplex registration menu until PRINT TEST PAGE appears for the tray you want. 10 Press SELECT to print the page. 11 Repeat step 4 to verify that the lines on the front and back of the page are now properly aligned. If the lines on the front and back do not - HP 8550mfp | Service Manual - Page 111
is available on all HP Color LaserJet 8550 printer models and on HP Color LaserJet 8500 models with the PCL upgrade. Booklet printing allows the pages of a print job to be arranged so that the document can be folded and stapled or bound into a book. Booklet printing is supported in PostScript and - HP 8550mfp | Service Manual - Page 112
feature is not enabled on HP Color LaserJet 8550 MFP printers. The HP TonerGauge feature allows the user to estimate how much toner is left in the cartridges. The HP TonerGauge indicator appears on the configuration page, on the status tab of the driver, and in HP Web JetAdmin (for the network - HP 8550mfp | Service Manual - Page 113
maintenance Chapter contents Cleaning procedures 113 Cleaning the post charger 113 Cleaning the density sensor 114 Cleaning the transfer charger 115 Cleaning the toner catch tray 116 Printer consumables 118 Replacement frequencies 119 Replacing consumables 120 EN Chapter contents 111 - HP 8550mfp | Service Manual - Page 114
112 Chapter 4 - Printer maintenance EN - HP 8550mfp | Service Manual - Page 115
light streaks in halftone areas. To clean the post charger 1 Open the right upper door. 2 Locate the post charger unit cleaner next to the transfer drum handle. 3 Slide the post charger unit cleaner across the bar several times. 4 Push the cleaner back into place. 5 Close the right upper door. EN - HP 8550mfp | Service Manual - Page 116
sensor after replacing the imaging drum and when printed colors are inaccurate. To clean the density sensor and erase lamp 1 Open the right upper door. 2 On the inside of the door, locate the density sensor and the density sensor brush. Use the brush to brush off toner particles from the density - HP 8550mfp | Service Manual - Page 117
Cleaning the transfer charger Clean the transfer charger when irregular wavy patterns appear in solid backgrounds. To clean the transfer charger 1 Open the front door. 2 Find the knob below the transfer charger. 3 Pull the knob out and push it back in. 4 Close the front door. EN Cleaning - HP 8550mfp | Service Manual - Page 118
Cleaning the toner catch tray The toner catch tray will not normally have much toner in it. Clean the toner catch tray before moving the printer to another location or when performing routine maintenance at the customer site. 1 Open the front door. 2 Remove the toner catch tray cover by releasing - HP 8550mfp | Service Manual - Page 119
there is a small amount of toner in the tray. WARNING! Do not use a regular vacuum to clean up toner. The toner can penetrate the vacuum bag, and toner might be harmful if inhaled. Figure 18. Cleaning the toner catch tray 5 Reinstall the toner catch tray and cover, and close the front door. EN - HP 8550mfp | Service Manual - Page 120
of consumables in printer 1 Color toner cartridges 2 Black toner cartridge 3 Imaging drum 4 Cleaning roller 5 Transfer belt 6 Transfer drum 7 Air filters 8 Transfer charger 9 Pick-up/feed rollers 10 Charcoal filter 11 Fuser HP encourages responsible disposal of HP printer consumables through its - HP 8550mfp | Service Manual - Page 121
Consumable Printer message Page count Approximate time period1 Black toner cartridge Color toner cartridges Cyan Magenta Yellow TONER LOW REPLACE BLACK TONER LOW REPLACE [color] 17,000 pages2 8,500 pages2 2.5 months 1.1 to 1.6 months Drum kit Imaging drum Air filters (2) Hand wipe DRUM LIFE - HP 8550mfp | Service Manual - Page 122
black and color toner cartridges, see page 100 and page 101. Transfer kit Replace the parts in the transfer kit when the printer control panel displays: TRANSFER KIT LOW / REPLACE KIT TRANSFER KIT OUT / REPLACE KIT 1 2 3 5 4 6 Figure 20. Contents of transfer kit 1 Transfer drum 2 Transfer belt - HP 8550mfp | Service Manual - Page 123
kit 1 Open the front door of the printer. 2 Push the white button on the lower (green) lever and swing the lever to the right. 3 Open the upper door on the right side of the printer, and remove the 4 transfer drum and left end to avoid print quality problems. 5 While holding the new roller by - HP 8550mfp | Service Manual - Page 124
inside the printer. Place the gear side in the notch first to mesh the gear teeth. 10 Rotate the belt down into place. Note Damage to the drum can cause print 11 quality problems. Hold the drum only by the handles. 11 Remove the protective sheet covering the new transfer drum by pulling - HP 8550mfp | Service Manual - Page 125
on the printer control panel display. b. Press ITEM until RESET TRANSFER LIFE COUNT appears. c. Press SELECT to reset the transfer drum life count. d. Press GO to bring the printer online. 22 Place the used parts in the packaging from the new ones. See the included recycling guide for recycling - HP 8550mfp | Service Manual - Page 126
the parts in the imaging drum kit when the printer control panel displays any of the following messages: DRUM LIFE LOW / REPLACE DRUM KIT DRUM LIFE OUT / REPLACE DRUM KIT DRUM ERROR / REPLACE DRUM KIT 3 1 2 Figure 21. Contents of drum kit 1 Two air filters 2 Hand wipe 3 Imaging drum cartridge - HP 8550mfp | Service Manual - Page 127
to order a replacement imaging drum kit before "drum life out." The user can continue to operate the HP Color LaserJet 8500/8550 printer until "drum life out" occurs, at which point the printer will not operate. The user should be advised that: Drum life specification assumes two-page jobs, one - HP 8550mfp | Service Manual - Page 128
blue handle on the top of the drum and remove the imaging drum. CAUTION A gray cover protects the new imaging drum. Do not remove this cover; it will come off during the next step. 4 4 Line up the guides and push firmly to slide the new drum into the printer. The cover will slide off as the - HP 8550mfp | Service Manual - Page 129
filter door. If the filter door does not close, make sure the filters 9 are in place. Use the hand wipe to remove toner from your hands. 12 Place the used parts in the packaging from the new ones. See the included recycling guide for recycling information. 10 12 EN Printer consumables 127 - HP 8550mfp | Service Manual - Page 130
Fuser kit Replace the parts in the fuser kit when the printer control panel displays: FUSER LIFE LOW / REPLACE KIT FUSER LIFE OUT / REPLACE KIT 1 2 3 Figure 22. Note Contents of fuser kit 1 Fuser 2 Hand wipe 3 Six paper rollers The paper rollers are all the same; any of the rollers can be used in - HP 8550mfp | Service Manual - Page 131
side of the duplexer and pull the 5 duplexer out of the printer. 4 To unlock the fuser, rotate the blue levers down. 5 On the right side of the fuser, lift the large green lever to release the fuser springs. 6 On the left side of the fuser, rotate 6 the blue gear down two or three times to - HP 8550mfp | Service Manual - Page 132
tabs on both ends, and then pull the fuser out. 8 Use the blue tabs on the new fuser to slide it into the printer along the guides. On the left side of the fuser, rotate the blue gear up two or three times until the fuser drops into place. 8 CAUTION Use only the blue tabs to push the - HP 8550mfp | Service Manual - Page 133
the other three rollers. 5 Replace trays 3 and 2. Note Trays 2 and 3 are not interchangeable. 6 If an optional 2,000-sheet input unit is not attached to the printer, proceed to step 9. If a 2,000-sheet input unit is attached, open the vertical transfer door on the right side of the - HP 8550mfp | Service Manual - Page 134
control panel display. b. Press ITEM until RESET FUSER LIFE COUNT appears. c. Press SELECT to reset the fuser life count. d. Press GO to bring the printer online. 12 Place the used parts in the packaging from the new ones. See the included recycling guide for recycling information 132 Chapter - HP 8550mfp | Service Manual - Page 135
block 153 Consumable detection mechanisms 154 Drum kit life detection 154 Transfer kit life detection 156 Color toner lever detection 158 Black toner level detection and cartridge detection . . 159 Environment change control 159 Color calibration density sensor 160 Transfer belt control - HP 8550mfp | Service Manual - Page 136
distribution 164 Fuser control 166 High-voltage power supply circuit 167 Mechanical systems 169 Laser/scanner 169 Motors and heaters 171 Paper path 178 Pick-up/feed 179 Sensors, switches, clutches, and solenoids 184 Fusing and delivery unit 190 Media jam detection 192 Printer timing 192 - HP 8550mfp | Service Manual - Page 137
the theory of operation and the functional overview for the printer. It provides the service representative with an understanding of the printing process required to service the printer. This chapter discusses the following: Color theory Image formation Paper path Mechanical drive system - HP 8550mfp | Service Manual - Page 138
Figure 23 shows a cross-sectional view of the internal components of the printer. 1 2 34 5 30 29 28 27 26 25 24 23 6 7 8 9 10 11 12 13 14 Figure 23. 22 21 20 19 18 17 16 15 Cross-section view of internal components 136 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 139
toner cartridge 17 Registration roller 2 Imaging drum 18 Transfer charger 3 Charging roller 19 Upper fusing roller 4 Imaging drum cartridge 20 Lower fusing roller 5 Laser/scanner (face-up) output bin 28 Color toner carousel 29 Color toner cartridges 30 Delivery roller(s) EN Introduction 137 - HP 8550mfp | Service Manual - Page 140
are two methods used to create color. The subtractive process (which is used in this printer) and the additive process (which is used in monitors and television). Subtractive color theory The subtractive color theory deals with mixing color pigments (such as those found in toner, ink, and paint - HP 8550mfp | Service Manual - Page 141
Half-toning Half-toning (also called dithering) is a method used to distribute color pigment to create a full spectrum of color. Because this printer places dots of toner on a page to create an image rather than physically mixing the color (like paint), the dots are distributed in selected patterns - HP 8550mfp | Service Manual - Page 142
, and green. Adding various levels of these colors, which are generated by a light source (such as a color monitor), produces all other colors. Mixing equal amounts of the additive primary colors produces the colors indicated in table 30. Table 30. Additive color mixing Mix equal amounts of... To - HP 8550mfp | Service Manual - Page 143
Image formation Figure 24 and figure 25 give an overview of the image formation process. Figure 24. Image formation EN Image formation 141 - HP 8550mfp | Service Manual - Page 144
Figure 25 shows the simultaneous processes of image formation and paper pick-up that occur during the electrostatic latent image formation block. Figure 25. Electrostatic latent image formation block Note In the following sections, the text is numbered to match each of the numbered steps in the - HP 8550mfp | Service Manual - Page 145
and black-and-white laser imaging is that the color image is created with multiple layers. This printer contains four toner cartridges (cyan, magenta, yellow, and black). The electrostatic latent image formation block consists of three steps for forming the image on the imaging drum. At the end of - HP 8550mfp | Service Manual - Page 146
are applied to the primary charging roller to create uniform negative potential charge on the drum surface. Figure 27. Primary charging of imaging drum 3. Laser beam exposure When the laser beam scans the imaging drum surface, the charge on the exposed area is decreased. This area then forms the - HP 8550mfp | Service Manual - Page 147
on the imaging drum. The three color cartridges are brought into contact with the imaging drum when the carousel rotates. The black toner cartridge is set separately, and is always in contact with the imaging drum. When the area on the imaging drum exposed by the laser beam nears the developing - HP 8550mfp | Service Manual - Page 148
transfer A positive DC bias is applied to the transfer drum during printing to transfer the toner that is on the imaging drum to the transfer drum. This process occurs in sequence for the four colors (yellow, magenta, cyan, black). For full-color printing, as the transfer steps proceed for the four - HP 8550mfp | Service Manual - Page 149
applied to the post charging unit to add the appropriate bias to the toner that is on the transfer drum and to increase the efficiency of the secondary transfer. The post charging unit is turned on during the yellow toner primary transfer as well as after the entire image is formed. During the - HP 8550mfp | Service Manual - Page 150
jam, negative DC bias is applied to the transfer belt to transfer any residual toner from the transfer belt. The residual toner moves back to the transfer drum, and is then collected in the waste toner case in the imaging drum. Figure 31. Secondary transfer 148 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 151
8. Separation The paper is separated from the transfer drum because of the paper's elasticity. When duplex printing or overhead transparency (OHT) printing is performed, an AC bias is applied to the transfer charger. In - HP 8550mfp | Service Manual - Page 152
by the cleaning roller press solenoid (SL1). When contact is made, positive bias is applied to the cleaning roller to charge the toner on the transfer drum surface positive. After the charging is complete, the bias is turned off and the cleaning roller press cam separates the cleaning roller from - HP 8550mfp | Service Manual - Page 153
on the transfer drum is positive. Because the charge on the residual toner is made positive by the transfer drum cleaning roller, the toner moves from the transfer drum to the imaging drum, where it will be removed during imaging drum cleaning. Figure 34. Transfer drum cleaning EN Image formation - HP 8550mfp | Service Manual - Page 154
primary transfer, not all of the toner on the imaging drum is transferred to the transfer drum, leaving some toner on the imaging drum surface. Also, additional toner is placed on the imaging drum surface when the transfer drum is cleaned. 11. Imaging drum cleaning To prepare for the next printing - HP 8550mfp | Service Manual - Page 155
placed on the paper during transfer adheres to the paper by static electricity, and a light touch will smear the image. During fusing, the four toner colors are melted on the paper to create a permanent image. 12. Fusing The surfaces of the upper and lower fusing rollers are coated with silicone - HP 8550mfp | Service Manual - Page 156
than a stored value in the controller board, DRUM ERROR / REPLACE DRUM KIT is reported on the printer control panel. The controller board writes the data into the imaging drum cartridge memory. The printer is still able to print after the waste toner full warning. The controller board counts the - HP 8550mfp | Service Manual - Page 157
stops the printer and signals DRUM LIFE OUT / REPLACE DRUM KIT. Printing cannot continue without a new imaging drum being installed. If the imaging drum cartridge memory fails, a warning will be displayed on the printer control panel. Printing can continue until the waste toner sensor indicates - HP 8550mfp | Service Manual - Page 158
by the TONER LOW setting on the printer control panel (see page 88). Printing can continue after the fuser life out signal, but print quality might be degraded. Color toner level detection The color toner level sensor (PS621) detects the toner level in the color toner cartridge. PS621 consists - HP 8550mfp | Service Manual - Page 159
not reach the light receiver, the controller board signals color toner cartridge failure to the formatter and stops the printer. Also, the printer checks for the cartridge pressure when the power switch is turned on, or right after any cover is opened or closed. EN Consumable detection mechanisms - HP 8550mfp | Service Manual - Page 160
Color toner lever detection The printer has a color toner lever sensor (PS1902) to prevent toner cartridge setup failure. This sensor consists of a light receiver and a light emitter. If the color toner lever is set incorrectly, the light from the light emitter is reflected by the color toner lever - HP 8550mfp | Service Manual - Page 161
black toner cartridge has no toner. The black toner cartridge is detected by the black toner cartridge switch (SW644) in the printer. the secondary transfer bias, the transfer drum cleaning bias, and the transfer charger bias. Performs a color calibration if the environmental change is great - HP 8550mfp | Service Manual - Page 162
board uses this information to control appropriate developing bias and primary charging bias values to stabilize density of each color. ( printer is revived from Power Save (if Power Save has been on for more that 30 minutes) When a toner cartridge is installed When an imaging drum cartridge is - HP 8550mfp | Service Manual - Page 163
transfer, the controller board activates the transfer belt press clutch (CL4). The transfer belt is normally away from the transfer drum, except while pushed against the transfer drum during secondary transfer. When the secondary transfer is complete, the transfer belt is removed from the transfer - HP 8550mfp | Service Manual - Page 164
press cam presses the cleaning roller, and the cleaning roller presses against the transfer drum. When the transfer drum cleaning and secondary transfer are complete, the controller board sets the SL1 off of the home position flag (also the black toner 162 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 165
yellow cartridge stop position where the printer is ready for yellow development. The yellow toner cartridge is facing the imaging drum. Figure button while replacing the color toner cartridge, the carousel begins to rotate, then stops in the color toner cartridge fetch position. The carousel - HP 8550mfp | Service Manual - Page 166
the AC input voltage to supply the DC power sources, +24VB and +5V, on which the printer operates. The +24V source feeds the various motors, solenoids, and exhaust fans within the printer, while the +5V source feeds the controller board and image processor. High-voltage power supply/ Separation - HP 8550mfp | Service Manual - Page 167
of +24 UH. Additionally, the sensors, carousel motor, and toner cartridge motor are turned off. After the fuser cools down, all fans are also turned off. When the printer receives the "wake up" command from the formatter board, the printer leaves Power Save mode and resumes normal operation. High - HP 8550mfp | Service Manual - Page 168
use. Table 31. Fusing temperatures Target temperature Color mode Number of sheets Full color Problems in the fuser can be detected in the following three circuits: Controller board. If the fuser fuser heaters. From there, the formatter assesses the fusing heater failure and signals the printer - HP 8550mfp | Service Manual - Page 169
power supply circuit The printer contains three high-voltage PCAs (shown in figure 46) that are directly controlled by the controller board: Developer/imaging drum bias supply, which controls: • cartridge motor (M3) • imaging drum bias • black developing bias • color developing bias High-voltage - HP 8550mfp | Service Manual - Page 170
Developer/imaging drum bias supply High-voltage power supply Figure 46. High-voltage power supply circuit 168 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 171
the voltage differential signals are converted to a single laser drive signal (the internal signal of the laser/scanner unit) in the laser driver PCA, which turns the laser diode on and off and generates the modulated laser beam. The modulated laser beam is aligned by the collimator lens and the - HP 8550mfp | Service Manual - Page 172
Figure 47. Laser/scanner If the laser/scanner motor does not reach operating speed within seven seconds of rotation, then the laser/scanner motor lock detection circuit generates a scanner motor failure, and the laser/ scanner motor stops. 170 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 173
and heaters Table 32. Printer motor and heater names and descriptions Name M1 M2 M3 M4 M5 Description Carousel motor Drum motor Cartridge motor Main motor Pick-up motor Name FM1 FM2 FM3 HU HL Description Fan 1 motor Fan 2 motor Fan 3 motor Upper fuser heater Lower fuser heater EN Mechanical - HP 8550mfp | Service Manual - Page 174
Carousel motor (M1) The carousel motor (M1) is a two-phase stepping motor, and rotates the carousel. The motor operates at low and normal speeds depending on the printer function (such as sensing toner cartridges or printing). Figure 49. Carousel motor (M1) 172 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 175
stepping motor, and drives the transfer drum and the imaging drum. For overhead transparencies and glossy or heavy media, the motor rotates at low speed (OHT mode: 1/4 speed rotation; glossy and heavy media: 1/3 speed rotation). The speed of the media through the fuser is identical to the speed at - HP 8550mfp | Service Manual - Page 176
M3) is a two-phase stepping motor, and drives the black and color toner cartridge developing cylinders. The motor rotates in the normal direction for color toner development, then the motor reverses for black toner development. The developer gear drive assembly and its associated clutches engage the - HP 8550mfp | Service Manual - Page 177
Main motor (M4) The main motor (M4) is a three-phase, eight-pole, brushless motor. This motor drives the rollers related to pick-up, feeding, fusing, and delivery. This motor also drives the transfer belt press drive cam and cleaning roller press drive cam. The controller board switches the motor - HP 8550mfp | Service Manual - Page 178
-up rollers for trays 2 and 3. During tray 2 paper pick-up, M5 is rotated at normal speed. During tray 3 pick-up, normal speed reverse rotation is used. Figure 53. Pick-up motor (M5) 176 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 179
Fan motors (FM1, FM2, and FM3) The printer contains three exhaust fans, all of which use DC brushless motors. Table 33 describes when each of the fans operates and at what speed each operates. Table 33. Fan operation Turn printer on Standby Printing Power Save or Power Save or power off - HP 8550mfp | Service Manual - Page 180
Paper path Figure 54 shows the printer paper path. Figure 54. Paper path 178 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 181
will match the top of the image on the transfer drum. After that, the paper is fed through the transfer transparencies through the printer driver or by selecting OHT as the media type at the printer control panel. reception units. When a transparency is used, the light emitted from the light emitter - HP 8550mfp | Service Manual - Page 182
picked up, the light from the light emitter is transmitted inside the printer and does not reach the light receiver. The controller board signals image. The tray 2 last-page detection prevents the imaging drum and the transfer drum from getting dirty by detecting that no paper is available before - HP 8550mfp | Service Manual - Page 183
Figure 55. Tray 2 and 3 pick-up 1 Pick-up motor drive signal M4 Main motor 2 Feed roller clutch drive signal M5 Pick-up motor 3 Tray pick-up solenoid drive signal SL3 Tray pick-up solenoid 4 Registration roller clutch drive signal CL1 Registration roller clutch 5 Main motor drive signal CL2 - HP 8550mfp | Service Manual - Page 184
by the separation pad, then sent into the printer. Operation after transmission is the same as for paper width when the user adjusts the media width guides, which moves the slide resistance connected with the size drum and the transfer drum from getting dirty. 182 Chapter 5 - Theory of operation - HP 8550mfp | Service Manual - Page 185
Figure 56. Tray 1 pick-up 1 Registration roller clutch drive signal 2 Main motor drive signal 3 Registration roller paper detection signal 4 Tray 1 pick-up clutch drive signal 5 Tray 1 paper detection signal 6 Lifting plate position detection signal 7 Lifting plate solenoid drive signal 8 Tray 1 - HP 8550mfp | Service Manual - Page 186
Sensors, switches, clutches, and solenoids The following figures and tables illustrate and describe the sensors, switches, clutches, and solenoids in the printer paper path. Figure 57. Printer sensors 184 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 187
cover sensor Tray 3 sensor Tray 2 sensor Tray 3 paper-level sensor 2 Tray 3 paper-level sensor 1 Tray 2 paper-level sensor 2 Tray 2 paper-level sensor 1 Tray 3 paper-out sensor Tray 2 paper-out sensor Tray 1 paper sensor Lifting plate position sensor OHT sensor 1 OHT sensor 2 Color toner cartridge - HP 8550mfp | Service Manual - Page 188
Figure 58. Printer switches 186 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 189
Table 36. Printer switch names and descriptions Name SW1 SW201 SW202 SW641 SW642 SW644 SW671 SW672 SW673 SW1601 SW1602 SW1603 SW1604 SW1601 SW1602 SW1603 SW1604 Description Power switch Test-print switch Reset switch Right cover switch Imaging-drum switch Black toner cartridge switch Delivery - HP 8550mfp | Service Manual - Page 190
Switch functionality The following table describes the functionality of the paper-size switches in the printer. Table 37. Tray 2 and Tray 3 paper-size detection Paper size Paper-size detection switches SW1601 SW1602 SW1603 A3 Off On Off A4 (horizontal) Off Off - HP 8550mfp | Service Manual - Page 191
Figure 59. Printer clutches and solenoids Name CL1 CL2 CL3 CL4 SL1 SL2 Description Registration roller clutch Feed roller clutch Tray 1 pick-up roller clutch Transfer belt press - HP 8550mfp | Service Manual - Page 192
the fuser and the face-up and facedown delivery rollers are driven by the main motor (M4). Paper separated from the transfer drum is fed into the fuser and the fuser. The printer has a left (face-up) output bin and a top (face-down) output bin, and diverts the media to the output bins using the face - HP 8550mfp | Service Manual - Page 193
Figure 60. Fusing and delivery unit 1 Left (face-up) output bin solenoid drive signal 2 Top (face-down) output bin delivery detection signal 3 Top (face-down) output bin paper full detection signal 4 Fusing delivery detection signal 5 Main motor (M4) drive signal PS10 Top (face-down) output bin - HP 8550mfp | Service Manual - Page 194
stops printing and signals a jam condition to the formatter board. Printer timing The formatter PCA and controller board PCA share information during the printer operation. This information consists of printer status, command, and dot-image data. Figures 61 through 66 show the timing of different - HP 8550mfp | Service Manual - Page 195
Figure 61. EN Timing chart for WAIT period (1 of 2) Printer timing 193 - HP 8550mfp | Service Manual - Page 196
Figure 62. Timing chart for WAIT period (2 of 2) 194 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 197
Figure 63. EN Timing chart, printing full-color letter-sized page (1 of 2) Printer timing 195 - HP 8550mfp | Service Manual - Page 198
Figure 64. Timing chart, printing full-color letter-sized page (2 of 2) 196 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 199
Figure 65. EN Timing chart, printing full-color 11-by-17-inch page (1 of 2) Printer timing 197 - HP 8550mfp | Service Manual - Page 200
Figure 66. Timing chart, printing full-color 11-by-17 inch page (2 of 2) 198 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 201
through the paper path to print on the front side. The duplexer supports variable engine input speeds. 2,000-sheet input unit The 2,000-sheet input unit is a multi-speed high-capacity device that feeds paper to the printer. The 2,000-sheet input unit also automatically senses the paper size. Power - HP 8550mfp | Service Manual - Page 202
Sensors, switches, clutches, and motors Figure 67 and the table below illustrate and describe the sensors, switches, clutches, and motors on the 2,000-sheet input unit. 1 9 10 11 2 12 3 13 4 14 5 15 6 16 17 7 8 Figure 67. 2,000-sheet input unit sensors, switches, clutches, and motors - HP 8550mfp | Service Manual - Page 203
paper size is detected by switches SW701 through SW704. When the EPH controller board on the printer sends an input command to the controller board PCA on the 2,000-sheet input unit, the paper deck driver runs the pick-up motor to rotate the pick-up, feed, and separation rollers. As the - HP 8550mfp | Service Manual - Page 204
Switch functionality The following tables describe the functionality of the paper-quantity and paper-size switches in the 2,000-sheet input unit. Table 38. Paper-quantity detection switches SW601 Off On On Off SW602 Off Off On On Remaining paper 100% 75% 50% 25% Table 39. Paper-size detection - HP 8550mfp | Service Manual - Page 205
rollers, the number of sheets decreases. Once the paper stack decreases to a certain level, the PS34 sensor registers a low condition. Then the paper deck driver turns on the lifter motor again and lifts the paper stack until the PS34 sensor registers sufficient paper in the tray. EN 2,000-sheet - HP 8550mfp | Service Manual - Page 206
Paper path Figure 68 illustrates the paper path components in the 2,000-sheet input unit. 5 2 1 34 6 7 8 Figure 68. 2,000-sheet input unit paper path 1 Lifting plate 2 Paper stack 3 Pick-up roller 4 Feed roller 5 Upper VTU rollers 6 VTU 7 Lower VTU rollers 8 Separation roller 204 Chapter 5 - - HP 8550mfp | Service Manual - Page 207
printer stops printing. Job separator mode - Each print job (or copy, if printing multiple original copies) is placed in a separate bin. All multi-bin mailbox bins are used the top facedown bin. This process is seen in the printer software as one logical bin. Virtual stacker mode - Printed - HP 8550mfp | Service Manual - Page 208
HP network configuration utility, such as the HP JetAdmin software or the HP LaserJet utility for the Macintosh. Additionally, on all workstations that print to the printer, the printer driver scan and will send an error message to the printer control panel. 206 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 209
-bin mailbox is handled through the EPH controller board on the printer. The information coming from the EPH controller board is carried by the C-link cables that connect the EPH controller board PCA to all the devices that support the C-link protocol. Figure 69 shows the C-link connections. Figure - HP 8550mfp | Service Manual - Page 210
Sensors, switches, motors, and controller board PCA Figure 70 and table 40 illustrate and describe the multi-bin mailbox sensors, switches, motors, and controller board PCA. 10 1 11 2 12 13 3 4 5 14 6 7 15 8 9 Figure 70. Multi-bin mailbox sensors 208 Chapter 5 - Theory of operation EN - HP 8550mfp | Service Manual - Page 211
sensor PSExit1 Paper-delivered-to-head sensor M4 Ejector motor Controller board PCA Receiving paper The printer delivers paper to the multi-bin mailbox through the face-up delivery slot (input paper guide) at a rate of 107 mm per second. Paper arrival is sensed by the PSEntry sensor, which - HP 8550mfp | Service Manual - Page 212
. Multi-bin mailbox paper path 14 15 17 16 18 19 1 Face-up bin 2 Delivery head motor 3 Blind cover 4 Bin 1 5 Face-down bins 6 Bin 8 7 Controller board PCA 8 Flipper assembly 9 Input paper guide 10 Home position 11 Delivery head line 12 Metal tape 13 Delivery head assembly 14 Eject rollers 15 - HP 8550mfp | Service Manual - Page 213
3,000-sheet stapler/stacker Device configuration The HP 3,000-sheet stapler/stacker and the HP 3,000-sheet stacker attach to printers' left sides. 3,000-sheet stapler/stacker Set the default offset action and default stapler action at the printer control panel under Configuration of Stkr. The - HP 8550mfp | Service Manual - Page 214
on. The printer's paper handling controller sends a power-on signal to the power supply through the controller PCA. The power supply provides +26 V (volts) for motors and +5 V for sensors and controller electronics. The power supply is also activated when the controller PCA is set to service mode - HP 8550mfp | Service Manual - Page 215
jam) • paper jammed before entering the flipper (when the printer sends a message that pages are being sent to the stapler/ clearing a jam) • paper jammed in the last part of flipping (FLExit never activated) • paper jammed entering module (Exit never activated) EN 3,000-sheet stapler/stacker 213 - HP 8550mfp | Service Manual - Page 216
device receives paper from the printer at different speeds-106, 117, or 147 mm/second-depending on the printer in use. Flipper Paper arrival is them to the stapler bin (sensed by ACExit). Offset module (stacker ONLY) The offset module collects and registers print jobs/mopies from the flipper (sensed - HP 8550mfp | Service Manual - Page 217
sensor (FLEntry) Flipper entry sensor 1 (FLEntry1) Face-down paper path Path through accumulator Interlock switch Paper input from the printer Flipper Flipper exit sensor (FLExit) Accumulator exit sensor (ACExit) Gear wheel sensor (GWSens) Accumulator Stapler/carriage Controller PCA Power - HP 8550mfp | Service Manual - Page 218
(FLEntry) Flipper entry sensor 1 (FLEntry1) Face-down paper path Path through offset module Interlock switch Paper input from the printer Flipper Flipper exit sensor (FLExit) Exit sensor (Exit) Offset module Figure 74. Stacker paper path and sensors Controller PCA Power supply 216 Chapter - HP 8550mfp | Service Manual - Page 219
and covers 225 Front covers and panels 228 Top cover assembly 232 Left covers and doors 234 Right covers and doors 238 Rear cover 243 Top assemblies 245 Control panel 246 Laser/scanner unit 247 Face-down output assembly 249 Front assemblies 251 Toner lock sensor and color cartridge sensor - HP 8550mfp | Service Manual - Page 220
stacker/3,000-sheet stacker 253 Formatter board 254 Internal printer hard disk (DN model 256 Feeder assembly 257 Face-up solenoid 258 Face-up 287 Post charger HV module assemblies 288 Cleaning roller HV module assemblies 291 Main relay PCA 293 Drum/cartridge drive assembly 294 Separation - HP 8550mfp | Service Manual - Page 221
2,000-sheet input unit 298 Front cover 299 Back cover 300 Left cover 301 Vertical transfer unit 302 Right cover 304 Tray 4 305 Paper pick-up assembly 306 Controller PCA 307 Front LED PCA assembly 308 Power supply 309 Main drive assembly 310 Paper-size - HP 8550mfp | Service Manual - Page 222
Multi-bin mailbox 314 Front and back covers 315 Top cover 316 Power supply 317 Paper bins and blind cover 318 Flipper assembly 319 Delivery head position motor 321 Transport belt motor 322 Input paper guide 323 Metallic tape and housing assembly 325 Controller PCA 327 Anti-curl strings - HP 8550mfp | Service Manual - Page 223
EN Chapter contents 221 - HP 8550mfp | Service Manual - Page 224
power cord before servicing the printer. Failure to follow this instruction could result in severe injury. Never operate or service the printer with the protective cover removed from the scanner assembly. The reflected beam, although invisible, can damage your eyes. The sheet-metal parts can have - HP 8550mfp | Service Manual - Page 225
CAUTION Required tools The following tools are needed to service the printer: Phillips #1 magnetized screwdriver, 6-inch (152-mm) shaft Phillips #2 magnetized screwdriver, 6-inch (152-mm) shaft T-10, T-15, and T-20 Torx driver, 6-inch (152-mm) shaft Flat-blade #2 screwdriver Small pair of - HP 8550mfp | Service Manual - Page 226
procedures. Color toner cartridges Transfer charger Black toner cartridge Imaging drum Air filters Transfer drum Transfer belt Cleaning roller Charcoal filter Fuser Paper rollers The printer keeps track of use on some of its user-replaceable parts. Because maintenance - HP 8550mfp | Service Manual - Page 227
Front 4 5 6 7 8 Right Figure 75. Orientation of printer and accessories: top, front, and right 1 Top cover assembly 2 Front cover 3 Front right cover 4 Right upper cover assembly (includes the right upper door) 5 Right cover subassembly 6 Right lower cover assembly (includes the right lower door - HP 8550mfp | Service Manual - Page 228
3 1 4 5 2 Rear Left Figure 76. Orientation of printer and accessories: rear and left 1 Exhaust fan cover 2 Rear cover 3 Left upper cover (includes the left upper door) 4 Left rear cover 5 Left lower cover 226 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 229
frame 1 Remove two screws (callout 1) from the attachment cover on the left side of the printer to release the attachment cover. 2 Remove two screws (callout 2) from the attachment bracket. 12 2 Figure 77. Attachment bracket, HP Color LaserJet 8550 MFP printer 3 On each side at the bottom of the - HP 8550mfp | Service Manual - Page 230
2 12 Figure 79. Note Removing the front cover 3 Remove one screw holding the cover (callout 2). 4 Open the cover to approximately a 45-degree angle and lift it up to remove it. Callout 3 is the tag that shows engine settings; sections of Chapter 6, "Troubleshooting" refer to the tag. 228 Chapter - HP 8550mfp | Service Manual - Page 231
Removing the front right cover 1 Open the front door. 2 Remove one screw in the upper right-hand side that holds the front right cover on (callout 1). 12 Figure 80. Front right cover 3 Pull the cover off. EN Doors and covers 229 - HP 8550mfp | Service Manual - Page 232
panel (callout 1). 2 12 32 42 12 Figure 81. Inside left panel 4 Remove the waste toner tray cover (callout 2) by releasing the tab on the right side of the cover with a small screwdriver. 5 Remove the waste toner tray. 6 Open the left lower door to disengage the interlock. 7 Swing both the lower - HP 8550mfp | Service Manual - Page 233
Removing the filler panel for tray 2 (HP Color LaserJet 8550 base model) 1 Open the front cover. 2 Release the tab at the top, towards the right, of the filler panel and rotate the top with a tray 2, remove the screw and the bracket before attempting to install a tray 2. EN Doors and covers 231 - HP 8550mfp | Service Manual - Page 234
assembly 1 Remove the front right cover (see page 229). Leave the front door open. 2 Open the left door and loosen the two screws (callout right door and loosen the two screws (callout 2). 2 Figure 84. Screws behind right door 4 Open the front cover. 232 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 235
5 Lift the cover up and unplug the connector (callout 3) at the rear of the cover. 32 Figure 85. Connector on top cover 6 Remove the top cover assembly. EN Doors and covers 233 - HP 8550mfp | Service Manual - Page 236
Left covers and doors Removing the left rear cover 1 Open the left upper door. 2 Support the door and squeeze the prong with needle-nose pliers to unhook the strap holding the door to the left rear cover (callout 1). 12 Figure 86. Left door and strap 234 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 237
3 Remove 11 screws (callout 2). 2 2 Figure 87. Screws on left rear cover 4 Pull the cover to the left and off. EN Doors and covers 235 - HP 8550mfp | Service Manual - Page 238
Removing the left upper cover 1 Remove the left rear cover (see page 234). 2 Remove two screws on the rail (callout 1, one screw is on the left side of the cover and the other is located inside the front cover). 12 Figure 88. Screws on upper left door 3 Remove the door. 236 Chapter 6 - Removal - HP 8550mfp | Service Manual - Page 239
. 2 Push the spring-loaded stopper hinges (callout 1) towards the printer and down to release them. 12 Figure 89. Stopper hinges on lower left cover 3 Move the cover to a 45-degree angle and lift the right side out. 4 Slide the cover to the left and up to release the left side. EN Doors and - HP 8550mfp | Service Manual - Page 240
cover assembly Tray 1 is part of the right upper door. Take the tray off and save it if you are replacing the whole assembly (see page 261). The new assembly does not include the tray. 1 Remove the rear cover that lead through the printer frame to the right upper cover (callout 1). Two connectors - HP 8550mfp | Service Manual - Page 241
5 With needle-nose pliers, remove the e-ring from the hinge (callout 2) on the left side of the door. 2 Figure 91. E-ring 6 Remove the front right cover (see page 229). 7 Rotate the plastic tab (located on the left hinge) in an upward direction to a 90-degree angle. 8 Lift the door slightly to - HP 8550mfp | Service Manual - Page 242
Note Note Removing the right cover subassembly Use this procedure if you want to separate the right cover subassembly from the right upper cover. 1 Open the right upper cover assembly slightly. 2 Pull the right side of the subassembly slightly to the right and pull outward on the right side to snap - HP 8550mfp | Service Manual - Page 243
Removing the right rear cover 1 If you have a 2,000-sheet input unit, open the VTU. 2 Remove one screw (callout 1). 12 Figure 93. Right rear cover 3 Pull the bottom of the cover out and then down to remove the cover. EN Doors and covers 241 - HP 8550mfp | Service Manual - Page 244
2 If you have a 2,000-sheet input unit, open the VTU. 3 Remove the right rear cover (see page 241). 4 Remove four screws on the right lower cover in place (callout 1). 12 Figure 94. Screws on the right lower cover 5 Unfasten the holding strap on the right. 6 Remove tray 2 and tray 3, and release - HP 8550mfp | Service Manual - Page 245
: a Release two thumb screws (callout 1) to disconnect the video I/O connector. b Remove three screws (callout 2) from inside the opening; the plate remains attached to the rear cover. 12 2 Figure 95. Plate, HP Color LaserJet 8550 MFP printer EN Doors and - HP 8550mfp | Service Manual - Page 246
door. 5 Remove three screws in the sheet metal tab (callout 2). 6 Remove the right rear cover (see page 241). 7 Remove two screws (callout 3). 8 Remove 13 screws on the rear cover (callout 4). Two screws are holding the cover to the hinges at the bottom. It is not necessary to remove these screws - HP 8550mfp | Service Manual - Page 247
Top assemblies Gain access to the following assemblies from the top of the printer: control panel laser/scanner unit face-down output assembly EN Top assemblies 245 - HP 8550mfp | Service Manual - Page 248
upside down. 3 Remove four screws attaching the control panel to the top cover (callout 1). 2 12 Figure 97. Bottom of the control panel 4 Remove three screws from the bar on the bottom of the control panel that is holding - HP 8550mfp | Service Manual - Page 249
Remove the top cover assembly (see page 232). 2 On HP Color LaserJet 8550 printer models, remove four screws, two on each side (callout 1 shows two of them), from the laser/ scanner shield and lift the shield out of the printer (the shield is not present on HP Color LaserJet 8500 printer models). 12 - HP 8550mfp | Service Manual - Page 250
3 Remove four screws (callout 1) from the laser/scanner unit. 12 2 Figure 99. Scanner unit 4 Release the wires from the cable stay. 5 Unplug the two connectors (callout 2). 6 Gently remove the laser/scanner unit and place it in an ESD pouch. 248 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 251
Face-down output assembly 1 Remove the top cover assembly (see page 232). 2 Remove the left rear cover (see page 234). 3 Remove the left upper cover (see page 236) 4 On the top of the printer, remove the black airflow vent by releasing the cut tab (callout 1) and lifting the vent off. 12 Figure 100 - HP 8550mfp | Service Manual - Page 252
7 Pull the rail away from the chassis. 8 Remove two screws (callout 4). 42 Figure 102. Face-down output assembly 9 Lift the right side of the assembly, slide the assembly to the left, and lift it out of the chassis. 250 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 253
access to the following assemblies from the front of the printer: toner lock sensor color cartridge sensor subrelay PCA Toner lock sensor and color cartridge sensor 1 Remove the inside left panel (see page 230). 2 Remove one screw on the toner lock sensor (callout 1). 12 2 32 42 Figure 103 - HP 8550mfp | Service Manual - Page 254
Subrelay PCA 1 Remove the inside left panel (see page 230). 2 Remove the five connectors on the subrelay PCA (callout 1). 3 Remove four screws on the subrelay PCA (callout 2). 2 12 12 Figure 104. Subrelay PCA 252 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 255
the left side of the printer: formatter board internal printer hard disk feeder assembly face-up printer. 4 Holding the paper output accessory by the handle on the top and by the main body towards the bottom, pull the accessory away from the printer. 5 Push down on the end of the guide - HP 8550mfp | Service Manual - Page 256
or replaced, remove the hard drive and retain it to reattach to the formatter board later. 1 Print a configuration page if the printer is able to generate one (see page 415). Use this page to reset the NVRAM values that will be lost if the formatter board is replaced. 2 Loosen the two finger - HP 8550mfp | Service Manual - Page 257
count (percentage of life remaining) • Fuser kit count (percentage of life remaining) • Engine settings The last two digits of the engine settings might vary from those found on the sticker inside the front cover. This difference is due to check sum variation and is acceptable. For information on - HP 8550mfp | Service Manual - Page 258
, all data stored on the hard disk will be lost. Download fonts and other information as necessary. 1 Remove the formatter board from the printer (see page 254). 2 Unplug one connector (callout 1). 12 Figure 106. Connector on formatter board 3 On the other side of the formatter board, release - HP 8550mfp | Service Manual - Page 259
upper door. 1 Open the front door, and the left lower cover. 2 Remove the left rear cover (see page 234). 3 Remove the left upper cover (see page 236). 4 Remove six screws (callout 1). 12 Figure 108. Feeder assembly 5 Lift the feeder assembly up and out. Notes about reinstalling: Verify that - HP 8550mfp | Service Manual - Page 260
-up solenoid is below the carousel stop. 1 Remove the feeder assembly (see page 257). 2 Remove the face-up output bin. 3 Remove the formatter board and formatter pan (see page 254 and page 272). 4 Remove one screw inside the back of the printer (callout 1). 32 12 Figure 109. Face-up solenoid (1 of - HP 8550mfp | Service Manual - Page 261
5 Lift the face-up solenoid up to release the tab and pull out to remove the solenoid (callout 2). 2 Figure 110. Face-up solenoid (2 of 2) Notes about reinstalling: Ensure that the plastic arm from the solenoid is engaged under the delivery drive swing arm (callout 3, figure 109). EN Left - HP 8550mfp | Service Manual - Page 262
Face-up exit assembly The face-up exit assembly is located on the left lower cover. 1 Remove the left lower cover (see page 237). 2 Remove six screws (callout 1). 12 Figure 111. Screws on the face-up exit assembly 3 Remove the stopper hinges by popping the peg - HP 8550mfp | Service Manual - Page 263
Gain access to the following assemblies from the right side of the printer: tray 1 pick-up roller registration roller assembly paper photo sensors density sensor paper pick-up assembly tray 1 pick-up assembly Tray 1 Tray 1 is part of the right upper door. Take the tray off and save - HP 8550mfp | Service Manual - Page 264
pull to the left to remove the roller (callout 1). 12 2 Figure 113. Pick-up roller Note The figure above shows the inside of an HP Color LaserJet 8500 printer. The black plastic piece (callout 2) is eliminated on HP Color LaserJet 8550 printer models. 262 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 265
assembly is located inside the right upper door under the transfer belt. 1 Open the front door and the right upper door. 2 Remove the transfer drum. 3 Remove the transfer belt. 4 Lift the paper diverter and remove two screws (callout 1). 12 Figure 114. Registration roller assembly (front) EN 263 - HP 8550mfp | Service Manual - Page 266
5 Remove two screws on the back of the assembly (callout 2). Hint You might need to use a shorter screwdriver to get the back screws out. 2 Figure 115. Registration roller assembly (back) 264 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 267
cover over the connectors on the right side of the registration roller assembly. 7 Unplug the innermost connector on the right side (callout 3). 32 Figure 116. Connectors on registration roller assembly 8 Remove one screw from the green knob on the front of the printer and are used to sense - HP 8550mfp | Service Manual - Page 268
sensor is located on the right upper door. 1 Open the right upper door. 2 With a flat screwdriver, release the six tabs on the sensor cover (callout 1). 2 12 Figure 117. Density sensor 3 Remove three screws from the sensor (callout 2). 4 Unplug one connector and remove the sensor. 266 Chapter - HP 8550mfp | Service Manual - Page 269
Paper pick-up assembly The paper pick-up assembly is located inside the right upper cover assembly. 1 Remove trays 2 and 3. 2 Remove the right upper cover assembly (see page 238). 3 Remove the right lower cover assembly (see page 242). 4 Remove four screws, one in each corner of the paper pick-up - HP 8550mfp | Service Manual - Page 270
the right upper door. 2 Remove the screw on the right side of the assembly (callout 1). . 2 12 Figure 119. Tray 1 pick-up assembly (1 of 2) 3 Remove the cover on the right side of the assembly (callout 2). 268 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 271
the controller board, and two connectors are inline connectors. It might be easier to disconnect the connectors from the rear of the printer and pull the wires through the printer frame than to unplug the connectors from the right upper door. . 32 42 32 Figure 120. Tray 1 pick-up assembly (2 of - HP 8550mfp | Service Manual - Page 272
123 Figure 121. Rear of printer with cover removed 1 Developer/imaging drum bias 5 Post charger high-voltage supply (shown in two parts, the (HV) module upper part is eliminated in all 6 Controller board HP Color LaserJet 8550 printer models) 7 Sheet metal cover plate 2 Main relay PCA-located - HP 8550mfp | Service Manual - Page 273
12 42 2 32 52 Figure 122. Rear of printer with formatter pan removed 1 Delivery drive assembly 2 Lower air duct 3 behind the high-voltage power supply. The main gear assembly is behind the developer/imaging drum bias supply. The tray 2 and tray 3 media size sensing PCAs are located behind - HP 8550mfp | Service Manual - Page 274
Formatter pan 1 Remove the rear cover (see page 243). 2 Remove the formatter board from the formatter pan (see page 254). 3 On the back of the printer, remove two screws on the top and three on the bottom of the pan (callout 1). 12 Figure 123. Formatter pan 272 Chapter 6 - Removal and replacement - HP 8550mfp | Service Manual - Page 275
4 Remove five screws on the left side of the printer (callout 2). 2 Figure 124. Formatter pan (left side) 5 Pull the formatter pan off. EN Rear assemblies 273 - HP 8550mfp | Service Manual - Page 276
Fan 1 Fan 1 is located on the middle right side of the rear of the printer. For information about removing the fan 1 housing, see page 283 (steps 4 through 6). 1 Remove the rear cover (see page 243). 2 Unplug the fan connector from the PCA (callout 1). 12 2 32 Figure 125. Fan 1 3 Push out on the - HP 8550mfp | Service Manual - Page 277
Fan 2 Fan 2 is located on the upper right side of the rear of the printer. For information about removing the fan 2 housing, see page 283 (steps 7 through 8). 1 Remove the rear cover (see page 243). 2 Unplug one connector (callout 1). 2 12 Figure 126. Fan 2 3 Push out on the tabs on the left and - HP 8550mfp | Service Manual - Page 278
Power supply The power supply is located on the lower right side of the rear of the printer. 1 Remove the rear cover (see page 243). 2 Remove the formatter board and formatter pan (see page 254 and page 272). 3 Unplug the five connectors. 4 Release one cable stay. 5 Remove - HP 8550mfp | Service Manual - Page 279
board in an HP Color LaserJet 8550 MFP printer and includes the ECO board cable (callout 1). Compare the controller board to the same part from an HP Color LaserJet 8500 printer, in figure 129 on page 278. 12 Figure 128. Controller board, HP Color LaserJet 8550 MFP printer Note Controller board - HP 8550mfp | Service Manual - Page 280
272). 4 Unplug 25 connectors. Hint All 25 connectors are keyed. Also, it is easier to unplug the connectors before removing the screws from the PCA. 5 Remove four screws (callout 1). 2 12 Figure 129. Controller board, HP Color LaserJet 8500 6 Push the white plastic holding tab in the upper - HP 8550mfp | Service Manual - Page 281
ECO board The ECO board is located on the lower left side of the rear of the printer, below the controller board, on HP Color LaserJet GN printer models. 1 Remove the rear cover (see page 243). 2 Remove the formatter board and formatter pan (see page 254 and page 272). 3 Unplug the ECO board - HP 8550mfp | Service Manual - Page 282
Cartridge motor (M3) This motor is located to the left of fan 1. 1 Remove the rear cover (see page 243). 2 Unplug one connector (callout 1). 12 2 Figure 131. Cartridge motor 3 Remove four screws on the motor (callout 2), and pull the motor out. 280 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 283
Main motor (M4) This motor is located to the right of the controller board, behind the formatter pan. 1 Remove the rear cover (see page 243). 2 Remove the formatter board and formatter pan (see page 254 and page 272). 3 Unplug one connector. 4 Remove four screws (callout 1), and pull - HP 8550mfp | Service Manual - Page 284
Carousel motor PCA This PCA is located on the upper right side of the rear of the printer. 1 Remove the rear cover (see page 243). 2 Unplug six connectors. 3 Remove one screw (callout 1). 2 12 Figure 133. Carousel motor PCA 4 Release three tabs from the PCA (callout 2). 5 Lift the - HP 8550mfp | Service Manual - Page 285
(see page 243). 3 Remove the formatter board and formatter pan (see page 254 and page 272). 4 Remove five screws from the sheet metal cover plate and lift it off. 5 Remove four screws from the fan 1 assembly (callout 1). 32 42 2 12 Figure 134. Fans 1 and 2 housing assemblies 6 Release two cable - HP 8550mfp | Service Manual - Page 286
9 On the right side of the carousel motor, unplug one connector (callout 5). 62 52 Figure 135. Carousel motor 10 Remove four screws from the motor and lift it out (callout 6). 284 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 287
Delivery drive assembly The delivery drive assembly is located behind the fan 1 housing and the formatter pan. 1 Remove the carousel motor PCA (see page 282). 2 Remove fan 1 housing (see page 283, steps 4 through 6). 3 Remove two screws (callout 1) from the lower air duct and remove the lower air - HP 8550mfp | Service Manual - Page 288
4 Release three cable stays on the bottom of the delivery drive assembly. 5 Remove one screw (callout 3) and the gear cover. 42 52 32 Figure 137. Screws on the delivery drive assembly 6 Remove seven screws from the delivery drive assembly (callout 4). 7 Lift the assembly up and - HP 8550mfp | Service Manual - Page 289
) 1 Open the left lower cover and remove the fuser. 2 Open the right upper door and remove the transfer drum. 3 Remove the registration roller assembly 3 from the printer. 9 Remove the tray 2 rail from the front of the printer (one screw, two connectors). 10 Remove the inner cover 4 (see reference - HP 8550mfp | Service Manual - Page 290
The post charger HV module assemblies are located on the midupper of the rear of the printer. Shown in figure 139 below are the assemblies in an HP Color LaserJet 8550 printer. Compare the developer/imaging drum bias supply to the same part from an HP Color LaserJet 8500 printer, in figure 140 on - HP 8550mfp | Service Manual - Page 291
assembly (see page 232) and then remove the rear cover (see page 243). 2 Remove five screws from the sheet metal cover plate and lift it off. 3 Unplug four connectors (callout 3). 32 12 52 2 42 32 Figure 140. Developer/imaging drum bias supply 4 Release two cable stays. 5 Remove two screws on - HP 8550mfp | Service Manual - Page 292
one screw to release the wire from the open ended diode (callout 1, screw is hidden from view). 2 12 Figure 141. Post charger HV module 3 Release two cable stays. 4 Remove one screw on the top of the module (callout 2). 5 Lift the module up and out. 290 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 293
assemblies The cleaning roller HV module includes two PCAs stacked on top of each other and is located on the upper left side when facing the rear of the printer. Removing high-voltage power supply 1 Remove the rear cover (see page 243). 2 Remove the formatter board and formatter pan (see page - HP 8550mfp | Service Manual - Page 294
holes. When putting the PCA back in, be sure you do not get any wiring caught behind it. Removing cleaning roller HV module 1 Remove the rear cover (see page 243). 2 Remove the formatter board and formatter pan (see page 254 and page 272). 3 Unplug two connectors (callout 1). 2 12 Figure - HP 8550mfp | Service Manual - Page 295
relay PCA This PCA is located behind the developer/imaging drum bias supply. 1 Remove the rear cover (see page 243). 2 Remove five screws from the sheet metal cover plate and lift it off. 3 Remove the developer/imaging drum bias supply (see page 291). 4 Unplug eight connectors (callout 1). 2 12 - HP 8550mfp | Service Manual - Page 296
page 290). 2 Remove the cleaning roller HV module and the high-voltage power supply (see page 289). 3 Remove the fan 1 housing (see page 283, steps 4 through 6). 4 Release three cable stays. 5 Remove 12 screws (callout 1). 2 12 Figure 145. Drum/cartridge drive assembly 6 Lift the assembly up and - HP 8550mfp | Service Manual - Page 297
discharge high-voltage converter assemblies are located in the bottom right corner of the rear of the printer. Removing separation discharge high-voltage converter PCA 1 Remove the rear cover (see page 243). 2 Remove the formatter board and formatter pan (pages 254, 272). 3 Unplug three connectors - HP 8550mfp | Service Manual - Page 298
Tray 2 and tray 3 media-size sensing PCAs 1 Remove the rear cover (see page 243). 2 Remove the formatter board and formatter pan (see page 254 and page 272). 3 Remove the power supply (see page 276). 4 Release one - HP 8550mfp | Service Manual - Page 299
6 Open the corresponding tray. 7 Remove three screws (callout 2) and unplug one connector on each PCA to remove. 12 Figure 148. Media size sensing PCAs Note The two PCAs and wire-sensing finger assemblies are interchangeable. EN Rear assemblies 297 - HP 8550mfp | Service Manual - Page 300
2,000-sheet input unit You do not have to detach the 2,000-sheet input unit from the printer to service any of the units. The replaceable units are: front, back, left, and right covers VTU tray 4 paper pick-up assembly controller PCA front LED PCA assembly power supply main drive - HP 8550mfp | Service Manual - Page 301
tray 4 to the stops. 2 Remove the paper limit-back plate from the tray (callout 1). . 12 2 32 Figure 149. Front cover of the 2,000-sheet input unit 3 Remove four screws (callout 2). 4 Use a flat-blade screwdriver to release the plastic retaining tabs on the left- and right-front sides of the tray - HP 8550mfp | Service Manual - Page 302
the power cord and the C-link interface cables from the 2,000-sheet input unit. 2 Remove four screws (callout 1). 12 Figure 150. Back cover removal 3 Pull the cover back from the chassis. Notes about reinstalling: Make sure the tab on the lower-left corner is inserted into its alignment slot - HP 8550mfp | Service Manual - Page 303
are along the bottom edge (callout 2). 4 Pull out on the lower-left corner to release the plastic retainer tab that secures that corner of the cover to the chassis. Notes about reinstalling: Replace the left side first. Tilt the right side down and toward the chassis to place the lower retaining - HP 8550mfp | Service Manual - Page 304
Vertical transfer unit Remove the VTU to access the left side of the unit and the paper path mechanisms. 1 Unplug the power cord and the C-link interface cables from the 2,000-sheet input unit. 2 Open the VTU. 3 Rotate the two plastic safety catches on the VTU hinges towards the unit to the "open" - HP 8550mfp | Service Manual - Page 305
5 Remove two screws, one on the inner side of each safety catch. 6 Pull the door halfway closed, then lift the unit straight up to clear the metal locating tabs on the chassis. Notes about reinstalling: Before tightening the screws, ensure that the metal locating tabs are in place. WARNING! - HP 8550mfp | Service Manual - Page 306
the VTU (see page 302). 2 Remove two screws near the middle of the right cover (callout 1). 2 12 Figure 153. Right cover with VTU removed 3 Using a flat-blade screwdriver, release the plastic retaining tab on the upper-left corner of the cover (callout 2). 4 Carefully pull out on the top of the - HP 8550mfp | Service Manual - Page 307
vertical transfer unit (VTU) (see page 302). 3 Remove the left and right covers (see page 301 and page 304). 4 Remove one screw and one metal retaining tab from each side of the chassis (callout 1). 12 Figure 154. Tray 4 removal 5 Support the rear of the tray while sliding it straight out of the - HP 8550mfp | Service Manual - Page 308
-up assembly The paper pick-up assembly is located on the right side of the unit. 1 Remove the VTU (see page 302). 2 Remove the right cover (see page 304). 3 Open tray 4 to the stops. 4 Unplug three connectors (callout 1). 2 12 Figure 155. Paper pick-up assembly 5 Remove five screws (callout - HP 8550mfp | Service Manual - Page 309
Controller PCA The controller PCA is located on the back of the unit. 1 Remove the back and left covers (see page 300 and page 301). 2 Unplug 11 connectors (callout 1). 42 12 52 2 32 Figure 156. Controller PCA 3 Remove four hex screws from the two C- - HP 8550mfp | Service Manual - Page 310
Front LED PCA assembly 1 Open tray 4 halfway to the stops. 2 On the upper-left corner of the front of the chassis, remove one screw (callout 1). 12 Figure 157. Screw on front LED PCA assembly 3 Reach behind the LED PCA assembly and pull it away from the chassis. 4 Release three plastic retaining - HP 8550mfp | Service Manual - Page 311
Power supply 1 Unplug the power cord and the C-link interface cables from the 2,000-sheet input unit. 2 Remove the back and left covers (see page 300 and page 301). 3 Unplug one connector (callout 1). 2 12 Figure 159. Power supply 4 Remove two screws (callout 2). 5 Lift the power supply upward to - HP 8550mfp | Service Manual - Page 312
Main drive assembly 1 Remove the back cover (see page 300). 2 Unplug one connector from the controller PCA (callout 1). 12 2 Figure 160. Main drive assembly 3 Release two cable stays. 4 Remove one screw on - HP 8550mfp | Service Manual - Page 313
paper-size sensor assemblies: the quantity switch assembly and the paper-size switch assembly. Removing the quantity switch assembly 1 Remove the back cover (see page 300). 2 Unplug one connector from the controller PCA (callout 1). 12 2 32 Figure 161. Paper quantity switch assembly 3 Release two - HP 8550mfp | Service Manual - Page 314
Removing the paper-size switch assembly 1 Remove the back cover (see page 300). 2 Unplug one connector from the controller PCA (callout 1). 12 2 32 Figure 162. Paper size switch assembly 3 Remove one screw (callout 2) and the - HP 8550mfp | Service Manual - Page 315
Tension springs 1 Remove the left cover (see page 301). 2 Open tray 4 to the stops. 3 Inside the tray, remove one spring on the left runner and one spring on the right runner (callout 1). 12 Figure 163. Tension springs EN 2,000-sheet input tray 313 - HP 8550mfp | Service Manual - Page 316
front, back, and top covers controller PCA power supply anti-curl strings paper bins and blind cover delivery head assembly input paper guide attachment assembly metallic tape and housing assembly Hint Place the multi-bin mailbox on a table for ease in servicing the unit. - HP 8550mfp | Service Manual - Page 317
1 Remove the multi-bin mailbox from the printer. 2 For each cover, use a small flat-blade screwdriver to release the three retaining tabs that secure the cover to the frame (callout 1). 12 12 Figure 164. Front and back covers 3 Rotate the cover outward to release it from the frame. EN Multi - HP 8550mfp | Service Manual - Page 318
the upper- front side of the frame). 2 12 32 Figure 165. Top cover 3 Remove one screw that secures the LED PCA to the frame (callout 2). 4 Remove two screws close to the upper-right side (callout 3). 5 Slide the top cover to the left side of the unit, then lift it up and out - HP 8550mfp | Service Manual - Page 319
Power supply 1 Unplug one connector from the controller PCA (callout 1). 2 12 Figure 166. Power supply 2 Press the plastic retaining tabs on each side of the power supply to remove it (callout 2). EN Multi-bin mailbox 317 - HP 8550mfp | Service Manual - Page 320
outer edge of the bin to clear the retaining notch in the frame, and then pull the bin away from the frame. 2 Remove the blind cover. Figure 167. Paper bins 3 Remove each face-down bin, starting at the top and working down in sequence. Notes about reinstalling: Slide a bin into its - HP 8550mfp | Service Manual - Page 321
Flipper assembly 1 Remove all paper bins and the blind cover (see page 318). 2 Remove the front, back, and top covers (pages 315, 316). 3 Remove two screws closest to the upper-left side (callout 1). 12 32 12 Figure 168. Flipper assembly (1 of 3) 4 Hold down the jam - HP 8550mfp | Service Manual - Page 322
5 Unplug three connectors (figure 168, callout 3). 6 Use a flat-blade screwdriver to release the plastic retaining tab that secures the assembly to the top of the frame (callout our). 42 52 Figure 170. - HP 8550mfp | Service Manual - Page 323
Delivery head position motor 1 Remove the back cover (see page 315). 2 Unplug one connector (callout 1). 2 12 Figure 171. Delivery head motor 3 Remove two screws from the motor (callout 2). 4 Pull the motor away from - HP 8550mfp | Service Manual - Page 324
(see page 315). 2 Remove all paper bins and the blind cover (see page 318). 3 Release the controller PCA assembly from the bottom of the frame (see page 327, steps 1 through 7). 4 Unplug the J8 connector on the - HP 8550mfp | Service Manual - Page 325
Input paper guide 1 Remove the multi-bin mailbox from the printer. 2 Remove the face-up bin and the blind cover (see page 318). 3 Hold down the jam access door while unplugging the ground wire (callout 1). 12 Figure 173. Input paper guide (1 of 2) EN Multi-bin mailbox 323 - HP 8550mfp | Service Manual - Page 326
4 Use a flat-blade screwdriver to release the retaining tabs on the top of the input paper guide (callout 2). 32 2 Figure 174. Input paper guide (2 of 2) 5 Pull the input paper guide free of the frame while routing the ground wire through the wire access hole (callout 3). 324 Chapter 6 - Removal - HP 8550mfp | Service Manual - Page 327
Metallic tape and housing assembly 1 Remove all paper bins and the blind cover (see page 318). WARNING! The sharp edges of the metal tape can cause serious injury. When rewinding the metal tape into its housing, hold the - HP 8550mfp | Service Manual - Page 328
5 Use a flat-blade screwdriver to release the plastic retaining tabs located on of the tape to the top of the multi-bin mailbox and reinsert it into place (callout 1). Use the guide pins to reinstall the tape housing (callout 3). When the housing is correctly positioned, it will click into place - HP 8550mfp | Service Manual - Page 329
power cable (callout 1). 2 12 32 32 Figure 177. Controller PCA (1 of 2) 2 Disconnect the C-link cable (callout 2). 3 Remove all paper bins and the blind cover (see page 318). 4 Carefully lay the multi-bin mailbox on its front side. 5 Loosen one grounding screw and two self-tapping screws on - HP 8550mfp | Service Manual - Page 330
8 Unplug eight connectors (callout 5) and remove the PCA. 52 Figure 178. Controller PCA (2 of 2) 328 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 331
page 315). 2 Remove all the paper bins and the blind cover (see page 318). 3 On the lower-left side of the frame, remove two screws securing the tension springs (callout 1). 12 2 Figure 179. Anti-curl strings (1 - HP 8550mfp | Service Manual - Page 332
6 Release the upper ends of the anti-curl strings from the jam access door by pushing the retaining tabs that secure the strings to the door (callout 3). 32 Figure 180. Anti-curl strings (2 of 2) 330 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 333
page 315). 2 Remove all paper bins and the blind cover (see page 318). WARNING! The sharp edges of the metal tape can cause serious injury. When rewinding the metal tape into its housing, hold the - HP 8550mfp | Service Manual - Page 334
5 Release the flat ribbon cable from the cable clip (callout 2), and gently disconnect the cable (callout 3). 2 32 Figure 182. Delivery head assembly (2 of 4) 6 Raise the assembly to the top of the frame. 7 Hold up the assembly and remove two screws (callout 4). 42 Figure 183. Delivery head - HP 8550mfp | Service Manual - Page 335
8 Rotate the assembly clockwise while guiding the back end out of its access opening (see figure 184). 9 Release the anti-curl strings from the pulleys on each end of the assembly ( - HP 8550mfp | Service Manual - Page 336
CAUTION Interlock switch 1 Remove the back cover (see page 315). Before removing the wires from the multi-bin mailbox interlock switch, note the location of each wire. Replacing the wires incorrectly can - HP 8550mfp | Service Manual - Page 337
Diagnostic LED PCA 1 Remove the back cover (see page 315). 2 Unplug two connectors from the PCA (callout 1). 12 2 Figure 186. Diagnostic LED PCA 3 Remove one screw (callout 2). 4 Pull the PCA away from the frame. EN Multi-bin mailbox 335 - HP 8550mfp | Service Manual - Page 338
User status LED PCA 1 Remove the front cover (see page 315). 2 Disconnect the cable from the PCA (callout 1). 12 2 Figure 187. User status LED PCA 3 Remove one screw (callout 2). 4 Pull the PCA away from the frame. 336 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 339
Attachment assembly 1 Remove the controller PCA, but leave cables connected (see page 327). 2 Set the controller PCA on top of the unit (callout 1). 12 2 Figure 188. Attachment assembly 3 Remove the e-ring (callout 2). 4 Release the pivot pin that holds the attachment assembly rod to the frame. 5 - HP 8550mfp | Service Manual - Page 340
and 3,000-sheet stacker: face-up and stapler/stacker bins front, back, and foot covers stapler door assembly with label1/stacker door assembly2 controller PCA cover flipper assembly carriage assembly1 accumulator assembly1 offset module2 stapler1 controller PCA LED PCA - HP 8550mfp | Service Manual - Page 341
the bin straight up until it is released from the frame. 32 12 2 42 Figure 189. Bins removal Front cover 1 Use the TX-20 screwdriver to remove three screws (callout 1). 2 Lift the cover straight up until it is released from the product. EN 3,000-sheet stapler/stacker and 3,000-sheet stacker 339 - HP 8550mfp | Service Manual - Page 342
Back cover 1 Use the TX-20 screwdriver to remove three screws (callout 2). 2 Press and hold in the interlock switch (callout 3) while lifting the cover straight up until the cover is released from the product. 32 2 12 Figure 190. Front and back covers removal 340 Chapter 6 - Removal and replacement - HP 8550mfp | Service Manual - Page 343
it up to clear the locating pin. Repeat this step for the opposite side of the foot cover. 3 Lift up the cover and pull it away from the product. Figure 191. Foot cover removal To reinstall The cover can be difficult to replace correctly. Make sure you line up the ridges on the bottom - HP 8550mfp | Service Manual - Page 344
of the hinges are parallel to the floor and pull the door straight away from the product. Controller PCA cover (with label) 1 Use the TX-20 screwdriver to remove the upper and lower screws (callout 2) from the cover. 2 Rotate the cover to clear the tabs at the back of the product and lift the - HP 8550mfp | Service Manual - Page 345
Internal assemblies Flipper assembly 1 Remove the front and back covers. 2 At the back of the product, disconnect the flipper ribbon cable (callout 1) by pressing the black tabs on the connector to release the cable. 3 Use the TX-20 screwdriver to remove four screws (callout 2), two on each side of - HP 8550mfp | Service Manual - Page 346
4 Use both hands to grasp the assembly on each side and, with a firm tug, lift the assembly straight up to clear the tabs (callout 1; one of - HP 8550mfp | Service Manual - Page 347
Carriage assembly (stapler/stacker only) 1 Remove the front cover, the back cover, and the controller PCA cover. 2 Disconnect the ribbon cable (callout 1) from the controller PCA by pressing the black tabs to release the cable. 12 Figure 195. Carriage assembly removal (1 of 2) 3 - HP 8550mfp | Service Manual - Page 348
4 Use the TX-20 screwdriver to remove two screws (callout 1), one on each side of the assembly. 5 Lift the assembly to clear the tabs on each - HP 8550mfp | Service Manual - Page 349
(stapler/stacker only) 1 Remove the front cover, the back cover, the controller PCA cover, the flipper assembly, and the carriage assembly. While it is possible to remove the accumulator assembly without first removing the carriage assembly, HP strongly recommends that the carriage assembly be - HP 8550mfp | Service Manual - Page 350
4 Use the TX-20 screwdriver to remove four screws (callout 1), two on each side of the assembly. 12 Figure 198. Accumulator assembly removal (2 of 2) 5 Lift the - HP 8550mfp | Service Manual - Page 351
Offset module (stacker only) 1 Remove the front cover, the back cover, the controller PCA cover, and the flipper assembly. 2 Disconnect the ribbon cable (callout 1) from the controller PCA by pressing the black tabs to release the cable. 3 Push the ribbon cable up through the hole. 4 Use the TX-20 - HP 8550mfp | Service Manual - Page 352
assembly from the 3,000-Sheet stapler/ stacker and place it on a work surface. 2 Remove the staples cartridge from the stapler. 3 Disconnect the cable from its connector and unthread the cable from the cable guides. Figure 200. Stapler removal (1 of 3) 350 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 353
the grounding screw (callout 1) and release the grounding cable. 5 Use the TX-20 screwdriver to remove two screws and their washers by the two metal tabs located on the side of the stapler opposite the screws. 6 Use firm pressure to slide the stapler toward the tab side of the stapler, clearing the - HP 8550mfp | Service Manual - Page 354
to show the tabs (callout 1) and tab slots (callout 2). 2 12 Figure 202. Stapler removal (3 of 3) To reinstall Place the tabs in the tab holes and use firm pressure to slide the stapler toward the screws side of the stapler, lining up the screw holes. Do not attempt to replace the screws - HP 8550mfp | Service Manual - Page 355
cover. 2 Release the seven cables, including the C-link cable, from their connectors (callout 1) on the stapler/stacker controller PCA. 3 Use Pull the controller PCA from the product. See chapter 7, Troubleshooting, for information about the service LEDs (callout 3). Placing the controller PCA on a - HP 8550mfp | Service Manual - Page 356
LED PCA 1 Remove the front cover. 2 Use the TX-10 screwdriver to remove one screw (callout 1) from the LED PCA. 3 Disconnect the cable (callout 2) to release the LED PCA. 12 2 Figure 204. LED PCA removal 354 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 357
Power supply 1 Remove the controller PCA cover. 2 Unplug the power cable (callout 1) from the power supply. 3 Disconnect the cable from the controller PCA (callout 2). 4 Use the TX-20 screwdriver to remove one screw (callout 3) from the bracket that holds the power supply in place. 2 12 32 Figure - HP 8550mfp | Service Manual - Page 358
Interlock switch 1 Remove the back cover. 2 Disconnect two cables (callout 1) from the interlock switch. 3 Squeeze the interlock switch on the top and bottom (callout 2), and slide the interlock through the hole ( - HP 8550mfp | Service Manual - Page 359
, and the carriage assembly. 2 Press the two tabs on the sides of the safety switch assembly cover (callout 1) to release it from the frame and lift the cover away from the assembly. 3 Disconnect two cables (callout 2) from the safety switch assembly. 4 Press the tabs on the bottom of the safety - HP 8550mfp | Service Manual - Page 360
1 Unplug the attachment assembly's C-link cable from the controller PCA and power cable from the power supply. 2 Use the TX-20 screwdriver to remove four screws (callout 1) from the attachment assembly. 3 Guide both cables through the hole and pull the assembly away from the product. 12 Figure 208 - HP 8550mfp | Service Manual - Page 361
Flipper ribbon cable 1 Remove the back cover and the controller PCA cover. 2 Disconnect the cable (callout 1) at both ends by pressing the black tabs on the connectors. 3 Open the three cable clips (callout 2; two of the three - HP 8550mfp | Service Manual - Page 362
Stationary caster 1 Remove front or back cover, depending upon the caster you want to replace. 2 Lay the stapler/stacker on its front or back side so that the caster being replaced is off the floor. 3 Use the TX-20 screwdriver to remove one screw (callout 1) from the inside of the frame. 4 Rotate - HP 8550mfp | Service Manual - Page 363
Adjustable caster 1 Remove the front cover, the back cover, and the foot cover. 2 Lay the stapler/stacker on its front or back side so that the caster being replaced is off the floor. 3 Use a flat blade screwdriver to snap the e-clip off of the adjusting knob (callout 1). 12 Figure 211. Adjustable - HP 8550mfp | Service Manual - Page 364
362 Chapter 6 - Removal and replacement EN - HP 8550mfp | Service Manual - Page 365
contents Pre-troubleshooting checklist 367 Printer message troubleshooting 368 Aids to troubleshooting 415 Configuration page 415 Continuous configuration page 418 Demonstration page 418 Event log 419 Service mode engine diagnostics 420 Disabling interlocks 425 Service mode formatter - HP 8550mfp | Service Manual - Page 366
toner 454 Hot offset 455 Fading 455 Color balance adjustment 457 Repetitive defects troubleshooting 462 Color developer roller 464 Charging roller 464 Black developer roller 464 Cleaning roller 464 Developer DSD wheels 464 Transfer roller 465 Transfer drum 465 Fuser 467 Imaging drum - HP 8550mfp | Service Manual - Page 367
479 3,000-sheet stapler/stacker troubleshooting 482 Calibrating the staple position 482 Troubleshooting tools 484 Printer messages 491 Communications troubleshooting 502 HP network interface support 502 Third-party network interface support 502 Diagrams 503 EN Chapter contents - HP 8550mfp | Service Manual - Page 368
366 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 369
. For HP Color LaserJet 8550 MFP printers, compare printed pages to copied pages to determine whether the problem is a print engine problem or a copy problem. Use the HP Color LaserJet 8550 MFP printer service manual to troubleshoot copy module and document feeder problems. l The printer driver is - HP 8550mfp | Service Manual - Page 370
Printer message troubleshooting Note This section contains explanations and recommended actions for messages that appear on the printer (A character other than "*" indicates an error has occurred.) 13.00.00 (event log CLEAR FUSER JAM LOWER LEFT DOOR in table 42 on page 390. See CLEAR FUSER JAM - HP 8550mfp | Service Manual - Page 371
Table 41. Numbered printer messages (continued) 13.00.07 (event log message) Two-sided turnaround paper late jam 13.00.08 (event log message) Two-sided See CLEAR INPUT DEVICE JAM in table 42 on page 391. See CLEAR INPUT DEVICE JAM in table 42 on page 391. EN Printer message troubleshooting 369 - HP 8550mfp | Service Manual - Page 372
of data that fits in the printer's internal memory is printed. If this error occurs frequently or if large or complex print jobs are often sent to the printer, add more memory to the printer. The optimum amount of memory data in the print buffer will be lost. 370 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 373
connector J2 on beam detect PCA, relay connector J40, and connector J211 on the controller board. 5 If the problem persists, replace the laser/ scanner unit. 6 If, after replacing the laser/scanner unit, the problem persists, replace the controller board. EN Printer message troubleshooting 371 - HP 8550mfp | Service Manual - Page 374
for a specific media size, but the printer detects a different size being fed from tray 1. For example, the printer was expecting specified in the printer driver or application = Media size specified in the printer driver or application Note: The size error in this message Troubleshooting EN - HP 8550mfp | Service Manual - Page 375
00.02 Description: Indicates that a warmup error has occurred in the fuser. Action: 1 Turn the printer off and on to reset the printer. 2 Verify the fuser is completely seated inside the printer. 3 Check for media jams in the fuser. 4 Replace the fuser kit. EN Printer message troubleshooting 373 - HP 8550mfp | Service Manual - Page 376
log message: 50.00.04 Description: Indicates that a fuser drive or power unit error has occurred in the fuser. Action: 1 Turn the printer off and on to reset the printer. 2 Verify the fuser is completely seated inside the printer. 3 Replace the fuser kit. 4 Replace the power supply. 5 Replace the - HP 8550mfp | Service Manual - Page 377
: Indicates that a laser malfunction has occurred. 52 SCANNER ERROR CYCLE POWER Description: Indicates that the scanner motor is not turning properly. Event log message: 51.00.01 Action: 1 Turn the printer off and on to reset the printer. 2 Reconnect connector J1001 on the laser driver PCA and - HP 8550mfp | Service Manual - Page 378
16 = More than one set of firmware upgrade DIMMs 17 = Not enough DRAM to run = EIO slot number: 1 = Bottom EIO slot 2 = Top EIO slot *The HP Color LaserJet 8550 printer supports font DIMMs; the HP Color LaserJet 8500 printer does not support font DIMMs. 376 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 379
. 54.2 CAROUSEL ERROR CYCLE POWER Event log message: 54.00.02 Description: Indicates that the color toner carousel is not working correctly. This could be caused by an obstruction in the carousel path, such as a loose shutter or disengaged toner cartridge. Action: 1 Turn the printer off and on - HP 8550mfp | Service Manual - Page 380
printer messages (continued) (54.2 CAROUSEL ERROR CYCLE POWER, continued) 8 Check electrical continuity between connector J642-1 (PYMC) and J642-2 (PBK) on the subrelay PCA when the door switch (SW673) is turned on. If there is no electrical continuity, replace the toner cartridge cover switch - HP 8550mfp | Service Manual - Page 381
Table 41. Numbered printer messages (continued) 54.4 WASTE TONER SENSOR ERROR CYCLE POWER Event log message: 54.00.04 Description: The waste toner sensor has failed. Printing cannot continue. Action: 1 Replace the waste toner sensor assembly. 2 Replace the imaging drum. 54.00.05 (event log - HP 8550mfp | Service Manual - Page 382
printer off and do not operate the printer in this condition or it can be seriously damaged. 1 Turn the printer on the carousel motor PCA after the printer is turned on. If the voltage the carousel motor PCA after the printer is turned on. If the voltage problem is not rectified after the printer is - HP 8550mfp | Service Manual - Page 383
problem is not rectified after the printer is turned off and on again, find the cause of activation of the overcurrent/overvoltage detection circuit in the power supply. Wait more than two minutes before turning the printer back on. 9 Replace the power supply. EN Printer message troubleshooting - HP 8550mfp | Service Manual - Page 384
error feeding media from tray 1. Event log message: 57.00.03 Action: Caution: Turn the printer off and do not operate the printer in this condition or it can be seriously damaged. 1 Turn the printer the printer is turned after the printer is turned problem is not rectified after the printer printer - HP 8550mfp | Service Manual - Page 385
.00.00 Description: Indicates that the internal RAM memory test failed. Action: 1 Turn the printer off and on to reset the printer. 2 Perform DRAM DIMM test from the formatter diagnostics in the Service Menu. 3 If the problem persists, replace the bad DIMM. EN Printer message troubleshooting 383 - HP 8550mfp | Service Manual - Page 386
POWER Event log message: 65.00.00 Description: Indicates a DRAM controller error. Action: 1 Turn the printer off and on to reset the printer. 2 Perform DRAM DIMM test from the formatter diagnostics in the Service Menu. 3 If the problem persists, replace the bad DIMM. 66.0. C-LINK COMM - HP 8550mfp | Service Manual - Page 387
2,000-sheet input unit lifting and feed motor error. Action: 1 Verify that the c-link and power cables are connected. 2 Turn the printer off and on to reset the printer. 3 Verify that there are no objects in assembly cabling. 11 Replace the pick-up assembly. EN Printer message troubleshooting 385 - HP 8550mfp | Service Manual - Page 388
AND CYCLE POWER Description: Indicates a multi-bin mailbox error. = Error code from the optional device 67. ERROR POWER CYCLE Description: Indicates an electronic controller error. = Description: 1 = Controller board error 2 = Controller board IC malfunction 3 = Internal communication - HP 8550mfp | Service Manual - Page 389
cards. Turn the printer back on. Description 01 = IO ASIC register error 02 = Video ASIC register error 03 = IDE ASIC register error 2 Run extended formatter diagnostics from the Service Mode Menu to troubleshoot the failure. 3 If the problem persists without the communications - HP 8550mfp | Service Manual - Page 390
width of the guides does not match the size of the media selected for the print job. Action: Adjust the media width guides to the edge of the page. Ensure the media size selected for the print job is the same as the size of media loaded in tray 1. 388 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 391
running the sensor monitor test from the Service Mode Menu, verify sensors that 8 and 9 on the printer control panel indicate 1 (on) when toggled. Note: This procedure will not work if the left lower cover interlock is not defeated. 4 Replace the duplexer. EN Printer message troubleshooting 389 - HP 8550mfp | Service Manual - Page 392
rotate and drop down but do not advance the paper, replace the feed and separation rollers using the maintenance kit. 6 If the rollers do not rotate or do not drop down, replace the pickup assembly. 7 If the problem persists, replace the VTU, which includes PS31. 390 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 393
, replace the feed and separation rollers using the maintenance kit. 6 If the rollers do not rotate or do not drop down, replace the pickup assembly. 7 If the problem persists, replace the VTU, which includes either PS31 or PS32 are damaged, replace the VTU. EN Printer message troubleshooting 391 - HP 8550mfp | Service Manual - Page 394
guide. Reinstall the transfer drum, and close the right upper door. Swing the lower (green) lever to the left, and close the front door. 2 Open each input tray, remove any jammed media, and close the input tray. 3 Open the left lower cover head assembly. 2 Ensure free movement of the double belt - HP 8550mfp | Service Manual - Page 395
Action: 1 Check for a jam in the delivery head assembly. 2 Ensure free movement in (PSExit2) sensor flags on the delivery head assembly. 3 Verify that test in the Service Mode Menu to verify all paper path sensors are functioning properly or to locate the jam. EN Printer message troubleshooting 393 - HP 8550mfp | Service Manual - Page 396
in the printer driver or application Load the media type and size indicated on the printer control panel. The and can be the default media type and size if an automatic paper override has occurred or if GO was pressed during a mount request. 394 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 397
JOB is pressed, the printer finishes printing the buffered pages before returning online. DATA RECIEVED PRESS GO KEY Event log message: None Description: The printer has received and processed data. The printer is waiting for a formfeed. Action: Press GO. EN Printer message troubleshooting 395 - HP 8550mfp | Service Manual - Page 398
control panel setting. See table 20 on page 88 for information about the TONER LOW setting. Action: 1 Turn the printer off and on to reset the printer. 2 Reconnect connector J209, and relay connectors J47 and J48 on the controller board. 3 Replace the drum kit. 396 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 399
and J48 on the controller board. 5 Replace the drum cartridge. 6 Replace the waste toner sensor. DUPLEX ERROR CHECK DUPLEXER Event log message: 54.00.03 Description: The printer has detected an error in the duplexer. Action: 1 Open the left lower cover, press the green tab on the right side of - HP 8550mfp | Service Manual - Page 400
Otherwise printing will be halted. Action: Replace the fuser kit and reset the fuser counter by pressing SELECT before attempting to print (or use the RESETS menu on the printer control panel). See table 20 on page 88 for information about the TONER LOW setting. 398 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 401
: The color toner carousel will not rotate unless the following conditions are met: Caution: Use the blue button to rotate the carousel to prevent damage to the printer. • The blue toner lever is locked. • The clear door is closed. • The imaging drum is installed. • The black toner cartridge is - HP 8550mfp | Service Manual - Page 402
Table 42. Unnumbered printer messages (continued) (INSTALL , continued) INSTALL FUSER LOWER LEFT DOOR Description: The printer has detected that the fuser is not installed. 6 Make sure that the black toner cartridge is installed. • Install the black toner cartridge if it is not installed. • - HP 8550mfp | Service Manual - Page 403
printer. 3 Replace the drum cartridge. 4 Replace the drum cartridge if the drum cartridge on/off switch guide is deformed. 5 Make sure that the drum cartridge is installed. • Install the drum cartridge if it is not installed. • If the drum cartridge the delivery cover/front cover switches on the - HP 8550mfp | Service Manual - Page 404
attempting to print. Note: All doors must be closed for the printer to 2 detect the transfer drum. If the right upper cover 3 interlock is defeated, this error will occur unless the density sensor is covered with paper. Take the transfer drum out and reinstall it. Make sure that the transfer - HP 8550mfp | Service Manual - Page 405
Action: 1 Open the front door of the printer, open the clear door, and swing the blue toner lock lever on the carousel to the right. 2 Remove the toner cartridge, and then reinstall it, making sure the cartridge is all the way in the printer. 3 Swing the blue toner lock lever on the carousel to the - HP 8550mfp | Service Manual - Page 406
manually fed. = Media type specified in the printer driver or application = Media size specified in the printer driver printer is compressing the print job so that all of the job will fit into the available printer printer memory. For more information about printer The printer is offline - HP 8550mfp | Service Manual - Page 407
on the printer control panel through the Configuration Menu (see page 88). Action: Clear this message by pressing any key. Note: This message will also be cleared if a print job is sent to the printer or if an error condition is detected by the printer. EN Printer message troubleshooting 405 - HP 8550mfp | Service Manual - Page 408
pressing SELECT, the value can be reset in the RESETS menu. 2 If the fuser has not been replaced, press GO. PRESS SELECT IF TRANSFER IS NEW Event log message: None Description: The printer has detected that a new transfer drum might have been installed. Note: This message will also occur if the - HP 8550mfp | Service Manual - Page 409
PRESS GO KEY TO CANCEL Event log message: None Description: This is a request to confirm initialization of the printer hard disk (see PRESS SELECT TO INITIALIZE DISK above). Initialization will perform a high-level check of the disk and register the disk with the disk manager software. Action - HP 8550mfp | Service Manual - Page 410
is printing the menu map. When the menu map is printed, the printer returns to an online and ready state. Action: No action is required. PROCESSING COPY OF Event log message: None Description: The printer is processing a proof-and-print or mopy-print job. Action: No action is required - HP 8550mfp | Service Manual - Page 411
Description: The multi-bin mailbox output bins are full. Action: Remove all media from the output bins on the multibin mailbox to continue printing. EN Printer message troubleshooting 409 - HP 8550mfp | Service Manual - Page 412
toner detection on the black toner cartridge and the contact for remaining toner detection on the printer for deformation or damage. • Replace defective parts. (Replace the black toner cartridge log message: None Description: The printer can support only one physical printer hard disk and two have - HP 8550mfp | Service Manual - Page 413
reset the transfer counter by pressing SELECT before attempting to print (or use the RESETS menu on the printer control panel). TRANSFER KIT OUT REPLACE KIT Event log message: None Description: The transfer drum, transfer belt, cleaning roller, and charcoal filter are past their specified life - HP 8550mfp | Service Manual - Page 414
printer online. If no key is ERROR CHECK CABLES CYCLE POWER Event log message: None Description: Communication with the 2,000-sheet input unit has been lost. Action: 1 Verify all cables are connected correctly. 2 Turn the printer off and on to reset the printer. 412 Chapter 7 - Troubleshooting - HP 8550mfp | Service Manual - Page 415
input tray is loaded, the printer automatically goes online. Pressing GO causes the printer to attempt to print the page on the default type and size media. If the condition persists, check the input tray type and size configuration in the control panel. EN Printer message troubleshooting 413 - HP 8550mfp | Service Manual - Page 416
Description: The installed tray is not supported by the printer. Event log message: None Action: want is shown. 3 Press GO to bring the printer online. If no key is pressed for 30 seconds after the media is fuser is warming up. Action: No action is required. 414 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 417
Aids to troubleshooting This section describes various tools service personnel can use to diagnose hardware problems. In addition to the tools described in this section, the service and support CD-ROM included with your service manual contains the user documentation. Use the additional information - HP 8550mfp | Service Manual - Page 418
percentage of the maximum rated life remaining for the transfer kit, fuser kit, and drum kit. For HP Color LaserJet 8550 printer models (except for the MFP model), estimates of the amount of toner remaining in each of the four cartridges are also shown. 4 Memory-shows the total memory installed in - HP 8550mfp | Service Manual - Page 419
1 3 6 4 2 5 7 8 Figure 212. Example of an HP Color LaserJet 8500 printer configuration page 1 3 6 4 2 5 7 9 8 10 Figure 213. Example of an HP Color LaserJet 8550 printer configuration page EN Aids to troubleshooting 417 - HP 8550mfp | Service Manual - Page 420
. The printer will print all of the pages in the buffer before stopping. Demonstration page Use this page to simulate printing a color image. If the image print quality is in question, a demonstration page should be printed to assure that the problem is not related to software, communications - HP 8550mfp | Service Manual - Page 421
the event log: media jam errors disk failures EIO errors catastrophic errors The last 50 errors are listed, with the most recent error first. Reoccurring events give indications of failing parts or problem areas within the printer. See the printer control panel message descriptions beginning - HP 8550mfp | Service Manual - Page 422
side of the key) and VALUE - simultaneously. For a menu map of the Service Mode Menu, see page 93. Paper path test The paper path test simulates a page moving through the paper path from input trays 1, 2, and 3 to the output bins. Removing some engine parts (such as the transfer drum) prevents paper - HP 8550mfp | Service Manual - Page 423
path test, press CANCEL JOB. The transfer drum can be removed with the right upper door open and the right cover interlock defeated (see figure 214 on page 425). However, media might not feed past the transfer area unless 11-by-17 inch or A3-sized media is used. EN Aids to troubleshooting 421 - HP 8550mfp | Service Manual - Page 424
motor test Visually and audibly inspect the cartridge motor (M3) and carousel motor (M1) as they rotate during this test. To view the printer components, run the test with the right upper door open and the transfer drum removed and the front cover and right upper door interlocks defeated (see - HP 8550mfp | Service Manual - Page 425
drum motor test. Sensor monitor test This test allows service personnel to activate and deactivate sensors in the printer to verify that the sensors are working properly. For safety reasons, the fuser, high-voltage supplies, and scanner of the test results. EN Aids to troubleshooting 423 - HP 8550mfp | Service Manual - Page 426
. Duplex paper sensor (PS24) Paper sensor in the duplexer in the output position (HP Color LaserJet 8550 only) Reverse sensor (PS26) Paper sensor in the duplexer at the reversing position (HP Color LaserJet 8550 only) Bit 0 of temperature/humidity sensor B Bit 1 of temperature/humidity sensor The - HP 8550mfp | Service Manual - Page 427
Disabling interlocks Figure 214. Right upper cover detection interlock Figure 215. Drum cartridge detection interlock EN Aids to troubleshooting 425 - HP 8550mfp | Service Manual - Page 428
Figure 216. Black toner cartridge detection interlock Figure 217. Toner carousel door detection interlock 426 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 429
Front cover Left lower door detection interlock Delivery cover Front cover detection interlock Left lower door detection interlock Front cover detection interlock Figure 218. Front cover/delivery cover detection interlocks EN Aids to troubleshooting 427 - HP 8550mfp | Service Manual - Page 430
Laser shutters Laser shutter interlocks Figure 219. Laser shutters 428 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 431
Figure 220. Left upper cover detection Figure 221. Right lower cover detection EN Aids to troubleshooting 429 - HP 8550mfp | Service Manual - Page 432
they are supported by the installed. DRAM DIMMs are tested using a pattern test, an address test does the following: a instructs the disk drive (if installed printer control panel display. 7 Press SELECT. Turn the printer off and on to exit the formatter diagnostics. 430 Chapter 7 - Troubleshooting - HP 8550mfp | Service Manual - Page 433
, all control panel keys are ignored. A cold reset changes all user-accessible printer variables stored in NVRAM to their factory defaults except for the following items: • page counts • fuser life count • transfer life count • multi-bin mailbox mode • display language Color adjust values revert - HP 8550mfp | Service Manual - Page 434
printer is powered off or when the fault log is cleared. Viewing the fault log The fault log menu appears as an Item selection only when one or more error if any error messages were recorded. Enter the fault log by using ITEM to view the fault log entry. Error message format Each error message has - HP 8550mfp | Service Manual - Page 435
pages Verify the green fuser lever is down. Verify the media size and type are set correctly in the printer driver and the printer control panel. Verify the media meets the specifications listed in the HP LaserJet Printer Family Paper Specification Guide. EN Paper path troubleshooting 433 - HP 8550mfp | Service Manual - Page 436
envelopes from sealing in the printer, set the envelope size in the printer driver as a custom size. However, setting envelopes as a custom size can cause poor fusing. Media jams When troubleshooting media jams, remember that jams are posted as a result of timing errors. That is, media fails to - HP 8550mfp | Service Manual - Page 437
Figure 222. Printer paper path For information about printer and paper handling accessory sensors, see chapter 5. EN Paper path troubleshooting 435 - HP 8550mfp | Service Manual - Page 438
1.2 seconds after PS1903 detects the leading edge of the media within approximately: 0.8 seconds (normal mode) 3.2 seconds (overhead transparency mode) 2.4 seconds (high-gloss mode) 436 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 439
mm or less, the media is automatically delivered. Door-open jam The sensors listed below detect the media when a cover is opened or closed: registration paper roller sensor (PS1) pick-up unit paper sensor (PS17) (PS5) fusing delivery sensor (PS1903) EN Paper path troubleshooting 437 - HP 8550mfp | Service Manual - Page 440
troubleshooting: 1 Verify the media type is set correctly in the printer control panel, and that the media type selected in the printer driver matches the media being printed on. 2 Verify that the media meets the specifications listed in the HP LaserJet Printer Family Paper Specification Guide - HP 8550mfp | Service Manual - Page 441
is limited only by the fill capability of the printer, and most good-quality paper has a very high white level. In addition, phosphor (used in color monitors) and toner have entirely different spectra characteristics and different color rendering capabilities. Blues generally match better than reds - HP 8550mfp | Service Manual - Page 442
Turn off any color-matching feature in the software that does not specifically mention ColorSync, ICM, or ICC. Calibrate the monitor. One option for monitor calibration is the Colorific software included on the color-productivity CD-ROM. If a color management system is being used, make sure the - HP 8550mfp | Service Manual - Page 443
Image defects troubleshooting Image orientation Unless otherwise specified, all references in this section to horizontal or vertical directions of print-quality problems refer to problems found on letter- and A4-sized media. These media sizes are fed into the printer long edge first. Because media - HP 8550mfp | Service Manual - Page 444
media moves through the printer (process direction) 5 Direction streaks occurs on pages 6 Direction banding occurs on pages Note PostScript print samples are located on the service and support CD (which is included with your service manual). Print these files by copying them to the parallel - HP 8550mfp | Service Manual - Page 445
é Leading edge é Figure 224. Color-plane registration See page 452 for a resolution to this print defect. EN Image defects troubleshooting 443 - HP 8550mfp | Service Manual - Page 446
é Leading edge é é Developer streak Figure 225. Developer streak See page 453 for a resolution to this print defect. 444 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 447
é Leading edge é Figure 226. Rain See page 453 for a resolution to this print defect. EN Image defects troubleshooting 445 - HP 8550mfp | Service Manual - Page 448
é Leading edge é Figure 227. Toner bubbles See page 453 for a resolution to this print defect. 446 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 449
é Leading edge é é 44 mm intervals é 44 mm intervals é Figure 228. Charge roller set See page 454 for a resolution to this print defect. EN Image defects troubleshooting 447 - HP 8550mfp | Service Manual - Page 450
é Leading edge é Figure 229. Waves See page 454 for a resolution to this print defect. 448 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 451
é Leading edge é Figure 230. Missing toner See page 454 for a resolution to this print defect. EN Image defects troubleshooting 449 - HP 8550mfp | Service Manual - Page 452
é Leading edge é Figure 231. Hot offset (glossy paper or transparency) See page 455 for a resolution to this print defect. 450 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 453
é Leading edge é Figure 232. Fading resulting from broken transfer guide See page 455 for a resolution to this print defect. EN Image defects troubleshooting 451 - HP 8550mfp | Service Manual - Page 454
offset from colors. Use the troubleshooting list below to resolve poor color-plane registration. If the problem still exists after you complete step 1, try step 2. If step 2 fails to solve the problem, try step 3, and so on. 1 Check manufacturing codes on toner cartridges if the problem appears - HP 8550mfp | Service Manual - Page 455
by color toner leaking from cartridges directly onto the transfer drum. Solve the problem of toner bubbles by checking the manufacturing codes on the toner cartridges (see "Toner cartridge manufacturing codes" on page 456) and replacing cartridges as needed. EN Image defects troubleshooting 453 - HP 8550mfp | Service Manual - Page 456
to low-coverage areas of the printed page. Waves can appear late in the life of a color toner cartridge, especially when the cartridge has seen prolonged use at very low coverage; there might still be toner in the cartridge, but it might be "worn out." Solve the print defect by replacing the - HP 8550mfp | Service Manual - Page 457
is characterized by blotches of toner on printed transparencies. Avoid the print defect by using only thicker transparencies specifically designed for HP Color LaserJet printers. Fading (See figure 232 on page 451 for an example of this print defect.) A broken transfer drum guide (see figure 260 on - HP 8550mfp | Service Manual - Page 458
code. If a portion of the code does not match the list below, replace the toner cartridge. Use toner cartridges that contain any of the following manufacturing codes: 9I 9J 9K 9L any cartridge that begins with the numbers 0 through 6 in place of the 9 456 Chapter 7 - Troubleshooting - HP 8550mfp | Service Manual - Page 459
with the printer driver and application settings to adjust the color output. For more information about application settings, see the online help. Clean the density sensor (see page 114). Complete the troubleshooting solutions earlier in this chapter for the color printing problem you are - HP 8550mfp | Service Manual - Page 460
B A C D Figure 233. Color adjust page A Smooth Half-tone Adjust section B Color ramps C Detail Half-tone Adjust section D Neutral axis 458 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 461
TEST PAGE appears on the display. c Press SELECT to print the color adjust page. d Press GO to exit the Color Adjust Menu. The color adjust page allows you to adjust the printer's two halftone screens for each of the four colors (black, cyan, magenta, and yellow), for a total of eight adjustments - HP 8550mfp | Service Manual - Page 462
printer control panel to the number shown in that circle. • Verify that the circles in the neutral axis areas of the color adjust test page are neutral gray (gray without a color might be necessary. If there is an overall tint of color in the circles, make the adjustments suggested by the following - HP 8550mfp | Service Manual - Page 463
background, the magenta ramp should be examined closely to determine if magenta should be increased. If the color settings are less accurate when you finish the color adjustment than when you started, reset all color values to 0 (zero) in the printer control panel and try the adjustment again. EN - HP 8550mfp | Service Manual - Page 464
roller (at 56 mm) developer DSD wheels (at 65 mm) transfer roller (at 66 mm) transfer drum (occurs once per 11-by-17 inch or A3-sized page, or every other letter- or A4-sized page) fuser (at 150.5 mm) imaging drum (at 195 mm) transfer belt (at 222 mm) 462 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 465
roller, 56 mm Developer DSD wheels 65 mm Transfer roller, 66 mm Transfer drum, once per 11-by-17 inch or A3-sized page or every other letteror A4-sized page Fuser, 150.5 mm Imaging drum, 195 mm Transfer belt, 222 mm Figure 234. Repetitive defect ruler EN Repetitive defects troubleshooting 463 - HP 8550mfp | Service Manual - Page 466
defect occurring every 65 mm. Cause: Dirty or damaged developer DSD wheels. These wheels are located on the outer ends of the color toner cartridge and appear as a black bushing. Actions: Replace the toner cartridge of the color producing the repetitive defect. 464 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 467
on which to work a hand wipe You can also use a dry, clean, soft, lint-free cloth, such as cheesecloth, to clean the transfer drum. To prevent scratches on the drum, do not use any paper products (such as tissue or paper towels) to clean the drum. EN Repetitive defects troubleshooting 465 - HP 8550mfp | Service Manual - Page 468
the transfer drum. 7 Swing the lower lever to the left making sure it clicks into place. 8 Close the right upper and front doors, and turn the printer on. 9 Reprint the print job. If cleaning does not eliminate the repetitive defect, replace the transfer drum. 466 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 469
roller. Actions: 1 Power the printer off, allow 30 minutes for the fuser to cool, and remove the fuser. 2 Turn the fuser gears and inspect the surface of the upper fusing roller. If the roller has surface defects, replace the fuser assembly. Imaging drum Symptoms: Print defects occurring every 195 - HP 8550mfp | Service Manual - Page 470
Transfer belt Symptoms: Print defects occurring every 222 mm. Cause: Defects on the transfer belt surface. Actions: Remove the transfer belt and inspect the entire belt surface. Use the transfer belt gears to rotate the belt through its travel. 468 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 471
printer electronics the C-link cable that connects the unit and the printer Begin troubleshooting 1 Print or display the error log. Evaluate the error log for any specific error page 470). • Service LED inside the back cover-The pattern of flashing (long and short) isolates the problem (see page - HP 8550mfp | Service Manual - Page 472
Solid amber The unit is experiencing a hardware malfunction. Isolate the problem using one of the other procedures described in this section. Flashing amber not jammed. The VTU might be open. Close the door. Off The printer might be in Power Press GO. Save mode. The unit is not receiving - HP 8550mfp | Service Manual - Page 473
12 3 Figure 236. Rear view of 2,000-sheet input unit 1 Service LEDs 2 DIP switches 3 Power supply Note Be sure to turn the power supply off and set all DIP switches switch the power supply back to diagnostic mode to enable the new diagnostic test. EN 2,000-sheet input unit troubleshooting 471 - HP 8550mfp | Service Manual - Page 474
will pick up paper from tray 4 and expel it; the bottom service LED will flash regularly every 0.5 seconds. Table 47. Patterns of LED corresponding slots) and are not bent. If neither of these is the problem, replace tray 4. 2 1 Registration sensor The media does not reach - Troubleshooting EN - HP 8550mfp | Service Manual - Page 475
unit diagnostic tests. Table 48. DIP switch settings for troubleshooting test procedures DIP switch Normal setting Motor test Standalone running movement and the lower service LED flashes in a pattern that indicates the problem. (See page 472 for an interpretation of the service LED patterns.) 4 - HP 8550mfp | Service Manual - Page 476
2,000-sheet input unit are functioning properly. 1 Remove the back cover from the 2,000-sheet input unit (see page 300). 2 Open the motor test. (See page 473 for an explanation of the settings.) 4 Use the switch that is located on the unit's power supply to switch to diagnostic Troubleshooting EN - HP 8550mfp | Service Manual - Page 477
the 2,000-sheet input unit's controller PCA for the sensor test. (See page 473 for an explanation of the settings.) EN 2,000-sheet input unit troubleshooting 475 - HP 8550mfp | Service Manual - Page 478
supply to switch to diagnostic mode. 4 Manually activate the sensor. • When you activate the sensor, the bottom service LED on the controller PCA comes on. When you release the sensor, the LED goes off. • If the LED does not come on, there is a problem with the sensor. Replace the corresponding - HP 8550mfp | Service Manual - Page 479
Note The multi-bin mailbox standalone diagnostic tool is a troubleshooting aid that verifies how the multi-bin mailbox functions alone. The tests are designed to be used without C-link commands from the EPH controller on the printer. Switching the multi-bin mailbox to test mode 1 Turn - HP 8550mfp | Service Manual - Page 480
blinking in a pattern, indicating an error code, a problem exists (table 49 on page 479 lists the error codes indicated by the blinking pattern). Paper path test Use only supported media types for the paper path test. 1 Manually feed paper through the input paper guide. • The paper passes across the - HP 8550mfp | Service Manual - Page 481
about the power-on status and about the attachment to and alignment of the accessory with the printer. The three service LEDs are near the center of the multi-bin mailbox back cover. The service LEDs blink independently of each other, indicating the status of the multi-bin mailbox. LED status - HP 8550mfp | Service Manual - Page 482
Service LEDs Message description Multi-bin mailbox unlatched from the printer The multi-bin mailbox is not properly attached to the printer. Flipper error in the transport belt system/delivery head assembly. Ensure free movement of the transport belt (both belts). Ensure that Troubleshooting EN - HP 8550mfp | Service Manual - Page 483
User LED Service LEDs Message description External memory error Multi-bin the delivery head position Check that the blind cover and system scan bar are installed properly. scanning. delivery head assembly. Check for free movement of the delivery head assembly. troubleshooting 481 - HP 8550mfp | Service Manual - Page 484
3,000-sheet stapler/stacker troubleshooting Note Calibrating the staple position Recalibrate the staple "To exit service mode" later in this chapter). 4 Turn the printer on and wait until Ready appears on the control panel display. The user LED, located at the top of the front cover, should blink - HP 8550mfp | Service Manual - Page 485
Press SELECT. 22 Press GO. If you set compensation values, the printer should return to Ready automatically and the user LED should return to the solid . Because you set calibration values, the printer should not allow access to the compensation values in service mode. If you did not set compensation - HP 8550mfp | Service Manual - Page 486
Note Troubleshooting tools Paper path test Using the information from the event log, you can verify a specific printer paper path with the paper SELECT. 6 Press - VALUE + to choose the number of copies and then press SELECT. To stop the paper path test, press CANCEL JOB on the control panel. - HP 8550mfp | Service Manual - Page 487
code. Jam codes used in the drawing and in the explanation are in hexadecimal representation. The time is the maximum time allowed between two events. The figure shows the flow of a normal sheet, from entry to the accumulator/offset module. Figure 240. Device timing The printer sends a delivery - HP 8550mfp | Service Manual - Page 488
stepper motor. With the proper relation of steps to length, the device knows when the sheet leaves the printer rollers. At that time, the device switches to high speed and begins a timeout of one second. If within the timeout, the device declares a jam 12. 486 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 489
LEDs. User LED-the single LED located at the top of the front cover provides information about the power-on status and attachment/ alignment to the printer. Service LEDs (see figure 203 on page 353, callout 3)-three LEDs (green, yellow, and red) located near the bottom of the controller PCA - HP 8550mfp | Service Manual - Page 490
printer is turned on after setting and exiting service mode. Perform steps 18 through 22 under "Calibrating the staple position" earlier in this chapter to return to normal operation. Stapler test/stacker test For the stapler test/stacker test, use the face-up bin 488 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 491
stacker bin reaches the bottom of its motion, triggering the stacker bin full sensor; the user LED should blink amber. EN 3,000-sheet stapler/stacker troubleshooting 489 - HP 8550mfp | Service Manual - Page 492
Blinking Printer in powersave mode or device not receiving power Device is on and ready Device is in service mode Device has a hardware malfunction Device is not correctly attached to printer, one or more bins are full, or device has a paper jam or a staple jam 490 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 493
shown, and so on. The messages and their priorities are: Printer status Warning messages Error messages Critical error messages External paper-handling device messages Control panel and event log -input/output device hardware malfunction EN 3,000-sheet stapler/stacker troubleshooting 491 - HP 8550mfp | Service Manual - Page 494
device type: 0 Paper handling controller 1 Input device 2 Output device 3 Finishing device 4 Other supported device (not in use) 5 Other supported device (not in use) zz is the error code. See the error message tables later in this chapter for more information. 492 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 495
an error code 09. This is an external memory error. Note Print a configuration page to properly identify the input or output device configured. Notice that the error format only identifies the C-link device number and the device type; it does not identify which input or output device is used in - HP 8550mfp | Service Manual - Page 496
HP 3,000-sheet stapler/stacker error messages Operating errors Table 52. Operating errors in the stapler/stacker Event Control panel log error User messages message LED Service ) Stapler out N/A N/A N/A The cartridge is out Refill the stapler. of guide. 494 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 497
log error User messages message LED Service LED Description Recommended action Stkr: Attach N/A to printer Stkr printer. Attach the device to the printer and verify that the user LED is green. The stapler door is Close the stapler open. door. EN 3,000-sheet stapler/stacker troubleshooting - HP 8550mfp | Service Manual - Page 498
, if necessary. If the problem persists, replace the flipper assembly. Media jammed at Clear the jam. flipper entry sensor. Power cycle the printer and the computer, if necessary. If the problem persists, replace the flipper assembly. 496 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 499
replace the flipper assembly. When powering on Clear the jam. or after clearing a jam, a jam is present in the paper path. Power cycle the printer and computer, if necessary. If the problem persists, replace the flipper assembly. EN 3,000-sheet stapler/stacker troubleshooting 497 - HP 8550mfp | Service Manual - Page 500
error User messages message LED Stkr: Detach 13.13 0A Blinking and Clear Jam or amber (continued) 13.23 0A 13.13 0B Blinking or amber 13.23 0B 13.13 11 Blinking or amber 13.23 11 13.13 12 Blinking or amber 13.23 12 Service printer and the computer, if necessary. If the problem - HP 8550mfp | Service Manual - Page 501
stapled. Power cycle the printer and the computer. Verify unit Error 04 66.13.17 or 66.23.17 Output device failure Service LED Blinking red (four blinks) Recommended Description action The accumulator Replace the assembly accumulator malfunctioned. assembly. If the problem - HP 8550mfp | Service Manual - Page 502
the computer. If the problem persists, replace the controller PCA. Blinking The controller PCA red is damaged. (six blinks) -Or- There is an EEPROM error. Power cycle the printer and the computer. If the problem persists, replace the controller PCA. 500 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 503
Stkr: or amber 66.23.37 Error 06 66.13.37 or 66.23.37 Output device failure Service Recommended LED Description action Blinking The controller PCA Power cycle the red is damaged. printer and the (six blinks) computer. -Or- If the problem persists, ROM has been corrupted - HP 8550mfp | Service Manual - Page 504
JetDirect product), the Response Center is available to help with any problems. Additional information is available from the HP JetDirect Printer Software Installation Guide (see page 514 for ordering information). Network interface cards are not directly interchangeable. Do not exchange interface - HP 8550mfp | Service Manual - Page 505
Diagrams This section contains general circuit (wiring) diagrams. Figure 242. Connectors on the controller board EN Diagrams 503 - HP 8550mfp | Service Manual - Page 506
Developer/ imaging drum bias supply High-voltage power supply Figure 243. General printer circuit diagram (1 of 4) 504 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 507
Figure 244. General printer circuit diagram (2 of 4) EN Diagrams 505 - HP 8550mfp | Service Manual - Page 508
Figure 245. General printer circuit diagram (3 of 4) 506 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 509
Figure 246. General printer circuit diagram (4 of 4) EN Diagrams 507 - HP 8550mfp | Service Manual - Page 510
508 Chapter 7 - Troubleshooting EN - HP 8550mfp | Service Manual - Page 511
511 Consumables, options, and accessories 511 Miscellaneous parts 514 Illustrations and parts lists 516 Major assembly locations 517 Printer covers and doors 519 Internal cover assembly 526 Internal components 528 Drum/cartridge drive assembly 540 Delivery drive assembly 541 Tray 3 assembly - HP 8550mfp | Service Manual - Page 512
2,000-sheet input unit components 560 Multi-bin mailbox components 564 3,000-sheet stapler/stacker components 570 Numerical parts list 574 Alphabetical parts list 587 510 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 513
in the description column to ensure that the part number selected is for the correct printer model. Ordering parts Note Note All standard part numbers are stocked and can be ordered from Support Materials Organization (SMO) or Support Materials Europe (SME). For information on contacting SMO - HP 8550mfp | Service Manual - Page 514
a multibin mailbox. Paper handling accessories C4785-69519 Exchange multi-bin mailbox C4788A 3,000-sheet stapler/stacker C4779A 3,000-sheet stacker C7837A Automatic document feeder C7839A 1,000-sheet input paper deck R98-1005000CN 500-sheet tray 2 512 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 515
Black toner cartridge C4150A Cyan toner cartridge C4151A Magenta toner cartridge C4152A Yellow toner cartridge C4153A Drum kit Imaging drum Two air filters Hand wipe C4154A Transfer kit Transfer drum Transfer belt Cleaning roller Charcoal filter Hand wipe C4155A 110-volt fuser kit Fuser - HP 8550mfp | Service Manual - Page 516
5021-8956 HP LaserJet Printer Family Paper Specification Guide 5021-0337 PCL/PJL Technical Reference Package 5091-6456 HP Peripherals Connectivity Solutions Guide 5966-5171 HP JetDirect Software Installation Guide (English) C3989-60115 HP Color LaserJet 8500, 8500N, 8500 DN Service and Support CD - HP 8550mfp | Service Manual - Page 517
, Danish, 8550 models C7096-40017 Control panel overlay, Italian, 8550 models C7096-40018 Control panel overlay, Russian, 8550 models C7096-40019 Control panel overlay, Czech, 8550 models J3113-61003 PCA, 10/100Base-T RY7-5044-000CN Screw kit (2,000-sheet input unit) EN Ordering parts 515 - HP 8550mfp | Service Manual - Page 518
8500 printers to HP Color LaserJet 8550 printers. These parts are forward and backward compatible. Formatters, however, are not interchangeable between models of printers. Part HP CLJ 8500 part # HP CLJ 8550 part # PCA, controller board RG5-3037-000CN RG5-3037-120CN Developer/imaging drum RG5 - HP 8550mfp | Service Manual - Page 519
Major assembly locations Delivery assembly Left cover feeder assembly Black cartridge cam assembly Black cartridge guide assembly Delivery drive assembly Paper pick-up assembly Transfer belt assembly Registration roller assembly Tray 1 pick-up assembly Registration frame assembly Tray 1 - HP 8550mfp | Service Manual - Page 520
Solenoid assembly Delivery frame assembly Fuser assembly Tray 2 Tray 3 Drum/cartridge drive assembly Color toner cartridge Black toner cartridge Imaging drum Figure 248. Major assembly locations (2 of 2) 518 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 521
and doors Figure 249. Printer covers and doors (1 of 4)-Filler panel for tray 2 (HP Color LaserJet 8550 base model only) Table 58. Printer covers and doors (1 of 4)-Filler panel for tray 2 Ref. Description Part number 1 Filler panel for tray 2 2 Filler panel bracket for tray 2 3 Screw - HP 8550mfp | Service Manual - Page 522
Figure 250. Printer covers and doors (2 of 4) 520 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 523
59. Printer doors and covers (2 of 4) Ref. 3 3B 3D 3E 4 4B 4C 8 9 10 11 12 Description Cover assembly, front Lever, shutter Strap, front door support Latch, roller action Cover assembly, left upper Lever, left upper door Spring, left upper door lever Cover, hinge Cover, front right Cover, left - HP 8550mfp | Service Manual - Page 524
Figure 251. Printer covers and doors (3 of 4) 522 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 525
51B Description Part number Qty. Filter, large air RB1-9807-000CN 1 Cover assembly, top RG0-0111-000CN 1 Cover assembly, top (HP CLJ 8550 MFP only) 1 Note This cover is the molded plastic ONLY; electronics are not attached. The cover allows for attachment of the copy module frame. Stop - HP 8550mfp | Service Manual - Page 526
Figure 252. Printer covers and doors (4 of 4) 524 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 527
Printer covers and doors (4 of 4) Ref. Description 7 Cover, right rear 16 Cover assembly, right lower 16C Stopper, open/close 16D Lever, right lower cover 42 Fan 3 (FM3) 46 Cover, tray 1 side gear 54 Hinge, stopper (tray 1 delivery assembly) Part number RA0-0067-000CN RG5-3096-000CN - HP 8550mfp | Service Manual - Page 528
Internal cover assembly Figure 253. Internal cover assembly 526 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 529
Table 62. Internal cover assembly parts Ref. 1 2 3 4 4A 5 6 7 10 Description Cover assembly, inner left Cover, inner 2 Cover, inner 3 Cover, inner 4 Label, "CAUTION" Waste toner tray Latch, roller action Media jam knob Cover, waste toner tray Part number RG0-0104-000CN RA0-0026-000CN RA0-0027- - HP 8550mfp | Service Manual - Page 530
Internal components Figure 254. Internal components (1 of 6) 528 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 531
assembly Cable, main Cable, sensor Cable, DC power Cable, power signal PCA, cartridge release lever Power supply assembly (110 V) Power supply assembly (220 V) Switch, toner cartridge cover (SW672) Face-up solenoid assembly Part number RG5-3080-000CN RF5-2036-000CN RB1-9401-000CN RG5-3053-000CN RG5 - HP 8550mfp | Service Manual - Page 532
40 Figure 255. Internal components (2 of 6) 530 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 533
7 8 10 22 23 29 30 40 501 Description Lever assembly, transfer drum Lever assembly, pressure Bushing Lever assembly, black cartridge Switch, black toner cartridge (SW644) Photo-interrupter, IC, TLP1240 Bushing Bushing Crossmember Ring, E Part number RG5-3046-000CN RG5-3045-000CN RS5-1119-000CN RG5 - HP 8550mfp | Service Manual - Page 534
Figure 256. Internal components (3 of 6) 532 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 535
Part number Cover, right rear lower corner RA0-0074-000CN Transfer drum contact assembly RG5-3044-000CN Spring, compression RB1-9675-000CN Rod, power switch RB1-6463-000CN Spring, leaf RB1-6909-000CN Gear, 11T RB1-9424-000CN Sensor assembly, color toner RG5-3034-000CN Cover - HP 8550mfp | Service Manual - Page 536
Figure 257. Internal components (4 of 6) 534 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 537
Tray rail assembly Cable, main motor Cable, carousel Cover, gear Transfer swing assembly Cable, delivery connector Lever, registration roller Main drive assembly Cable, delivery Motor, main (M4) Photo-interrupter, IC, TLP1241 Screw, RS, M3 x 6 Part number RG5-1851-000CN RG5-3942-000CN RG5-3923 - HP 8550mfp | Service Manual - Page 538
Figure 258. Internal components (5 of 6) 536 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 539
(5 of 6) Ref. 3 7 7D 14 15 17 18 24 37 Description Cover, cable Shield case assembly Rail, PCA Gear, 14T Gear, 14T Transfer drum Laser/scanner unit Sensor assembly, toner waste Screw, w/washer, M4 x 12 Part number RB1-9948-000CN RG5-3023-000CN RB2-0005-000CN RB1-9955-000CN RB1-9956-000CN RG5 - HP 8550mfp | Service Manual - Page 540
Figure 259. Internal components (6 of 6) 538 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 541
Static charge eliminator assembly Cleaning roller assembly Spring, torsion Bushing Spring, torsion Transfer drum cleaner holder assembly Cassette crossmember assembly Rail, tray 3 Transfer mount assembly Sensor slider assembly Part number RF5-2025-000CN RB1-9682-000CN RH7-1373-000CN RH7-1330-000CN - HP 8550mfp | Service Manual - Page 542
drive assembly 40 Figure 260. Drum/cartridge drive assembly Table 69. Drum/cartridge drive assembly parts Ref. - 23 36 40 Description Drum/cartridge drive assembly Motor, cartridge (M3) Developing rotary ITD Guide Part number RG5-3065-000CN RH7-1328-000CN RG5-3033-000CN RB2-010-000CN Qty - HP 8550mfp | Service Manual - Page 543
Delivery drive assembly Figure 261. Delivery drive assembly Table 70. Delivery drive assembly parts Ref. - Description Delivery drive assembly EN Part number Qty. RG5-3067-000CN 1 Illustrations and parts lists 541 - HP 8550mfp | Service Manual - Page 544
Tray 3 assembly Figure 262. Tray 3 assembly Table 71. Tray 3 assembly parts Ref. Description - Tray 3 26 Plate, end 542 Chapter 8 - Parts and diagrams Part number - RF5-1484-000CN Qty. 1 1 EN - HP 8550mfp | Service Manual - Page 545
Tray 2 assembly Figure 263. Tray 2 assembly Table 72. Tray 2 assembly Ref. Description - Tray 2 26 Plate, end EN Part number R98-1005-000CN RF5-1484-000CN Qty. 1 1 Illustrations and parts lists 543 - HP 8550mfp | Service Manual - Page 546
Paper pick-up assembly 41 40 Figure 264. Paper pick-up assembly (1 of 3) 544 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 547
Figure 265. Paper pick-up assembly (2 of 3) EN Illustrations and parts lists 545 - HP 8550mfp | Service Manual - Page 548
Figure 266. Paper pick-up assembly (3 of 3) 546 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 549
Table 73. Paper pick-up assembly parts Ref. - 20 21 40 41 48 49 51 52 87 103 501 Description , IC, TLP1230 Motor, pick-up (M5) PCA, paper pick-up Screw, tapping, pan head, M4 x 10 Part number RG5-3132-000CN RF5-1834-000CN RF5-1835-000CN RB1-0153-000CN RB1-6589-000CN RB1-6557-000CN RB1-6558-020CN - HP 8550mfp | Service Manual - Page 550
Ref. - 2 3 4 6 7 8 Description Registration frame assembly Spring, torsion Arm, sensor PCA, photo-interrupter, IC, TLP1240 Cover, sensor PCA, photosensor PCA, photosensor Part number RG5-3007-000CN RB1-6409-000CN RB1-6417-000CN WG8-5210-000CN RB1-9586-000CN RG5-3032-000CN RG5-3079-000CN Qty - HP 8550mfp | Service Manual - Page 551
Registration roller assembly Figure 268. Registration roller assembly Table 75. Registration roller assembly parts Ref. Description - Registration roller assembly Part number Qty. RG5-3009-000CN 1 EN Illustrations and parts lists 549 - HP 8550mfp | Service Manual - Page 552
Feeder assembly Figure 269. Feeder assembly Table 76. Feeder assembly parts Ref. Description - Feeder assembly 550 Chapter 8 - Parts and diagrams Part number Qty. RG5-3059-000CN 1 EN - HP 8550mfp | Service Manual - Page 553
Tray 1 pick-up assembly Figure 270. Tray 1 pick-up assembly Table 77. Tray 1 pick-up assembly parts Ref. - 10 40 Description Tray 1 pick-up assembly Roller, tray 1 pick-up Photo-interrupter, IC, TLP1240 EN Part number RG5-3054-000CN RB1-9526-000CN WG8-5210-000CN Qty. 1 1 1 Illustrations and - HP 8550mfp | Service Manual - Page 554
Tray 1 assembly Figure 271. Tray 1 assembly Table 78. Tray 1 assembly parts Ref. Description - Tray 1 assembly 552 Chapter 8 - Parts and diagrams Part number Qty. RG5-3134-000CN 1 EN - HP 8550mfp | Service Manual - Page 555
Delivery assembly Figure 272. Delivery assembly Table 79. Delivery assembly parts Ref. Description - Delivery assembly 11 Lever, paper sensing 12 Lever, paper height EN Part number RG0-0110-000CN RB1-6692-000CN RA0-0112-000CN Qty. 1 1 1 Illustrations and parts lists 553 - HP 8550mfp | Service Manual - Page 556
assembly Figure 273. Delivery cover assembly Table 80. Delivery cover assembly parts Ref. - 12 13 24 Description Delivery cover assembly Holder, flapper Cover, left upper Hinge, stopper (delivery) 554 Chapter 8 - Parts and diagrams Part number RG5-3108-000CN RB1-9751-000CN RB2-0057-000CN RF5 - HP 8550mfp | Service Manual - Page 557
Transfer belt assembly Figure 274. Transfer belt assembly Table 81. Transfer belt assembly parts Ref. Description - Transfer belt assembly Part number Qty. RG5-3047-000CN 1 EN Illustrations and parts lists 555 - HP 8550mfp | Service Manual - Page 558
Fuser assembly Figure 275. Fuser assembly (1 of 2) 556 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 559
Figure 276. Fuser assembly (2 of 2) EN Illustrations and parts lists 557 - HP 8550mfp | Service Manual - Page 560
Table 82. Fuser assembly parts Ref. - 8 9 25 Description Fuser assembly (120 V) Fuser assembly (220 V) Lever, holding, right Lever, holding, left Lever, release Part number RG5-3060-000CN RG5-3061-000CN RB1-9704-000CN RB1-9705-000CN RB1-9748-000CN Qty. 1 1 1 1 558 Chapter 8 - Parts and diagrams - HP 8550mfp | Service Manual - Page 561
Figure 277. PCA assemblies Table 83. PCA assembly parts Ref. Description Part number 1 PCA, cassette-size sensing RG5-1845-000CN 2 PCA, main relay RG5-3036-000CN 3 PCA, controller board RG5-3037-000CN PCA, controller board for HP CLJ 8550 MFP FG2-9470-000CN 4 PCA, carousel motor (M1 - HP 8550mfp | Service Manual - Page 562
2,000-sheet input unit components Figure 278. 2,000-sheet input unit covers and doors 560 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 563
assembly Roller, pick-up Plate paper limit back Plate paper limit middle Plate paper reference front Cover, rIght Cover, top (label included) Vertical transfer unit (VTU) Screws kit (2,000-sheet input unit) Part number RB2-2519-000CN RS5-8611-000CN RB1-6894-000CN XZ9-0442-000CN RF5-1834-000CN RF5 - HP 8550mfp | Service Manual - Page 564
Figure 279. 2,000-sheet input unit internal components 562 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 565
PCA assembly Paper size sensor PCA assembly Power supply cable Power supply fuse 250 V, 3.15 A Spring, tension Universal power supply assembly Screws kit (2,000-sheet input unit) Part number RG5-4204-000CN RG5-3919-000CN RB1-7835-000CN RB1-7677-000CN RG5-4205-000CN RG5-3908-000CN RG5-2166-000CN RG5 - HP 8550mfp | Service Manual - Page 566
Multi-bin mailbox components Figure 280. Multi-bin mailbox components (1 of 3) 564 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 567
Table 86. Multi-bin mailbox component parts (1 of 3) Ref. 20 21 22 23 24 25 26 27 28 29 30 31 Kit 1 Kit 3 Description User LED PCA (with cable) Adjustable fixed caster Attachment assembly (rod, bracket, cables) Blind cover Face-down bin Face-up bin Cover, front Exchange multi-bin mailbox assembly - HP 8550mfp | Service Manual - Page 568
Figure 281. Multi-bin mailbox components (2 of 3) 566 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 569
Table 87. Multi-bin mailbox component parts (2 of 3) Ref. 32 33 34 Kit 1 Kit 3 Description Flipper assembly (with cable "request") Head assembly (with metallic tape) Metallic tape and housing assembly Plastic parts 1A Anti-curl string 1B Spring for anti-curl string 1C Pulley, small bottom Hardware - HP 8550mfp | Service Manual - Page 570
Figure 282. Multi-bin mailbox components (3 of 3) 568 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 571
of 3) Ref. 35 36 37 38 39 40 41 Kit 1 Kit 2 Kit 3 Description Diagnostic LED PCA (with cable) Attachment clip Back cover Delivery head position motor Input paper guide (nosepiece) Power supply Transport belt motor (with fan) Plastic parts 1D Cable holder round gasket 1E Flat cable holder edge 1F - HP 8550mfp | Service Manual - Page 572
3,000-sheet stapler/stacker components 5 4 3 2 1 6 7 Figure 283. 3,000-sheet stapler/stacker components (1 of 2) 570 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 573
/stacker components (1 of 2) Ref. Description Part number 1 Front cover C4788-60505 2 Foot cover C4788-60525 3 Stapler bin (for stapler/stacker) Stacker bin (for stacker) C4788-60528 C4779-60505 4 Face-up bin C4788-60512 5 Back cover C4788-60504 6 Stapler door assembly with - HP 8550mfp | Service Manual - Page 574
9 8 20 21 10 22 19 11 18 15 17 16 12 13 14 Figure 284. 3,000-sheet stapler/stacker components (2 of 2) 572 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 575
Stacker controller PCA (for stacker) C4779-60507 19 Offset module (for stacker) C4779-60508 20 Accumulator assembly (for kit (stapler/stacker) C4788-60521 Paper stacker clip C4788-60527 Optical sensors kit C4779-60509 Qty. 1 1 1 1 1 1 1 2 2 1 1 1 1 1 1 1 1 1 1 EN Illustrations and parts - HP 8550mfp | Service Manual - Page 576
Foot cover 283 LED PCA 284 Safety switch assembly 284 HP LaserJet Printer Family Paper Specification - Guide PCL/PJL Technical Reference Package - HP Peripherals Connectivity Solutions Guide - HP JetDirect Software Installation Guide - (English) Control panel overlay, Hungarian, 8550 - HP 8550mfp | Service Manual - Page 577
282 Cover, top 280 Input paper guide (nosepiece) 282 HP Color LaserJet 8500, 8500N, 8500 DN Self- - Paced Training Kit (PAL HP Color LaserJet 8500, 8500N, 8500 DN Self- - Paced Training Kit (NTSC) Formatter assembly - Ref. - - - - - 25 38 31 39 - - - - - - EN Illustrations and parts - HP 8550mfp | Service Manual - Page 578
Guide (English) HP Color LaserJet 8500, 8500N, 8500 DN - Service and Support CD-ROM HP Color LaserJet 8500, 8500 N, 8500 DN - User's Guide (English) Black toner cartridge - Cyan toner cartridge - Magenta toner cartridge - Yellow toner cartridge - Drum kit - Imaging drum Two - HP 8550mfp | Service Manual - Page 579
C4782A) - Exchange duplexer - Face-down bin 280 Blind cover 280 Cover, front 280 Cover, back 282 Head assembly (with metallic tape) 281 kit - Diagnostic LED PCA (with cable) 282 Attachment assembly (rod, bracket, cables) 280 Transport belt motor (with fan) 282 Plastic parts - HP 8550mfp | Service Manual - Page 580
Table 91. Numerical parts list (continued) Part number Description Figure C4785-60521 C4785- Multi-bin mailbox, shipping lock kit - Flipper assembly 284 Accumulator assembly (stapler/stacker) 284 Carriage assembly (stapler/stacker) 284 Front cover 283 Stapler door assembly with label - HP 8550mfp | Service Manual - Page 581
Table 91. Numerical parts list (continued) Part number Description Figure C4788 8550 models - Control panel overlay, English, 8550 models - Control panel overlay, Traditional Chinese, 8550 - models Control panel overlay, Korean, 8550 models - Control panel overlay, Simplified Chinese, 8550 - HP 8550mfp | Service Manual - Page 582
Cover, inner 2 Cover, inner 3 Cover, left rear Cover, right rear Cover, hinge Cover, front right Stop, flip-up media Cover, right rear lower corner Cover, auxiliary Support, cover Cover, waste toner face-up Cover, power switch Flag, paper sensing Spring, torsion 580 Chapter 8 - Parts and diagrams - HP 8550mfp | Service Manual - Page 583
Table 91. Numerical parts list (continued) Part number Description RB1-6589-000CN RB1-6692- holding, right Lever, holding, left Lever, release Holder, flapper Cover, carousel stop Spring, torsion Crossmember Waste toner tray Cover, cable Filter, large air Filter, small air Mount, clutch Filter - HP 8550mfp | Service Manual - Page 584
-000CN RG0-0111-000CN RG0-0112-000CN Media jam knob Cover, cable Gear, 14T Gear, 14T Rail, PCA ITD guide Cover, left upper Filler panel for tray 2 Filler panel bracket for tray 2 Cover, back Latch, roller action Cover, fan Cover, inner 4 Rail, tray 3 Plate, end Feed and separation rollers Roller - HP 8550mfp | Service Manual - Page 585
parts list (continued) Part 000CN RG5-3054-000CN Cover assembly, left upper Cover assembly, rear PCA, color toner PCA, main relay PCA, controller board, 8500 models PCA, controller board, 8550 models Transfer drum Transfer drum contact assembly Lever assembly, pressure Lever assembly, transfer drum - HP 8550mfp | Service Manual - Page 586
Feeder assembly Fuser assembly (120 V) Fuser assembly (220 V) Drum/cartridge cartridge Cassette crossmember assembly Cover assembly, right lower Cable, main Cable, delivery Delivery cover assembly Transfer drum supply cable Cable, main 584 Chapter 8 - Parts and diagrams Figure 252 269 275 275 260 - HP 8550mfp | Service Manual - Page 587
parts list (continued) Part Sensor assembly, toner waste Laser/scanner unit Cable, main motor High-voltage power supply PCA, cartridge release lever Hinge holder and cable Outriggers Post charger HV module Cleaning roller HV module Separation discharge high-voltage converter Power supply assembly - HP 8550mfp | Service Manual - Page 588
Table 91. Numerical parts list (continued) Part number Description Figure Ref. RH7-5168-000CN RS5- CAUTION" Cassette size labels Screw kit (2,000-sheet input unit) Power supply fuse 250 V, 3.15 A Switch, black toner cartridge (SW644) Switch, toner cartridge cover (SW672) Photo-interrupter, IC, - HP 8550mfp | Service Manual - Page 589
parts list Description Part number 10/100Base-TX J3113A 110-volt fuser kit Fuser Six paper rollers Hand wipe C4155A 16-MB synchronous DIMM C7843A 220-volt fuser kit Fuser clip C4785-60512 Back cover C4788-60504 Black toner cartridge C4149A Blind cover C4785-60503 Brush, cleaning - HP 8550mfp | Service Manual - Page 590
parts list (continued) Description Part assembly RG5-3975-000CN Cleaning roller HV module RH3-0228-000CN C-link cable ( C3983-40016 Control panel overlay, Czech, 8550 models C7096-40019 Control panel overlay, 19 20 12 16 92 5 20 18 Kit 2 254 6 284 13 259 30 278 72 278 73 278 74 - HP 8550mfp | Service Manual - Page 591
Table 92. Alphabetical parts list (continued) Description Part number Control panel overlay, Danish, 8550 models C7096-40016 Control panel overlay, Dutch, 8500 models C3983-40009 Control panel overlay, Dutch, 8550 models C7096-40012 Control panel overlay, English, 8500 models C3983-40001 - HP 8550mfp | Service Manual - Page 592
92. Alphabetical parts list (continued) Description Part number Control panel overlay, Traditional Chinese, 8500 C3983-40002 models Control panel overlay, Traditional Chinese, 8550 C7096-40005 models Control panel overlay, Turkish, 8550 models C7096-40001 Controller PCA cover (with label - HP 8550mfp | Service Manual - Page 593
side gear Cover, waste toner tray Crossmember Cyan toner cartridge Delivery assembly Delivery cover assembly Delivery drive assembly Delivery head position motor Density sensor assembly Developer/imaging drum bias supply Developing rotary Diagnostic LED PCA (with cable) Drum kit Imaging drum Two air - HP 8550mfp | Service Manual - Page 594
parts list (continued) Description Part separation rollers RF5-1834-000CN Feeder assembly RG5-3059-000CN Filler panel cover C4788-60525 Formatter assembly C3983-67905 Front cover C4788-60505 Front LED PCA with holder and cable RG5-4204-000CN Fuser assembly (120 V) RG5-3060-000CN Fuser - HP 8550mfp | Service Manual - Page 595
's Guide (English) C3989-90937 HP Color LaserJet 8500, 8500N, 8500 DN Self- C3983-67902 Paced Training Kit (NTSC) HP Color LaserJet 8500, 8500N, 8500 DN Self- C3893-67903 Paced Training Kit (PAL) HP Color LaserJet 8500, 8500N, 8500 DN Service and Support CD-ROM C3989-60115 HP Color LaserJet - HP 8550mfp | Service Manual - Page 596
Table 92. Alphabetical parts list (continued) Description Part number HP JetDirect Software Installation Guide (English) 5966-5171 HP LaserJet Printer Family Paper Specification 5021-8956 Guide HP LocalTalk cable kit 92215N HP Peripherals Connectivity Solutions Guide 5091-6456 IEEE-1284 - HP 8550mfp | Service Manual - Page 597
92. Alphabetical parts list (continued) Description Part number Macintosh DIN-8 printer cable 92215S Magenta toner cartridge C4151A Main link cable adapter (extension) C4785-60531 Offset module (stacker) C4779-60508 Optical sensors kit C4779-60509 Outriggers RG5-4205-000CN Paper deck - HP 8550mfp | Service Manual - Page 598
parts list (continued) Description Part number Figure Ref. PCA, carousel motor (M1) PCA, cartridge release lever PCA, cassette-size sensing PCA, controller board, 8500 models PCA, controller board, 8550 HV module Power 4, 40 270 257 24 264 40 281 Kit 1 RG5-4201-000CN RG5-3849-000CN RF5- - HP 8550mfp | Service Manual - Page 599
parts list (continued) Description Part paper Roller, pick-up Roller, tray 1 pick-up Safety switch assembly Screw kit (2,000-sheet input unit) Screw, RS, M3 x 6 Screw, tapping x 12, quantity=4 Sensor assembly, color toner Sensor assembly, toner waste Sensor slider assembly Separation discharge high - HP 8550mfp | Service Manual - Page 600
Table 92. Alphabetical parts list (continued) Description Part number Separation discharge high-voltage converter PCA Shield Stop, flip-up media Stopper, open/close Strap, front door support Support, cover Switch, black toner cartridge (SW644) RG5-3966-000CN RG5-3023-000CN RB1-6486-000CN RB1 - HP 8550mfp | Service Manual - Page 601
Table 92. Alphabetical parts list (continued) Description Part number Switch, toner cartridge cover (SW672) Token Ring Torsion spring Transfer belt assembly Transfer drum Transfer drum cleaner holder assembly Transfer drum contact assembly Transfer kit Transfer drum Transfer belt Cleaning roller - HP 8550mfp | Service Manual - Page 602
600 Chapter 8 - Parts and diagrams EN - HP 8550mfp | Service Manual - Page 603
available 22 information from HP FIRST 64 ordering 61, 66, 511 paper handling 44 parts list 512 accumulator assembly 214 accumulator assembly (3,000-sheet stapler/stacker) 347 acoustic emission specifications 25 additive color process 138 adjusting color balance 457 colors 458 duplex registration - HP 8550mfp | Service Manual - Page 604
notes HP Driver Distribution Center 66 HP FIRST 64 ASAP (Automated Support Access Program) 64 ASIC test 95 assemblies black cartridge cam 517 black cartridge guide 517 cleaning roller HV module 291 delivery 517 delivery cover 554 delivery drive 285, 517 delivery frame 518 drum/cartridge drive - HP 8550mfp | Service Manual - Page 605
Line 67 Canadian DOC regulations 46 Cancel Job key 80 canceling job 388 proof and print jobs 84, 85 quick copy jobs 84 capacity circuit 24 input trays 31 media in multi-bin mailbox 33 media in printer 31 card stock. See media carousel color toner error 377 control process 162 position sensor 162 - HP 8550mfp | Service Manual - Page 606
92 color adjust page 458 color cartridge sensor 251 color page count 93 color toner carousel 136 color toner cartridges illustration 136 installing 101 lever sensor 158 location 118 replace frequency 119 sensor 157, 185 toner level detection 157 color toner lever sensor 185 colored media using 36 - HP 8550mfp | Service Manual - Page 607
89 copy module printer model included with 22 corona wire. See transfer charger counts total color pages printed 93 total pages duplexed 94 total pages printed 93 Courier default settings 90 covers front 228 front right 229 left lower 237 left rear 234 left upper 236 location 225 parts list - HP 8550mfp | Service Manual - Page 608
Center 66 drivers. See printer drivers drum imaging error 396 imaging life out 397 imaging not installed 401 imaging problems 467 life 124 new transfer 406 transfer damaged 389 transfer jams 394 transfer not installed 402 transfer problems 465 drum kit low and out messages 88 parts list 513 - HP 8550mfp | Service Manual - Page 609
controller board 199, 207 error log 469 errors 2,000-sheet input unit 384, 385 breaks and pauses 95 carousel 377 controller 386 cycle power 382 density sensor 378 DIMM 376 firmware 373 flipper 480 fuser 373 illegal output 379 input feed 379 internal 383 laser 375 laser scanner 371 messages 368 motor - HP 8550mfp | Service Manual - Page 610
380 thermistor 177 fault log 95 Fax Information Retrieval Support Technology (HP FIRST) Europe 65 U.S. 64 FCC regulations 46 features printer 136 feeder assembly 257, 550 feeding error 379 manual 404 process 179 speeds 179 field replaceable units (FRUs) 2,000-sheet input unit 298 ordering 63 parts - HP 8550mfp | Service Manual - Page 611
glossy print speeds 23 using 36 See also media Go key 80 graphics resolution 23 guide, input paper. See input paper guide (multi-bin mailbox) H half-toning 139 handling media 29 toner 57 hard disk accessories 22 failure 396 full 396 initializing 88, 407 location 43 new 406 parts list 512 removing - HP 8550mfp | Service Manual - Page 612
I/O (input/output) inside left panel 230 installing air filters 124 black toner cartridge 100 cables 74, 75 charcoal filter 120 consumables 98, 119 DIMMs 106 fuser kit 127 imaging drum 99 imaging drum kit 124 parts 217 printer on network 76 rollers 127 safety 222 transfer belt 120 transfer charger - HP 8550mfp | Service Manual - Page 613
80 See also individual keys kits drum parts list 513 fuser parts list 513 replace frequency 119 transfer life low 411 transfer life out 411 transfer parts list 513 L labels. See media language control panel overlay 79 not available 407 selecting display 97 laser error 375 illustration 136 EN - HP 8550mfp | Service Manual - Page 614
accessories 512 networks 76 parts list 513 port 76 lock detection for laser/scanner motor 170 logs error 469 event 83, 94, 407, 419 fault 95 low toner 410 lower fuser heater 171 fusing roller 136, 153 VTU rollers 204 M M1. See carousel motor M2. See drum motor M3. See cartridge motor M4. See main - HP 8550mfp | Service Manual - Page 615
service 93 tray 1 85, 103 modes (multi-bin mailbox) bidirectional 206 job separator 205 self-test 479 unidirectional 206 virtual stacker 205 Monarch-sized media. See media EN motors carousel 171, 172, 283 cartridge 171, 174, 280 developer 96 drum 96, 171, 173 error 383 fan 171, 177 laser/scanner - HP 8550mfp | Service Manual - Page 616
indicator 81 support 62 online help 81 operating environment requirements 27 environment specifications 24 specifications 24 operating system color characteristics 440 options ordering 511 parts list 512 ordering accessories 511 consumables 62, 511 DIMMs 511 documentation and software 62 options - HP 8550mfp | Service Manual - Page 617
unit) 560 covers and doors (printer) 525 delivery assembly 553 delivery cover assembly 554 delivery drive assembly 541 DIMMs 512 drum kit 513 drum/cartridge drive assembly 540 EIO 512 EIO hard disk 512 feeder assembly 550 fixing assembly 558 formatter board 515 fuser kits 513 internal components - HP 8550mfp | Service Manual - Page 618
toner cartridges 513 transfer assembly 555 transfer kits 513 upper cassette assembly 543 PCAs assemblies 559 carousel motor 282 developer/imaging drum bias supply 289 high-voltage power supply 291 main relay 293 power supply circuit 167 separation discharge high-voltage converter 295 subrelay 252 - HP 8550mfp | Service Manual - Page 619
log 83, 407 file directories 83 font list 83, 408 LaserJet demonstration 83 menu maps 83 PostScript errors 88 Printing Menu 89 problems. See errors; troubleshooting process colors 139 processing jobs 408 product data sheets 64 programs, color selection in 440 proof and print jobs, canceling 84, 85 - HP 8550mfp | Service Manual - Page 620
key 80 selecting binding 86 color 440 display language 97 media 29 self-test mode 479 sensors carousel position 162, 185 cleaning density 389 color cartridge 157, 251 color toner cartridge 185 color toner level 157 color toner lever 158, 185 defective or stuck 434 density 160, 266 density error - HP 8550mfp | Service Manual - Page 621
input trays 31 overriding media 87 printer 25 sliders problem 480 SLx. See solenoids SME (Support Materials Europe), ordering from 61 SMO (Service Materials Organization), ordering from 61 smooth color value 92 software matrix 64 ordering 62 support from HP FIRST 64 solenoids assembly 518 carousel - HP 8550mfp | Service Manual - Page 622
64 HP Direct 66 HP FIRST 64 HP JetDirect 502 HP Software Distribution Center 66 technical 64 third-party 502 websites 62 Support Materials Europe (SME) ordering information 61 620 Index switches black toner cartridge 187 carousel button 187 defective 433 delivery cover/front cover 187 imaging drum - HP 8550mfp | Service Manual - Page 623
print defect 453 Toner Cartridge MSDS 57 EN toner cartridges cover switch 187 installing black 100 installing color 101 location 118 manufacturing codes 456 recycling 70 refilling 69 replace frequency 119 warranty 69 toner gauge 110 toner lock sensor 251 tools required for service 223 top (face - HP 8550mfp | Service Manual - Page 624
printers 37 parts list 513 print speeds 23 process 179 reducing curl 433 sensors 179, 183, 185 using 392 media specifications 31 toner catch 116 See also tray 1; tray 2; tray 3; tray 4 troubleshooting 2,000- errors TrueType fonts 23 typeface support 64 types, configuring media 103, 104 622 Index - HP 8550mfp | Service Manual - Page 625
media 411 unlatched multi-bin mailbox 480 unlocked toner lever 403 unrecoverable error 387 upper fuser heater 171 fusing roller 136, 153 VTU rollers 204 user guide parts list 514 user interface features 23 user-replaceable parts 224 V Value key 80 VCCI statement (Japan) 54 ventilation requirements - HP 8550mfp | Service Manual - Page 626
624 Index EN - HP 8550mfp | Service Manual - Page 627
- HP 8550mfp | Service Manual - Page 628
Printed on Recycled Paper Copyright© 2000 Hewlett-Packard Co. Printed in the USA Manual Part No. C7096-90967 *C7096-90967* *C7096-90967* C7096-90967
-
1 -
2 -
3 -
4 -
5 -
6 -
7 -
8
-
9
-
10
-
11
-
12
-
13
-
14
-
15
-
16
-
17
-
18
-
19
-
20
-
21
-
22
-
23
-
24
-
25
-
26
-
27
-
28
-
29
-
30
-
31
-
32
-
33
-
34
-
35
-
36
-
37
-
38
-
39
-
40
-
41
-
42
-
43
-
44
-
45
-
46
-
47
-
48
-
49
-
50
-
51
-
52
-
53
-
54
-
55
-
56
-
57
-
58
-
59
-
60
-
61
-
62
-
63
-
64
-
65
-
66
-
67
-
68
-
69
-
70
-
71
-
72
-
73
-
74
-
75
-
76
-
77
-
78
-
79
-
80
-
81
-
82
-
83
-
84
-
85
-
86
-
87
-
88
-
89
-
90
-
91
-
92
-
93
-
94
-
95
-
96
-
97
-
98
-
99
-
100
-
101
-
102
-
103
-
104
-
105
-
106
-
107
-
108
-
109
-
110
-
111
-
112
-
113
-
114
-
115
-
116
-
117
-
118
-
119
-
120
-
121
-
122
-
123
-
124
-
125
-
126
-
127
-
128
-
129
-
130
-
131
-
132
-
133
-
134
-
135
-
136
-
137
-
138
-
139
-
140
-
141
-
142
-
143
-
144
-
145
-
146
-
147
-
148
-
149
-
150
-
151
-
152
-
153
-
154
-
155
-
156
-
157
-
158
-
159
-
160
-
161
-
162
-
163
-
164
-
165
-
166
-
167
-
168
-
169
-
170
-
171
-
172
-
173
-
174
-
175
-
176
-
177
-
178
-
179
-
180
-
181
-
182
-
183
-
184
-
185
-
186
-
187
-
188
-
189
-
190
-
191
-
192
-
193
-
194
-
195
-
196
-
197
-
198
-
199
-
200
-
201
-
202
-
203
-
204
-
205
-
206
-
207
-
208
-
209
-
210
-
211
-
212
-
213
-
214
-
215
-
216
-
217
-
218
-
219
-
220
-
221
-
222
-
223
-
224
-
225
-
226
-
227
-
228
-
229
-
230
-
231
-
232
-
233
-
234
-
235
-
236
-
237
-
238
-
239
-
240
-
241
-
242
-
243
-
244
-
245
-
246
-
247
-
248
-
249
-
250
-
251
-
252
-
253
-
254
-
255
-
256
-
257
-
258
-
259
-
260
-
261
-
262
-
263
-
264
-
265
-
266
-
267
-
268
-
269
-
270
-
271
-
272
-
273
-
274
-
275
-
276
-
277
-
278
-
279
-
280
-
281
-
282
-
283
-
284
-
285
-
286
-
287
-
288
-
289
-
290
-
291
-
292
-
293
-
294
-
295
-
296
-
297
-
298
-
299
-
300
-
301
-
302
-
303
-
304
-
305
-
306
-
307
-
308
-
309
-
310
-
311
-
312
-
313
-
314
-
315
-
316
-
317
-
318
-
319
-
320
-
321
-
322
-
323
-
324
-
325
-
326
-
327
-
328
-
329
-
330
-
331
-
332
-
333
-
334
-
335
-
336
-
337
-
338
-
339
-
340
-
341
-
342
-
343
-
344
-
345
-
346
-
347
-
348
-
349
-
350
-
351
-
352
-
353
-
354
-
355
-
356
-
357
-
358
-
359
-
360
-
361
-
362
-
363
-
364
-
365
-
366
-
367
-
368
-
369
-
370
-
371
-
372
-
373
-
374
-
375
-
376
-
377
-
378
-
379
-
380
-
381
-
382
-
383
-
384
-
385
-
386
-
387
-
388
-
389
-
390
-
391
-
392
-
393
-
394
-
395
-
396
-
397
-
398
-
399
-
400
-
401
-
402
-
403
-
404
-
405
-
406
-
407
-
408
-
409
-
410
-
411
-
412
-
413
-
414
-
415
-
416
-
417
-
418
-
419
-
420
-
421
-
422
-
423
-
424
-
425
-
426
-
427
-
428
-
429
-
430
-
431
-
432
-
433
-
434
-
435
-
436
-
437
-
438
-
439
-
440
-
441
-
442
-
443
-
444
-
445
-
446
-
447
-
448
-
449
-
450
-
451
-
452
-
453
-
454
-
455
-
456
-
457
-
458
-
459
-
460
-
461
-
462
-
463
-
464
-
465
-
466
-
467
-
468
-
469
-
470
-
471
-
472
-
473
-
474
-
475
-
476
-
477
-
478
-
479
-
480
-
481
-
482
-
483
-
484
-
485
-
486
-
487
-
488
-
489
-
490
-
491
-
492
-
493
-
494
-
495
-
496
-
497
-
498
-
499
-
500
-
501
-
502
-
503
-
504
-
505
-
506
-
507
-
508
-
509
-
510
-
511
-
512
-
513
-
514
-
515
-
516
-
517
-
518
-
519
-
520
-
521
-
522
-
523
-
524
-
525
-
526
-
527
-
528
-
529
-
530
-
531
-
532
-
533
-
534
-
535
-
536
-
537
-
538
-
539
-
540
-
541
-
542
-
543
-
544
-
545
-
546
-
547
-
548
-
549
-
550
-
551
-
552
-
553
-
554
-
555
-
556
-
557
-
558
-
559
-
560
-
561
-
562
-
563
-
564
-
565
-
566
-
567
-
568
-
569
-
570
-
571
-
572
-
573
-
574
-
575
-
576
-
577
-
578
-
579
-
580
-
581
-
582
-
583
-
584
-
585
-
586
-
587
-
588
-
589
-
590
-
591
-
592
-
593
-
594
-
595
-
596
-
597
-
598
-
599
-
600
-
601
-
602
-
603
-
604
-
605
-
606
-
607
-
608
-
609
-
610
-
611
-
612
-
613
-
614
-
615
-
616
-
617
-
618
-
619
-
620
-
621
-
622
-
623
-
624
-
625
-
626
-
627
-
628
 |
 |
Service Manual
English
8500/8550 Printer Family