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HP 4600 Service Manual - Page 174

Image density detection, the formatter.

UPC - 808736060875

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Image density detection Each of the image stabilization controls uses the color registration unit at the top of the ETB unit to measure image density. The DC controller emits a light from sensors located above the density detection patterns on the ETB. The light reflected off the patterns is returned to the sensor, and the data is returned to the DC controller. Figure 5-32 Image density detection illustrates this process. When the values that the density sensor detects are outside the specified range, the DC controller resets the image density and issues an "image density sensor out of guaranteed range" warning to the formatter. If the sensor receives no reflected light, the DC controller stops the printer and issues a "density sensor abnormality" warning to the formatter. Figure 5-32 Image density detection 158 Chapter 5 Theory of operation ENWW

Section	Page
Product information	17
Model configurations	18
HP Color LaserJet 4600 Series printer	18
Printer features	21
Printer features	21
Printer assemblies	25
HP Color LaserJet 4600 models	25
HP Color LaserJet 4610n printer	26
HP Color LaserJet 4650 models	27
Identification, site requirements, and specifications	29
Model and serial numbers	29
Power and regulatory label	30
Site requirements	30
Space requirements	32
Physical specifications	33
Electrical specifications	33
Environmental specifications	34
Acoustic emissions	34
Supply storage requirements	35
Print media	36
Print-media specifications	36
Media to avoid	38
Media that can cause damage to the printer	38
Printing on special media	39
Transparencies	39
Glossy paper	40
Colored paper	40
Printing images	40
Envelopes	40
Labels	41
Heavy paper	41
HP LaserJet Tough paper	42
Preprinted forms and letterhead	42
Recycled paper	43
Weight equivalence table	44
Environmental product stewardship program	45
Protecting the environment	45
Ozone production	45
Power consumption	45
Paper use	45
Plastics	45
HP LaserJet printing supplies	45
HP Printing Supplies Returns and Recycling Program Information	45
Recycled paper	46
Material restrictions	46
For more information	46
Hewlett-Packard limited warranty statement	47
Declaration of conformity	48
Country/region laser safety statements	50
Canadian DOC regulations	50
EMI statement (Korea)	50
VCCI statement (Japan)	50
Laser Statement for Finland	51
Japan power-cord statement	51
Service approach	53
Service approach	54
Parts and supplies	55
Ordering parts, supplies, and accessories over the Internet	55
Ordering directly through the embedded Web server (for printers with network connections)	55
Ordering directly through the HP Toolbox software (HP CLJ 4650 only)	55
Exchange program	56
Supplies	56
World Wide Web	56
HP Service Parts Information	56
HP customer care	57
Online services	57
Telephone support	57
Software utilities, drivers, and electronic information	57
HP service information	57
HP service agreements	57
HP support and information for Macintosh computers	58
Ordering related documentation and software	58
Installation and configuration	59
Unpacking the printer	60
Installing the media tray	65
Connecting power	66
Installing the print cartridges	66
Installing a new overlay (HP Color LaserJet 4600 models)	69
Installing a new control-panel label (HP Color LaserJet 4650 models)	70
Testing the printer operation	71
Using PowerSave	72
To set PowerSave Time	72
To turn PowerSave on or off	72
Connecting to a computer	73
Parallel connections	73
USB configuration (HP Color LaserJet 4610n and 4650 models)	74
Auxiliary connection configuration (HP Color LaserJet 4650 models)	74
Network connections	75
Direct to network (HP Color LaserJet 4600 and 4650 models)	75
Network print server (HP Color LaserJet 4600 and 4650 models)	75
Network print server (HP Color LaserJet 4610n printer)	77
Peer-to-peer (direct to network, HP Color LaserJet 4600 and 4650 models)	78
Peer-to-peer (parallel)	78
Enhanced I/O (EIO) configuration	78
HP Jetdirect print servers	79
Available enhanced I/O interfaces	79
NetWare networks	79
Windows and Windows NT networks	80
AppleTalk networks	80
LocalTalk configuration	80
LocalTalk network configuration	80
UNIX and Linux networks	80
Wireless printing	80
IEEE 802.11b standard	80
Bluetooth	81
Printer drivers	82
Available drivers	83
Additional drivers	84
Select the right printer driver for your needs	84
Printer driver Help	84
Software for Macintosh computers	85
PPDs	85
HP LaserJet Utility	85
Installing the printing system software	86
Installing Windows printing system software for direct connections	86
Installing Windows printing system software for networks	87
To set up Windows-sharing to use the printer on a network	88
Installing Macintosh printing system software for networks	88
Installing Macintosh printing system software for direct connections (USB, HP Color LaserJet 4610n a ...	90
Installing the software after the parallel or USB cable has been connected	91
Network configuration	93
Configuring the printer for the network	93
Configuring Novell NetWare frame type parameters	93
Software for networks	94
HP Web Jetadmin	94
UNIX	95
Utilities	95
Embedded Web server (HP Color LaserJet 4600 and 4650 models only)	96
Features	96
HP Toolbox (HP Color LaserJet 4650 models only)	96
Other components and utilities	97
Setting network security on the printer	98
Locking the control panel	98
Levels of security	98
Using an ASCII PJL escape sequence to set network security	99
Maintenance	101
Cleaning the printer and accessories	102
Cleaning spilled toner	102
Vacuum specifications	102
Approximate replacement intervals for supply items	103
ETB life under different circumstances	105
Locating supplies	107
Replacing supply items	108
Changing print cartridges	108
Replacing the transfer unit	110
Replacing the transfer unit when it is not at end of life	112
Replacing the fuser	113
Replacing the fuser when it is not at end of life	115
Printer memory (HP Color LaserJet 4600 models)	116
Installing memory and font DIMMs (HP Color LaserJet 4600 models)	116
Enabling memory (HP Color LaserJet 4600 models)	118
Enabling the language font DIMM (HP Color LaserJet 4600 models)	119
Checking DIMM installation (HP Color LaserJet 4600 models)	119
Printer memory (HP Color LaserJet 4610n and 4650 models)	120
Installing memory (HP Color LaserJet 4610n and 4650 models) and fonts (HP Color LaserJet 4650 models)	121
To install DDR memory DIMMs (HP Color LaserJet 4610n and 4650 models)	121
To install a flash memory card (HP Color LaserJet 4610n and 4650 models)	125
Enabling memory (HP Color LaserJet 4610n and 4650 models)	129
To enable memory for Windows 98, ME, and NT (HP Color LaserJet 4650 models)	129
To enable memory for Windows 2000 and XP (HP Color LaserJet 4610n and 4650 models)	129
Installing an HP Jetdirect print server card (HP Color LaserJet 4600 and 4650 models only)	130
Installing an HP Jetdirect print server card (HP Color LaserJet 4610n model)	132
Theory of operation	133
Basic operation	134
Operation sequence	135
Engine-control system	136
DC controller circuit	137
Motors, fans, and environment sensor	138
Fuser power-supply circuit	140
Heater temperature control	142
High-voltage power supply	143
Low-voltage power supply	144
Formatter system	145
PowerSave	146
Input/output	147
Parallel interface	147
Expanded I/O (HP Color LaserJet 4600 models)	147
USB 1.1 connector (HP Color LaserJet 4610n and 4650 models)	147
Flash (HP Color LaserJet 4600 models)	147
Hard-disk accessory (HP Color LaserJet 4600 and 4650 models)	147
CPU	147
Printer memory	148
Read-only memory	148
Random-access memory	148
DIMM slots (HP Color LaserJet 4600 Series printer)	148
Firmware DIMM (HP Color LaserJet 4600 models)	148
Flash memory (HP Color LaserJet 4610n and 4650 models)	148
Nonvolatile memory	148
PJL overview	149
PML	149
Control panel	149
Laser/scanner assembly	150
Scanner-motor control	151
Image-formation system	152
Image-formation process	153
Print cartridges	154
Memory tag	155
Toner-level detection	155
Developer rotations	156
Toner sensor	156
Photosensitive drum rotations	156
Developing cylinder disengaging control	157
Electrostatic transfer/transport belt (ETB) unit	158
Electrostatic-latent-image-formation block	159
Step 1: Primary exposure	159
Step 2: Primary charging	160
Step 3: Laser beam exposure	160
Development block	161
Step 4: Toner charging	161
Step 5: Development	161
Transfer block	162
Step 6: Attaching	162
Step 7: Transfer	162
Step 8: Separation	164
Fusing block	164
Step 9: Fusing	164
Cleaning block	165
Step 10: ETB cleaning	165
Step 11: Photosensitive drum cleaning	165
Calibration and cleaning	166
ETB cleaning	168
Photosensitive drum cleaning	169
Color-plane registration calibration	170
Drum phase calibration	171
Image stabilization control	171
Environmental change control (HP Color LaserJet 4610n and 4650 models)	172
Image density calibration control (DMAX)	172
Image halftone calibration control (DHALF)	173
Image density detection	174
Pickup/feed system	175
Pickup/feed unit	177
Cassette detection and cassette paper-size detection	178
Overhead transparency detection	179
Small-size paper detection	180
Feed-speed control	181
Fuser/delivery unit	182
Duplex feed unit	183
500-sheet paper feeder	184
Pickup and feed operations	185
2 x 500-sheet feeder	186
Pickup and feed system	187
Cassette detection and cassette paper-size detection	188
Removal and replacement	189
Introduction	190
Repair notices	190
Caution regarding electrostatic discharge (ESD)	190
Required tools	190
Types of fasteners	191
Supplies	192
Print cartridges and ETB	193
Covers and external components	194
Rear cover	194
Top cover	195
Rear top cover	197
Left cover	199
Right cover	200
Multipurpose tray (tray 1)	201
Front cover	202
Control panel	203
Installing a new overlay (HP Color LaserJet 4600 models)	205
Installing a new control-panel label (HP Color LaserJet 4650 models)	206
Internal components	207
DC controller shield	207
Internal components (front)	208
Paper pickup unit	208
Paper pickup sensor PCA	210
Cassette (tray 2) paper pickup rollers	211
Paper pickup drive unit	212
Multipurpose tray pickup roller and separation pad	213
Solenoids	215
Color registration detection unit	216
Internal components (left side)	218
Environment sensor (HP Color LaserJet 4610n/4650 models only)	218
Drum drive units	219
Memory-tag antenna PCAs	225
Developing disengaging motor assembly	226
DC controller PCA	227
Memory controller PCA	228
Cassette paper-size-detection switch	229
Internal components (rear)	230
Formatter	230
Low-voltage power supply	231
Power-supply fan (HP Color LaserJet 4610n and 4650 models)	233
Formatter case	234
Laser/scanner components	236
Remove the laser/scanner cover plate	236
Remove the laser/scanner retaining bars	238
To remove the laser/scanner assemblies	240
Internal components (right side)	241
High-voltage power supply PCA	241
Toner level detection PCA	243
High-voltage contact blocks	244
Door switch	245
Internal components (top)	246
Fuser power supply PCA	246
Fuser drive unit	248
Fuser inlet paper sensor	250
Fuser delivery sensor	251
Output-bin-full sensor	252
Cartridge fan	253
Formatter fan	254
Optional 500-sheet paper feeder (HP Color LaserJet 4600 and 4650 models only)	255
500-sheet paper feeder top cover plate	255
500-sheet paper feeder drive unit	256
500-sheet paper-feeder pickup rollers	258
500-sheet paper-feeder PCA	258
Optional 2 x 500-sheet paper feeder (tray 3/tray 4) (HP Color LaserJet 4650 only)	259
2 x 500-sheet paper feeder front cover	259
2 x 500-sheet paper feeder rear cover	260
2 x 500-sheet paper feeder left cover	261
2 x 500-sheet paper feeder right cover	262
2 x 500-sheet paper feeder upper-cassette pickup assembly	263
2 x 500-sheet paper-feeder drive assembly	264
2 x 500-sheet paper-feeder feed sensor	265
2 x 500-sheet paper feeder upper- or lower-cassette paper sensor	266
2 x 500-sheet paper feeder upper- or lower-cassette paper-detection switch	268
2 x 500-sheet paper-feeder driver PCA	269
2 x 500-sheet paper feeder pickup rollers	270
Troubleshooting	271
Introduction	272
Troubleshooting process	274
Pre-troubleshooting checklist	275
Troubleshooting basics	277
Troubleshooting power-on	278
Printer-error troubleshooting	279
Status messages	279
Warning messages	279
Error messages	279
Critical error messages	279
Alphabetical printer messages (HP Color LaserJet 4600 models)	280
Alphabetical printer messages (HP Color LaserJet 4610n and 4650 models)	295
Numerical printer messages (HP Color LaserJet 4600 models)	314
Numerical printer messages (HP Color LaserJet 4610n and 4650 models)	327
Replacement-parts configuration (HP Color LaserJet 4610n and 4650 models)	345
Formatter and DC controller	345
Formatter (new or previously installed in another printer)	345
DC Controller (new or previously installed in another printer)	346
Paper-path troubleshooting	347
Jams	347
Jam locations	347
Jam locations by error message	348
Jam recovery	349
To disable paper jam recovery	350
Avoiding jams	350
Persistent jams	351
Basic troubleshooting for jams	351
Data collection	351
General paper-path troubleshooting	352
Paper-path checklist	352
Jams in tray 1	353
Jams in tray 2	353
Jams in tray 3 or tray 3/tray 4 (2 x 500-sheet paper feeder, HP CLJ 4650 only)	354
Jams in the paper path	355
Jams in the top cover	356
Jams in the duplex path (HP CLJ 4600 and 4650 models only)	356
Media-transport troubleshooting	357
Multiple pages are fed	357
Media is wrinkled or folded	357
Paper is skewed	358
Image-formation troubleshooting	359
Online print-quality troubleshooting tools (HP Color LaserJet 4610n and 4650 models)	359
Print-quality problems associated with media	359
Overhead transparency defects	360
Print-quality problems that are associated with the environment	360
Print-quality problems that are associated with jams	361
Print-quality troubleshooting pages	361
Understanding color variations	361
Common causes of color variation	361
Color selection process	362
Matching colors	362
PANTONE®* color matching	362
Swatch book color matching	362
Using color	363
HP ImageREt 2400 (HP Color LaserJet 4600 models)	363
HP ImageREt 3600 (HP Color LaserJet 4610n and 4650 models)	363
Paper selection	363
sRGB	363
Color options	364
Print in Grayscale	364
Automatic or manual color adjustment	364
Manual color options	364
Halftone options	365
Neutral Grays	365
Edge Control	365
RGB Color	365
Adjusting color balance	366
To adjust color density	366
Image defects troubleshooting	367
Light image	368
Light color	368
Dark image	369
Dark color	369
Completely blank image	369
All black or solid color	369
Dots in vertical lines	370
Dirt on the back of the paper	370
Dirt on the front of the paper	371
Vertical lines	371
White vertical lines	371
Horizontal lines	372
White horizontal lines	372
Missing color	372
Blank spots	373
Poor fusing	373
Distortion or blurring	374
Smearing	374
Misplaced image	374
Repetitive defects troubleshooting	375
Interface troubleshooting	379
Communications checks	379
EIO troubleshooting (HP CLJ 4600 and 4650 models only)	379
AUTOEXEC.BAT standard configurations	380
Parallel MS-DOS commands	380
Printer Job Language (PJL) commands	380
@PJL [Enter]	380
UEL	380
@PJL COMMENT	380
@PJL INFO CONFIG	381
@PJL INFO ID	381
@PJL INFO USTATUS	381
@PJL INFO PAGECOUNT	381
@PJL JOB	381
@PJL EOJ	381
@PJL ECHO	381
@PJL USTATUS JOB=ON/OFF	381
@PJL USTATUSOFF	382
Control-panel troubleshooting	383
Printing a menu map	383
Information menu	385
Paper handling menu	386
Configure device menu	387
Printing menu	387
Print quality menu	390
System setup menu	392
I/O menu	396
Resets menu	397
Diagnostics menu	398
Service menu	399
Tools for troubleshooting	401
Embedded Web server (HP Color LaserJet 4600 and 4650 models only)	401
To open the embedded Web server	401
Information tab	402
Settings tab	402
Networking tab	403
Other links	403
Printer Status and Alerts software	403
To specify which status messages appear	404
To view status messages and information	404
Printer information pages	404
Menu map	404
Configuration page	405
Supplies status page	408
Usage page	410
Demo page	411
File directory page	412
PCL font list page	412
PS font list page	414
RGB samples page (HP Color LaserJet 4610n and 4650 models)	414
CMYK samples page (HP Color LaserJet 4610n and 4650 only)	415
Diagnostics	416
LED diagnostics	416
Engine diagnostics	417
Diagnostics mode	417
Diagnostics that put the engine into the special diagnostics mode	417
Diagnostic tests	418
Individual diagnostic tests	419
Print the event log page	419
View the event log on the control-panel display	419
Print the PQ troubleshooting pages	419
Disable cartridge check (special mode test)	420
Paper path sensor test (HP Color LaserJet 4610n and 4650 models)	420
Paper-path test	421
Sensor Test (special mode test)	421
Manual sensor test (special mode test; HP Color LaserJet 4610n and 4650 models)	424
Component test (special mode test)	429
Print/Stop test	434
Information menu	434
Configure device menu/printing menu	435
Configure device menu/resets menu	435
Configure device menu/print quality menu	435
Test pages	436
Engine test page	436
Formatter test page	436
Engine resets	437
Cold reset	437
To perform a cold reset	437
NVRAM initialization	437
To initialize NVRAM	438
Resetting the calibration values for the DC controller	438
To reset the calibration values for the DC controller	438
Hard disk initialization	438
To initialize the hard disk	438
Calibration bypass	438
To bypass calibration	439
Calibrate Now (HP Color LaserJet 4600 models)	439
Quick Calibrate Now (HP Color LaserJet 4610n and 4650 models)	439
Full Calibrate Now (HP Color LaserJet 4610n and 4650 models)	440
Service menu	441
Using the Service menu	441
Clear event log	441

Match case Limit results 1 per page

Image density detection

Each of the image stabilization controls uses the color registration unit at the top of the ETB unit to

measure image density. The DC controller emits a light from sensors located above the density

detection patterns on the ETB. The light reflected off the patterns is returned to the sensor, and the

data is returned to the DC controller.

Figure

5-32

Image

density

detection

illustrates this process.

When the values that the density sensor detects are outside the specified range, the DC controller

resets the image density and issues an “image density sensor out of guaranteed range” warning to

the formatter.

If the sensor receives no reflected light, the DC controller stops the printer and issues a “density

sensor abnormality” warning to the formatter.

Figure 5-32

Image density detection

158

Chapter 5

Theory of operation

ENWW