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Loop control,

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Loop control The loop control monitors the tension of the paper between the second-transfer roller and the fuser. ● If the fuser rollers rotate more slowly than the secondary transfer rollers, the paper warp increases and an image defect or paper crease occurs. ● If the fuser rollers rotate faster than the secondary transfer rollers, the paper warp decreases and the toner image fails to transfer to the paper correctly, causing color misregistration. To prevent these problems, the loop sensors, which are located between the secondary transfer rollers and the fuser rollers, detect whether the paper is sagging or is too taut. The DC controller adjusts the speed of the fuser motor. Figure 1-42 Loop-control mechanism ENWW Pickup, feed, and delivery system 53

Section	Page
Theory of operation	37
Basic operation	38
Sequence of operation	39
Engine control system	40
DC controller	41
Solenoids	42
Clutches	42
Switches	42
Sensors	43
Motors and fans	43
High voltage power supply	46
Low voltage power supply	48
Overcurrent/overvoltage protection	50
Safety	50
Sleep (powersave) mode	50
Power supply voltage detection	50
Low voltage power supply failure	50
Power off condition	51
Fuser control	51
Fuser temperature control circuit	52
Fuser over temperature protection	53
Fuser failure detection	54
Laser/scanner system	55
Image formation system	57
Image formation process	58
Step 1: Pre-exposure	59
Step 2: Primary charging	59
Step 3: Laser-beam exposure	60
Step 4: Development	60
Step 5: Primary transfer	61
Step 6: Secondary transfer	61
Step 7: Separation	62
Step 8: Fusing	62
Step 9: ITB cleaning	63
Step 10: Drum cleaning	63
Print cartridge	63
Developing roller engagement and disengagement	65
Intermediate transfer belt (ITB) unit	67
Primary-transfer-roller engagement and disengagement	68
ITB cleaning	71
Calibration	72
Color misregistration control	72
Image stabilization control	73
Pickup, feed, and delivery system	74
Pickup-and-feed unit	78
Cassette pickup	79
Cassette presence detection	80
Cassette lift operation	81
Cassette paper presence detection	82
Cassette media width detection	83
Multifeed prevention	84
Multipurpose tray pickup	85
Paper feed	86
Skew-feed prevention	87
OHT detection	88
Fusing and delivery unit	88
Loop control	89
Pressure-roller pressurization control	90
Duplexing unit (duplex models)	91
Duplexing reverse and feed control	92
Duplex pickup operation	92
Jam detection	93
Optional paper feeder	95
Paper-feeder pickup and feed operation	97
Paper size detection and cassette presence detection	98
Paper feeder cassette lift operation	100
Paper feeder presence detection	102
Paper-feeder multiple feed prevention	103
Paper feeder jam detection	104
Removal and replacement	105
Introduction	106
Removal and replacement strategy	106
Cautions during removal and replacement	106
Electrostatic discharge	107
Required tools	108
Service approach	109
Before performing service	109
After performing service	109
Post service test	109
Print-quality test	109
Parts removal order	110
Customer self repair (CSR) components	112
Print cartridges	112
Duplex reverse guide	114
Toner collection unit	115
Formatter PCA	117
Disk drives	118
Remove the HDD	118
Remove the SSM	120
Install a replacement hard drive	121
Reload the firmware	121
Tray cassette	122
Fuser	123
Pickup roller (Tray 1)	124
Pickup roller (Tray 2)	125
Pickup and feed rollers (Tray 3)	127
Separation roller (Tray 2)	129
Secondary transfer roller	130
Reinstall the transfer roller	131
Secondary transfer assembly	132
Reinstall the secondary transfer assembly	133
Intermediate transfer belt (ITB)	134
Right door (optional paper feeder)	136
Covers	138
Identification and location	138
Front door assembly	139
Right door assembly	141
Right rear cover	145
Left cover	147
Remove the left cover	147
Left bottom cover	149
Remove the left bottom cover	149
Left bottom handle	150
Remove the left bottom handle	150
Hardware integration pocket (HIP) (dn and xh models only)	151
Control panel assembly	152
Right front cover	154
Remove the right front cover	154
Reinstall the power button	157
Front top cover	158
Remove the front top cover	158
Rear cover and upper rear cover	160
Remove the rear cover and upper rear cover	160
Rear top cover	163
Remove the rear top cover	163
Right bottom handle	165
Remove the right bottom handle	165
Rear bottom handle	166
Remove the rear bottom handle	166
Internal assemblies	167
Delivery fan, cartridge fan, and environmental sensor	167
Remove the delivery fan, cartridge fan, and environmental sensor	167
Toner collection sensor	172
Remove the toner collection sensor	172
Residual toner feed motor	174
Remove the residual toner feed motor	174
Reinstall the residual toner collection door	178
Registration density (RD) sensor assembly	179
Remove the RD sensor assembly	179
Power supply fan and fan duct	183
Remove the power supply fan and fan duct	183
Registration assembly	186
Remove the registration assembly	186
Lower pickup guide	191
Remove the lower pickup guide	191
Reinstall the lower pickup guide	193
Interconnect board (ICB)	194
Remove the ICB	194
DC controller PCA and tray	196
Remove the DC controller PCA	196
Low voltage power supply	199
Remove the low voltage power supply	199
High voltage power supply lower (HVPS-D)	203
Remove the high voltage power supply lower	203
Reinstall the high voltage power supply lower	205
Developing disengagement motor	206
Remove the developing disengagement motor	206
Pickup motor	208
Remove the pickup motor	208
Lifter drive assembly	209
Remove the lifter drive assembly	209
Automatic close assembly	211
Remove the automatic close assembly	211
Cassette pickup drive assembly	212
Remove the cassette pickup drive assembly	212
Reinstall the cassette pickup drive assembly	217
Cassette pickup assembly	219
Remove the cassette pickup assembly	220
Laser/scanner assembly (Y/M)	222
Remove the laser/scanner assembly (Y/M)	222
Laser/scanner assembly (C/Bk)	229
Remove the laser/scanner assembly (C/Bk)	230
Reinstall the protective glass cleaner (PGC) actuators	234
High voltage power supply upper (HVPS-T)	237
Remove the high voltage power supply upper	238
Reinstall the high voltage power supply upper	241
Drum motor 1	242
Remove the drum motor 1	243
Drum motor 2 or drum motor 3	244
Remove the drum motor 2 or drum motor 3	245
Fuser motor	246
Remove the fuser motor	247
Main drive assembly	248
Remove the main drive assembly	249
Reinstall the main drive assembly	253
Fuser drive assembly	259
Remove the fuser drive assembly	260
Reinstall the fuser drive assembly	263
Delivery assembly	264
Remove the delivery assembly	265
Reinstall the delivery assembly	268
Duplex drive assembly	269
Remove the duplex drive assembly	270
Optional paper feeder assembly (Tray 3)	271
Drawer connector	271
Solve problems	273
Solve problems checklist	274
Menu map	276
Current settings pages	277
Preboot menu options	278
Troubleshooting process	279
Determine the problem source	279
Troubleshooting flowchart	279
Power subsystem	280
Power-on checks	280
Power-on troubleshooting overview	280
Tools for troubleshooting	282
Individual component diagnostics	282
LED diagnostics	282
Understand lights on the formatter	282
Heartbeat LED	282
Heartbeat LED, product initialization	283
Connectivity LED, product operating	285
Connectivity LED	286
Connectivity LED, product initialization	286
Connectivity LED, product operating	288
HP Jetdirect LEDs	289
Engine diagnostics	290
Defeating interlocks	290
Disable cartridge check	292
Engine test button	293
Paper path test	294
Paper path sensors test	294
Manual sensor test	296
Registration sensor	297
Fuser loop sensors	298
Fuser output sensor	299
Duplexer refeed sensor	300
Output-bin full sensor	301
Fuser pressure-release sensor	302
ITB alienation sensor	303
Right- and front-door interlock switches	305
Tray/bin manual sensor test	307
Tray 1 paper sensor	308
Tray 2 paper sensor	309
Tray 2 cassette sensor	310
Tray 2 cassette lifter sensor	311
Tray 3 empty sensor	312
Tray 3 media feed sensor	313
Tray 3 stack surface sensor	314
Tray 3 media size sensors	315
Print/stop test	315
Component tests	316
Component test (special-mode test)	316
Diagrams	318
Block diagrams	318
Location of connectors	320
DC controller PCA	320
Paper feeder driver PCA	321
Plug/jack locations	322
Locations of major components	322
Base product	322
1 x 500 paper feeder	329
General timing chart	330
Circuit diagrams	331
Internal print-quality test pages	333
Print quality troubleshooting pages	333
Print quality assessment page	336
Cleaning page	338
Set up an auto cleaning page	338
Configuration page	339
Configuration page	339
HP embedded Jetdirect page	341
Finding important information on the configuration pages	342
Color band test	343
Print quality troubleshooting tools	344
Repetitive defects ruler	344
Calibrate the product	345
Control panel menus	346
Sign In menu	346
Retrieve Job From USB menu	347
Retrieve Job From Device Memory menu	348
Supplies menu	352
Trays menu	360
Administration menu	365
Reports menu	365
General Settings menu	367
Retrieve From USB Settings menu	385
General Print Settings menu	385
Default Print Options menu	388
Display Settings menu	391
Manage Supplies menu	392
Manage Trays menu	399
Network Settings menu	401
Troubleshooting menu	418
Device Maintenance menu	424
Backup/Restore menu	424
Calibrate/Cleaning menu	424
USB Firmware Upgrade menu	427
Interpret control panel messages, status-alert messages, and event code errors	428
10.0X.Y0 Supply memory error	428
10.22.50	429
10.22.51	429
10.22.52	429
10.23.50	429
10.23.51	430
10.23.52	430
10.23.60	430
10.23.70 Printing past very low	430
10.XX.34 Used supply in use	431
10.XX.40 Genuine HP supplies installed	431
10.XX.41 Unsupported supply in use	432
10.XX.70 Printing past very low	432
10.YY.15 Install <supply>	433
10.YY.25 Wrong cartridge in <color> slot	433
10.YY.35 Incompatible <supply>	434
11.00.YY Internal clock error	435
13.00.00	435
13.A3.D3	435
13.A3.FF	435
13.B2.9C	435
13.B2.A1	436
13.B2.A2	436
13.B2.A3	436
13.B2.D1	436
13.B2.D2	436
13.B2.D3	436
13.D3.DZ	437
13.WX.EE	437
13.WX.FF	437
13.WX.YZ Fuser area jam	438
13.WX.YZ Fuser wrap jam	439
13.WX.YZ Jam below control panel	440
13.WX.YZ Jam in middle right door	440
13.WX.YZ Jam in right door	441
13.WX.YZ Jam in Tray 1	441
13.WX.YZ Jam in Tray <X>	442
20.00.00 Insufficient memory To continue, press OK	442
21.00.00 Page too complex	442
32.08.XX	443
32.1C.XX	443
32.21.00	447
33.XX.YY	448
33.XX.YY Used board/disk	448
41.02.00 Error	448
41.03.YZ Unexpected size in tray <X>	449
41.05.YZ Unexpected type in tray <X>	449
41.07.YZ Error To continue, press OK	451
42.XX.YY	453
47.00.XX	453
47.01.XX	453
47.02.XX	453
47.03.XX	454
47.04.XX	454
47.05.00	454
47.06.XX	454
47.WX.YZ Printer calibration error To continue, press OK	454
49.XX.YY To continue, turn off then on	456
50.WX.YZ Fuser error To continue, turn off then on	457
51.00.YY Error	460
52.00.XX To continue, turn off then on	460
54.XX.YY Error	461
55.00.YY DC controller error To continue, turn off then on	463
55.0X.YY DC controller error To continue, turn off then on	463
56.00.YY Error To continue, turn off then on	463
57.00.0Y Error To continue, turn off then on	464
58.00.04	464
59.00.YY Error To continue, turn off then on	465
59.05.XX	465
60.00.0Y Tray <Y> lifting error	466
61.00.01	467
62.00.00 No system To continue, turn off then on	467
70.00.00 Error To continue, turn off then on	467
81.0X.YY Embedded JetDirect error	468
98.00.01 Corrupt data in firmware volume	468
98.00.02 Corrupt data in solutions volume	469
98.00.03 Corrupt data in configuration volume	469
98.00.04 Corrupt data in job data volume	469
99.00.01 Upgrade not performed file is corrupt	469
99.00.02 Upgrade not performed timeout during receive	470
99.00.03 Upgrade not performed error writing to disk	470
99.00.04 Upgrade not performed timeout during receive	470
99.00.05 Upgrade not performed timeout during receive	470
99.00.06 Upgrade not performed error reading upgrade	471
99.00.07 Upgrade not performed error reading upgrade	471
99.00.08 Upgrade not performed error reading upgrade	471
99.00.09 Upgrade canceled by user	471
99.00.10 Upgrade canceled by user	472
99.00.11 Upgrade canceled by user	472
99.00.12 Upgrade not performed the file is invalid	472
99.00.13 Upgrade not performed the file is invalid	472
99.00.14 Upgrade not performed the file is invalid	473
99.00.2X	473
99.09.60 Unsupported disk	474
99.09.61 Unsupported disk	474
99.09.62 Unknown disk	474
99.09.63 Incorrect disk	474
99.09.64 Disk malfunction	474
99.09.65 Disk data error	475
99.09.66 No disk data installed	475
99.09.67 Disk is not bootable please download firmware	475
99.XX.YY	475
99.XX.YY	476
<Binname> Full Remove all paper from bin	476
<Supply> almost full	476
<Supply> low OR Supplies low	476
<Supply> very low OR Supplies very low	477
<Tray X> lifting	478
[File System] device failure To clear, press OK	478
[File System] file operation failed To clear, press OK	478
[File System] file system is full To clear, press OK	478
[File System] is not initialized	479
[File System] is write protected	479
Accept bad signature	479
Bad optional tray connection	479
Calibration reset pending	480
Canceling	480
Canceling... <jobname>	480
Checking engine	480
Checking paper path	480
Chosen personality not available To continue, press OK	481
Cleaning do not grab paper	481
Cleaning...	481
Clearing event log	481
Clearing paper path	481
Close front door	482
Close lower right door	482
Close upper right door	482
Creating cleaning page	482
Data received To print last page, press OK	483
EIO <X> disk initializing	483
Event log is empty	483
Expected drive missing	483
HP Secure Hard Drive disabled	483
Incompatible <supply>	484
Incompatible supplies	484
Install <supply>	485
Install <supply> Close rear door	485
Install Fuser Unit	485
Install supplies	486
Install Transfer Unit	486
Internal disk not functional	486
Internal disk spinning up	487
Load Tray <X>: [Type], [Size]	487
Load Tray <X>: [Type], [Size] To use another tray, press OK	487
Manually feed output stack Then press OK to print second sides	488
Manually feed: [Type], [Size]	488
Manually feed: [Type], [Size] To use another tray, press OK	488
Moving solenoid	488
Moving solenoid and motor	489
No job to cancel	489
Paused	489
Performing Color Band Test...	489
Performing Paper Path Test...	489
Please wait...	490
Printing CMYK samples...	490
Printing Color Usage Log...	490
Printing Configuration...	490
Printing Demo Page...	490
Printing Diagnostics Page...	490
Printing Engine Test...	491
Printing Event Log...	491
Printing File Directory...	491
Printing Font List...	491
Printing Fuser Test Page...	491
Printing Help Page...	492
Printing Menu Map...	492
Printing PQ Troubleshooting...	492
Printing Registration Page...	492
Printing RGB Samples...	492
Printing stopped	492
Printing Supplies Status Page...	493
Printing Usage Page...	493
Processing duplex job Do not grab paper until job completes	493
Processing job from tray <X>... Do not grab paper until job completes	493
Processing...	493
Processing... copy <X> of <Y>	494
Ready	494
Ready <IP Address>	494
Remove all print cartridges	494
Remove at least one print cartridge	494
Remove shipping lock from Tray 2	495
Replace <supply>	495
Replace Supplies	496
Restore Factory Settings	497
Restricted from printing in color	497
Rotating <color> motor	497
Rotating motor	497
Size mismatch in Tray <X>	498
Sleep mode on	498
Supplies in wrong positions	498
Tray <X> empty: [Type], [Size]	499
Tray <X> open	499
Tray <X> overfilled	500
Troubleshooting	500
Type mismatch Tray <X>	500
Unsupported drive installed To continue, press OK	500
Unsupported supply in use OR Unsupported supply installed To continue, press OK	501
Unsupported tray configuration	501
Unsupported USB accessory detected Remove USB accessory	501
USB accessory needs too much power Remove USB and turn off then on	502
USB accessory not functional	502
Used supply installed To continue, press OK OR Used supply in use	502
Wrong cartridge in <color> slot	503
Event log messages	504
Print an event log	505
View an event log	506
Clear an event log	506
Clear jams	507
Common causes of jams	507

Match case Limit results 1 per page

Loop control

The loop control monitors the tension of the paper between the second-transfer roller and the fuser.

●

If the fuser rollers rotate more slowly than the secondary transfer rollers, the paper warp increases

and an image defect or paper crease occurs.

●

If the fuser rollers rotate faster than the secondary transfer rollers, the paper warp decreases and

the toner image fails to transfer to the paper correctly, causing color misregistration.

To prevent these problems, the loop sensors, which are located between the secondary transfer rollers

and the fuser rollers, detect whether the paper is sagging or is too taut. The DC controller adjusts the

speed of the fuser motor.

Figure 1-42

Loop-control mechanism

ENWW

Pickup, feed, and delivery system