HP Color Laserjet M575 troubleshooting manual

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LASERJET ENTERPRISE 500 COLOR MFP LASERJET ENTERPRISE COLOR FLOW MFP M575

Troubleshooting Manual

M575

M575c

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HP LaserJet Enterprise 500 color MFP M575 Printers HP LaserJet Enterprise 500 color flow MFP M575 Printers

Troubleshooting Manual

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Reproduction, adaptation, or translation without prior written permission is prohibited, except as allowed under the copyright laws.

The information contained herein is subject to change without notice.

The only warranties for HP products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional warranty. HP shall not be liable for technical or editorial errors or omissions contained herein.

Part number: CD644-90967

Edition 2, 11/2012

Trademark Credits

, Adobe Photoshop®, Acrobat®, and

Adobe PostScript

are trademarks of Adobe

Systems Incorporated.

Apple and the Apple logo are trademarks of Apple Computer, Inc., registered in the U.S. and other countries. iPod is a trademark of Apple Computer, Inc. iPod is for legal or rightholder-authorized copying only. Don't steal music.

Microsoft®, Windows®, Windows® XP, and Windows Vista® are U.S. registered trademarks of Microsoft Corporation.

PANTONE® is Pantone, Inc's checkstandard trademark for color.

is a registered trademark of The

UNIX Open Group.

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Conventions used in this guide

TIP: Tips provide helpful hints or shortcuts.

NOTE: Notes provide important information to explain a concept or to complete a task.

CAUTION: Cautions indicate procedures that you should follow to avoid losing data or damaging

the product.

WARNING! Warnings alert you to specific procedures that you should follow to avoid personal

injury, catastrophic loss of data, or extensive damage to the product.

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iv Conventions used in this guide ENWW

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Table of contents

1 Theory of operation .......................................................................................................... 1

Basic operation ........................................................................................................................ 2

Sequence of operation ............................................................................................... 3

Engine-control system ................................................................................................................ 4

DC controller ............................................................................................................ 5

Solenoids .................................................................................................. 5

Clutches .................................................................................................... 6

Switches ................................................................................................... 6

Sensors ..................................................................................................... 7

Motors and fans ......................................................................................... 8

High-voltage power supply ......................................................................................... 9

Low-voltage power supply ........................................................................................ 11

Overcurrent/overvoltage protection ............................................................ 12

Safety ..................................................................................................... 13

Voltage detection ..................................................................................... 13

Sleep (powersave) mode ........................................................................... 13

Power supply voltage detection .................................................................. 14

Low-voltage power supply failure ............................................................... 14

Power Off condition ................................................................................................ 14

Auto on/Auto off mode ............................................................................................ 14

Fuser (fixing) control ................................................................................................ 16

Fuser (fixing) temperature-control circuit ...................................................... 17

Fuser (fixing) over-temperature protection .................................................... 17

Fuser (fixing)-failure detection .................................................................... 18

Laser/scanner system ............................................................................................................. 20

Image formation system .......................................................................................................... 22

Image formation process .......................................................................................... 23

Step 1: Pre-exposure ................................................................................. 24

Step 2: Primary charging .......................................................................... 24

Step 3: Laser-beam exposure ..................................................................... 25

Step 4: Development ................................................................................ 25

Step 5: Primary transfer ............................................................................ 26

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Step 6: Secondary transfer ........................................................................ 26

Step 7: Separation ................................................................................... 27

Step 8: Fusing ......................................................................................... 27

Step 9: ITB cleaning ................................................................................. 28

Step 10: Drum cleaning ............................................................................ 28

Toner cartridge ....................................................................................................... 28

Developing roller engagement and disengagement ..................................................... 30

Intermediate transfer belt (ITB) unit ............................................................................. 32

Primary-transfer-roller engagement and disengagement ................................. 33

ITB cleaning ............................................................................................ 35

Calibration ............................................................................................................. 36

Color misregistration control ...................................................................... 36

Image stabilization control ........................................................................ 37

Pickup, feed, and delivery system ............................................................................................. 38

Pickup-and-feed unit ................................................................................................ 41

Tray pickup ............................................................................................. 42

Tray-presence detection .............................................................. 43

Tray lift operation ...................................................................... 43

paper-presence detection ........................................................... 45

Multifeed prevention .................................................................. 45

Multipurpose tray pickup ........................................................................... 46

Paper feed .............................................................................................. 47

Skew-feed prevention ................................................................. 48

OHT detection .......................................................................... 48

Fusing and delivery unit ........................................................................................... 49

Loop control ............................................................................................ 49

Pressure-roller pressurization control ........................................................... 51

Duplexing unit ........................................................................................................ 52

Duplexing reverse and feed control ............................................................ 53

Duplex pickup operation ........................................................................... 53

Jam detection ........................................................................................................................ 54

Optional paper feeder ............................................................................................................ 56

Paper-feeder pickup and feed operation .................................................................... 58

Paper size detection and presence detection .............................................................. 59

Paper feeder lift operation ........................................................................................ 61

Paper feeder presence detection ............................................................................... 62

Paper-feeder multiple feed prevention ........................................................................ 62

Paper feeder jam detection ....................................................................................... 64

Scanning/image capture system .............................................................................................. 65

Control panel ......................................................................................................... 65

Scanner ................................................................................................................. 65

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Document feed system ............................................................................................. 65

Document feeder operation (M575dn and 575f models) ............................... 66

Sensors in the document feeder (M575dn and 575f models) .......... 66

Document feeder paper path (M575dn and 575f models) .............. 67

Document feeder simplex operation (M575dn and 575f models) .... 68

Document feeder duplex operation (M575dn and 575f models) ..... 69

Document feeder operation (M575c model) ................................................ 72

Sensors in the document feeder (M575c model) ............................ 72

Document feeder paper path (M575c model) ............................... 74

Document feeder simplex operation (M575c model) ...................... 75

Document feeder e-duplex operation (M575c model) ..................... 76

Frontside and backside background selector (M575c model) .......... 76

Document feeder operation (all models) ...................................................... 77

Deskew operation ..................................................................... 77

Document feeder hinges ............................................................. 78

Stapler .................................................................................................................................. 80

2 Solve problems ............................................................................................................... 81

Solve problems checklist ......................................................................................................... 82

Menu map ............................................................................................................................ 84

Preboot menu options ............................................................................................................. 85

Current settings pages ............................................................................................................ 92

Troubleshooting process .......................................................................................................... 93

Determine the problem source ................................................................................... 93

Troubleshooting flowchart ......................................................................... 93

Power subsystem ..................................................................................................... 94

Power-on checks ...................................................................................... 94

Power-on troubleshooting overview .............................................. 94

Control-panel checks ............................................................................................... 95

Scanning subsystem ................................................................................................ 97

Tools for troubleshooting ......................................................................................................... 98

Individual component diagnostics .............................................................................. 98

LED diagnostics ........................................................................................ 98

Understand lights on the formatter ............................................... 98

Engine diagnostics ................................................................................. 102

Defeating interlocks ................................................................. 102

Disable cartridge check ........................................................... 104

Engine test button .................................................................... 105

Paper path test ....................................................................................... 106

Paper path sensors test ........................................................................... 106

Manual sensor test ................................................................................. 108

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SW1 Front Door ..................................................................... 109

SR8 Registration sensor ............................................................ 111

SR14 Fuser Loop 1 and SR15 Fuser Loop 2 sensors ..................... 112

SR7 Fuser Pressure Release sensor ............................................. 113

SR5 Fuser Output sensor .......................................................... 115

SR22 Duplexer Refeed sensor ................................................... 117

SR6 Output Bin Full sensor ........................................................ 118

SR11 Developer Alienation sensor ............................................. 119

SR17 ITB Alienation sensor ....................................................... 120

Tray/bin manual sensor test ..................................................... 122

Print/stop test ........................................................................................ 130

Component tests ..................................................................................... 131

Component test (special-mode test) ............................................ 131

Diagrams ............................................................................................................. 133

Block diagrams ...................................................................................... 133

Location of connectors ............................................................................ 134

DC controller PCA ................................................................... 134

Paper feeder driver PCA .......................................................... 135

Plug/jack locations ................................................................................. 136

Locations of major components ................................................................ 136

Base product .......................................................................... 137

1 x 500 paper feeder .............................................................. 143

General timing chart ............................................................................... 144

Circuit diagrams .................................................................................... 145

Internal print-quality test pages ................................................................................ 149

Print quality troubleshooting pages ........................................................... 149

Print quality assessment page .................................................................. 152

Cleaning page ....................................................................................... 154

Set up an auto cleaning page ................................................... 154

Print configuration page .......................................................................... 155

Configuration page ................................................................. 155

HP embedded Jetdirect page .................................................... 157

Finding important information on the configuration pages ............ 158

Color band test ...................................................................................... 159

Print quality troubleshooting tools ............................................................................ 159

Repetitive defects ruler ............................................................................ 159

Calibrate the product to align the colors .................................................... 160

Control panel menus .............................................................................................. 161

Administration menu ............................................................................... 161

Reports menu .......................................................................... 161

General Settings menu ............................................................. 162

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Copy Settings menu ................................................................. 178

Scan/Digital Send Settings menu .............................................. 187

Fax Settings menu ................................................................... 198

General Print Settings menu ...................................................... 212

Default Print Options menu ....................................................... 214

Display Settings menu .............................................................. 216

Manage Supplies menu ........................................................... 218

Manage Trays menu ................................................................ 224

Network Settings menu ............................................................ 226

Troubleshooting menu .............................................................. 240

Device Maintenance menu ...................................................................... 244

Backup/Restore menu .............................................................. 244

Calibration/Cleaning menu ...................................................... 245

USB Firmware Upgrade menu ................................................... 248

Service menu .......................................................................... 248

Interpret control-panel messages ............................................................................. 249

Control-panel message types ................................................................... 249

Control-panel messages .......................................................................... 249

10.0X.Y0 Supply memory error ................................................ 249

10.XX.34 Used supply in use .................................................... 250

10.XX.40 Genuine HP supplies installed .................................... 250

10.XX.41 Unsupported supply in use ......................................... 251

10.XX.70 Printing past very low ................................................ 251

10.YY.15 Install <supply> ........................................................ 252

10.YY.25 Wrong cartridge in <color> slot ................................. 253

10.YY.35 Incompatible <supply> .............................................. 253

11.00.YY Internal clock error To continue, touch “OK” ................ 254

13.A3.A3 Jam in lower right door ............................................ 254

13.AD.D3 Jam in tray .............................................................. 255

13.B2.AD Jams in right door .................................................... 255

13.B2.Az Jam in right door ...................................................... 256

13.B2.D1 Jam in tray 1 ........................................................... 256

13.B2.D2 Jam in tray 2 ........................................................... 257

13.B2.D3 Jam in lower right door ............................................. 257

13.B2.DD Jam in right door ...................................................... 258

13.B9.Az Jam in right door ...................................................... 259

13.B9.Cz Fuser Wrap Jam ....................................................... 259

13.B9.Cz Fuser wrap jam ........................................................ 260

13.B9.DD Jam in right door ...................................................... 260

13.B9.Dz Jam in right door ...................................................... 261

13.BA.EE Jam in right door ...................................................... 262

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13.FF.FF Jam in right door ........................................................ 262

13.WX.YZ Jam in Tray <X> ...................................................... 263

20.00.00 Insufficient memory: <Device> To continue, touch “OK” 263

21.00.00 Page too complex To continue, touch “OK” ................. 264

30.01.23 Scanner calibration failure ........................................ 264

30.01.36 Upgrade Error Try downloading upgrade again .......... 264

30.01.43 Scan memory failure To continue turn off then on ......... 264

30.01.YY Scanner failure To continue turn off then on ................. 265

30.WX.YZ Scanner fan failure To continue turn off then on .......... 265

31.01.03 Document feeder pick error ....................................... 266

31.01.47 Document feeder not detected .................................... 266

31.03.22 Scanner calibration failure ........................................ 266

31.WX.10 Scanner failure To continue turn off then on ................ 266

31.WX.15 Jam in document feeder ........................................... 267

32.1C.XX ............................................................................... 267

32.21.00 ............................................................................... 271

33.02.01 ............................................................................... 272

33.WX.YZ Used board/disk installed ........................................ 272

40.00.01 USB I/O buffer overflow To continue, touch “OK” ........ 272

40.00.02 Embedded I/O buffer overflow To continue, touch “OK” 272

41.03.YZ Unexpected size in Tray <X> ..................................... 272

41.03.YZ Unexpected size in Tray <X> To use another tray, touch

"Options" ............................................................................... 273

41.05.YZ Unexpected type in Tray <X> ..................................... 273

41.05.YZ Unexpected type in Tray <X> To use another tray,

touch "Options" ...................................................................... 275

41.WX.YZ Error To use another tray, touch "Options" ................. 276

42.XX.YY ............................................................................... 277

47.FC.YZ Printer calibration failed To continue, touch “OK” ......... 277

48.01.XX Error ....................................................................... 278

49.XX.YY Error To continue turn off then on ................................ 278

50.WX.YZ Fuser error To continue turn off then on ...................... 279

51.00.YY Error To continue turn off then on ................................ 282

52.00.00 Error To continue turn off then on ............................... 283

52.00.20 Error To continue turn off then on ............................... 284

54.XX.YY Error ....................................................................... 284

55.XX.YY DC controller error To continue turn off then on ............ 285

55.XX.YY DC controller error To continue turn off then on ............ 286

56.00.01 Illegal Input Printer Error To continue turn off then on .... 286

56.00.YY Error To continue turn off then on ................................ 287

57.00.0X Error ....................................................................... 287

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58.00.04 Error To continue turn off then on ............................... 288

59.00.30 Error To continue turn off then on ............................... 288

59.00.40 Error To continue turn off then on ............................... 288

59.00.B0 Cleaning motor error Replace Toner Collection Unit ...... 289

59.00.YY Error To continue turn off then on ................................ 289

59.05.XX ............................................................................... 294

59.0X.50 Error To continue turn off then on ................................ 296

59.0X.60 Error To continue turn off then on ................................ 296

60.00.0Y Tray <Y> lifting error ................................................ 297

61.00.01 ............................................................................... 297

62.00.00 No system To continue turn off then on ........................ 297

70.00.00 Error To continue turn off then on ............................... 297

80.0X.YY Embedded JetDirect Error .......................................... 298

81.WX.00 Wireless Network Error To continue turn off then on ... . 300

81.WX.YZ Embedded JetDirect Error To continue turn off then on . . 300

89.19.5C Error ....................................................................... 301

99.00.01 Upgrade not performed file is corrupt ......................... 301

99.00.02 Upgrade not performed timeout during receive ............ 301

99.00.03 Upgrade not performed error writing to disk ................ 301

99.00.04 Upgrade not performed timeout during receive ............ 302

99.00.05 Upgrade not performed timeout during receive ............ 302

99.00.06 Upgrade not performed error reading upgrade ............ 302

99.00.07 Upgrade not performed error reading upgrade ............ 302

99.00.08 Upgrade not performed error reading upgrade ............ 303

99.00.09 Upgrade canceled by user ........................................ 303

99.00.10 Upgrade canceled by user ........................................ 303

99.00.11 Upgrade canceled by user ........................................ 303

99.00.12 Upgrade not performed the file is invalid .................... 304

99.00.14 Upgrade not performed the file is invalid .................... 304

99.00.2X ............................................................................... 304

99.09.60 Unsupported Disk ..................................................... 305

99.09.61 Unsupported disk ..................................................... 305

99.09.62 Unknown disk .......................................................... 305

99.09.63 Incorrect disk ........................................................... 305

99.09.64 Disk malfunction ....................................................... 305

99.09.65 Disk data error ......................................................... 306

99.09.66 No disk data installed ............................................... 306

99.09.67 Disk is not bootable please download firmware ........... 306

99.XX.YY ............................................................................... 306

<Binname> full Remove all paper from bin ................................. 307

<Supply> almost full ................................................................ 307

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<Supply> low ......................................................................... 307

<Supply> low OR Supplies low ................................................. 307

<Supply> very low .................................................................. 308

<Supply> very low To continue, touch “OK” ............................... 309

<Supply> very low OR Supplies very low ................................... 309

[File System] device failure To clear press OK ............................. 310

[File System] file operation failed To clear press OK .................... 310

[File System] file system is full To clear press OK ......................... 310

[File System] is not initialized .................................................... 310

[File System] is write protected .................................................. 310

A second USB wireless networking accessory has been detected . . 311

Accept bad signature ............................................................... 311

Bad optional tray connection .................................................... 311

Calibration reset pending ......................................................... 311

Canceling <jobname> ............................................................. 312

Card slot device failure To clear touch “Clear” ........................... 312

Card slot file operation failed To clear touch “Clear” ................... 312

Card slot file system is full To clear touch “Clear” ........................ 312

Card slot is write protected To clear touch “Clear” ...................... 312

Card slot not initialized To clear touch “Clear” ........................... 312

Cartridge ship mode ................................................................ 313

Checking paper path ............................................................... 313

Chosen personality not available To continue, touch “OK” ........... 313

Clean the rollers ...................................................................... 313

Cleaning disk <X>% complete Do not power off ......................... 314

Cleaning do not grab paper ..................................................... 314

Cleaning... ............................................................................. 314

Clearing event log ................................................................... 314

Clearing paper path ................................................................ 314

Close front or right doors ......................................................... 315

Close lower right door ............................................................. 315

Close right door ...................................................................... 315

Creating cleaning page ........................................................... 315

Data received ......................................................................... 316

Digital send communication error .............................................. 316

Disk full Delete stored jobs ........................................................ 316

Disk low Delete stored jobs ....................................................... 316

Document feeder bin full .......................................................... 317

Document feeder is empty ........................................................ 317

Document Feeder Kit low .......................................................... 317

Document Feeder Kit very low ................................................... 317

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Document Feeder Kit very low To continue, touch “OK” ............... 317

Document feeder top cover open ............................................... 318

Event log is empty ................................................................... 318

Expected drive missing ............................................................. 318

Fax is disabled – ignoring call .................................................. 318

Flatbed cover open .................................................................. 318

Fuser Kit Low .......................................................................... 318

Fuser Kit very low .................................................................... 319

Fuser Kit very low To continue, touch “OK” ................................ 319

HP Secure Hard Drive disabled ................................................. 319

Incompatible <supply> ............................................................. 320

Incompatible supplies .............................................................. 320

Initializing scanner, please wait ................................................ 320

Initializing... ........................................................................... 320

Install <color> Cartridge .......................................................... 321

Install Fuser Unit ...................................................................... 321

Install supplies ........................................................................ 321

Internal disk device failure To clear touch “Clear” ....................... 322

Internal disk file operation failed To clear touch “Clear” ............... 322

Internal disk file system is full To clear touch “Clear” .................... 322

Internal disk is write protected To clear touch “Clear” .................. 322

Internal disk not found ............................................................. 322

Internal disk not functional ........................................................ 322

Internal disk not initialized To clear touch “Clear” ....................... 323

Internal disk spinning up .......................................................... 323

Load Tray 1 [Type] [Size] ......................................................... 323

Load Tray 1 [Type] [Size] To continue, touch “OK” ...................... 323

Load Tray <X>: [Size] .............................................................. 323

Load Tray <X>: [Size] To continue, touch “OK” .......................... 324

Load Tray <X>: [Size] To use another tray, touch "Options" ......... 324

Load Tray <X>: [Type], [Size] ................................................... 325

Load Tray <X>: [Type], [Size] To use another tray, touch

"Options" ............................................................................... 325

Manually feed output stack Then touch "OK" to print second

sides ...................................................................................... 325

Manually feed: [Size] .............................................................. 326

Manually feed: [Size] To continue, touch “OK” ........................... 326

Manually feed: [Size] To use another tray, touch "Options" .......... 326

Manually feed: [Type], [Size] To continue, touch “OK” ................ 327

Manually feed: [Type], [Size] To use another tray, touch

"Options" ............................................................................... 327

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Moving solenoid ..................................................................... 327

Moving solenoid and motor ...................................................... 327

No job to cancel ..................................................................... 327

Output Bin full ......................................................................... 328

Paperless mode ....................................................................... 328

Paused ................................................................................... 328

Performing Color Band Test… ................................................... 328

Performing Paper Path Test… .................................................... 328

Please wait… .......................................................................... 329

Printing CMYK samples... ......................................................... 329

Printing Color Usage Log... ...................................................... 329

Printing Configuration... ........................................................... 329

Printing Demo Page... .............................................................. 329

Printing Diagnostics Page... ...................................................... 329

Printing Engine Test... .............................................................. 330

Printing Event Log... ................................................................. 330

Printing File Directory... ............................................................ 330

Printing Font List... ................................................................... 330

Printing Fuser Test Page... ......................................................... 331

Printing Help Page... ............................................................... 331

Printing Menu Map... ............................................................... 331

Printing PQ Troubleshooting... .................................................. 331

Printing Registration Page... ...................................................... 331

Printing RGB Samples... ........................................................... 331

Printing stopped To continue, touch “OK” ................................... 332

Printing Supplies Status page... ................................................. 332

Printing Usage Page... ............................................................. 332

Processing digital send job ....................................................... 332

Processing duplex job... Do not grab paper until job completes .... 332

Processing job from tray <X>... Do not grab paper until job

completes ............................................................................... 333

Processing... <filename> .......................................................... 333

Processing... copy <X> of <Y> .................................................. 333

RAM Disk device failure To clear touch “Clear” .......................... 333

RAM Disk file operation failed To clear touch “Clear” .................. 333

RAM Disk file system is full To clear touch “Clear” ....................... 334

RAM Disk is write protected To clear touch “Clear” ..................... 334

RAM Disk not initialized To clear touch “Clear” .......................... 334

ReadyReady ........................................................................... 334

Ready <IP Address> ................................................................ 334

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Remove all toner cartridges To exit press X ................................. 335

Remove at least one toner cartridge To exit press X ..................... 335

Remove shipping lock from Tray 2 ............................................. 335

Replace <color> Cartridge ....................................................... 335

Replace Document Feeder Kit ................................................... 336

Replace Fuser Kit ..................................................................... 336

Replace staple cartridge ........................................................... 336

Replace supplies ..................................................................... 337

Replace Toner Collection Unit ................................................... 337

Restricted from printing in color ................................................. 339

Roller cleaning is recommended ................................................ 339

ROM disk device failed To clear touch “Clear” ........................... 340

ROM disk file operation failed To clear touch “Clear” .................. 340

ROM disk file system is full To clear touch “Clear” ....................... 340

ROM disk is write protected To clear touch “Clear” ..................... 340

ROM disk not initialized To clear touch “Clear” .......................... 340

Rotating <color> motor To exit press X ....................................... 341

Rotating Motor ........................................................................ 341

Size mismatch in Tray <X> ....................................................... 341

Sleep mode on ....................................................................... 342

Standard top output bin full Remove all paper from bin ................ 342

Staple Cartridge low ............................................................... 342

Staple Cartridge very low To continue, touch “OK” ..................... 342

Supplies in wrong positions ...................................................... 342

Supplies low ........................................................................... 343

Supplies very low To continue, touch “OK” ................................. 343

Toner Collection Unit almost full ................................................ 343

Toner Collection Unit full .......................................................... 343

Toner Collection Unit full To continue, touch “OK” ....................... 344

Tray 2 Lifting .......................................................................... 344

Tray <X> empty: [Size] ............................................................ 345

Tray <X> empty: [Type], [Size] ................................................. 345

Tray <X> open ........................................................................ 346

Tray <X> overfilled Remove excess paper .................................. 346

Tray <X> overfilled To use another tray, touch "Options" ............. 346

Type mismatch Tray <X> .......................................................... 346

Unable to cancel firmware update job ....................................... 347

Unable to install the firmware ................................................... 347

Unsupported drive installed ...................................................... 347

Unsupported supply in use ........................................................ 348

Unsupported supply installed .................................................... 348

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Unsupported supply installed To continue, touch “OK” ................. 348

Unsupported USB accessory detected Remove USB accessory ....... 348

Upgrade complete To continue turn off then on ........................... 349

USB accessory needs too much power Remove USB and turn off

then on .................................................................................. 349

USB accessory not functional .................................................... 349

USB hubs are not fully supported Some operations may not work

properly ................................................................................. 349

USB is write protected To clear touch “Clear” ............................. 349

USB needs too much power Remove USB and turn off then on ...... 350

USB not initialized To clear touch “Clear” .................................. 350

USB storage accessory removed Clearing any associated data ..... 350

USB storage device failure To clear touch “Clear” ....................... 350

USB storage file operation failed To clear touch “Clear” .............. 350

USB storage file system is full To clear touch “Clear” ................... 350

Used supply in use .................................................................. 351

Used supply installed To continue, touch “OK” ............................ 351

Warming up scanner ............................................................... 351

Wireless Configuration Mode ................................................... 351

Wireless is not configured ........................................................ 352

Wrong cartridge in <color> slot ................................................ 352

Event log messages ............................................................................................... 353

Print or view an event log ........................................................................ 354

Clear an event log .................................................................................. 354

Event log message table .......................................................................... 355

Clear jams .......................................................................................................................... 365

Common causes of jams ........................................................................................ 365

Auto-navigation for clearing jams ............................................................................ 366

Jam locations ........................................................................................................ 366

Clear jams in the document feeder .......................................................................... 367

Clear jams in the document feeder (M575c model) ................................................... 369

Clear jams in the output bin area ............................................................................ 371

Clear jams in Tray 1 .............................................................................................. 372

Clear jams in Tray 2 .............................................................................................. 374

Clear jams in the right door .................................................................................... 375

Clear jams in optional Tray 3 ................................................................................. 379

Clear jams in the lower right door (Tray 3) ............................................................... 380

Jam causes and solutions ....................................................................................... 381

Jams in the output bin ............................................................................. 381

Jams in the fuser and transfer area ........................................................... 381

Jams in the duplex area (duplex models) ................................................... 385

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Jams in Tray 1, Tray 2 and internal paper path .......................................... 386

Jams in Tray 3 ....................................................................................... 388

Paper feeds incorrectly or becomes jammed ............................................................................ 390

The product does not pick up paper ........................................................................ 390

The product picks up multiple sheets of paper ........................................................... 390

The document feeder jams, skews, or picks up multiple sheets of paper ....................... 391

Prevent paper jams ................................................................................................ 391

Use manual print modes ....................................................................................................... 392

Solve image quality problems ................................................................................................ 396

Image defects table ............................................................................................... 396

Clean the product ................................................................................................................ 402

Clean the control-panel display ............................................................................... 402

Print a cleaning page ............................................................................................ 402

Check the scanner glass for dirt or smudges ............................................................. 403

Clean the pickup rollers and separation pad in the document feeder ........................... 405

Solve performance problems ................................................................................................. 407

Solve connectivity problems ................................................................................................... 408

Solve USB connection problems .............................................................................. 408

Solve wired network problems ................................................................................ 408

The product has a poor physical connection. ............................................. 408

The computer is using the incorrect IP address for the product ...................... 408

The computer is unable to communicate with the product ............................ 409

The product is using incorrect link and duplex settings for the network .......... 409

New software programs might be causing compatibility problems ................ 409

The computer or workstation might be set up incorrectly .............................. 409

The product is disabled, or other network settings are incorrect .................... 409

Service mode functions ......................................................................................................... 410

Service menu ........................................................................................................ 410

Product resets ....................................................................................................... 413

Restore factory-set defaults ....................................................................... 413

Restore the service ID .............................................................................. 414

Product cold reset ................................................................................... 414

Format Disk and Partial Clean functions ................................................................... 415

Active and repository firmware locations ................................................... 415

Partial Clean ......................................................................................... 415

Execute a Partial Clean ............................................................ 416

Format Disk ........................................................................................... 416

Execute a Format Disk .............................................................. 417

Solve fax problems ............................................................................................................... 418

Checklist for solving fax problems ........................................................................... 418

What type of phone line are you using? .................................................... 418

ENWW xvii

Page 20

Are you using a surge-protection device? .................................................. 418

Are you using a phone company voice-messaging service or an answering

machine? .............................................................................................. 419

Does your phone line have a call-waiting feature? ...................................... 419

Check fax accessory status ..................................................................................... 420

General fax problems ............................................................................................ 421

Use Fax over VoIP networks .................................................................................... 422

Problems with receiving faxes ................................................................................. 423

Problems with sending faxes ................................................................................... 425

Fax error codes .................................................................................................... 427

Fax error messages on the product control panel ...................................................... 427

Send-fax messages ................................................................................. 428

Receive-fax messages ............................................................................. 429

Service settings ..................................................................................................... 430

Settings in the Troubleshooting menu ........................................................ 430

Product upgrades ................................................................................................................. 431

Determine the installed revision of firmware .............................................................. 431

Perform a firmware upgrade ................................................................................... 431

Embedded Web Server ........................................................................... 431

USB flash drive (Preboot menu) ................................................................ 432

USB flash drive (control-panel menu) ......................................................... 433

Web Jetadmin (WJA) .............................................................................. 434

Upload firmware files to WJA ................................................... 434

Appendix A Service and support ..................................................................................... 435

Hewlett-Packard limited warranty statement ............................................................................. 436

HP's Premium Protection Warranty: LaserJet toner cartridge limited warranty statement ................. 438

HP policy on non-HP supplies ................................................................................................ 439

HP anticounterfeit Web site ................................................................................................... 440

Color LaserJet Fuser Kit, Transfer Kit, and Roller Kit Limited Warranty Statement ........................... 441

Data stored on the toner cartridge .......................................................................................... 442

End User License Agreement .................................................................................................. 443

OpenSSL ............................................................................................................................. 446

Customer self-repair warranty service ..................................................................................... 447

Customer support ................................................................................................................. 448

Repack the product .............................................................................................................. 449

Prepare the product for shipping ............................................................................. 449

Repack the product ............................................................................................... 453

Appendix B Product specifications ................................................................................... 455

Physical specifications .......................................................................................................... 456

xviii ENWW

Page 21

Power consumption, electrical specifications, and acoustic emissions .......................................... 456

Environmental specifications .................................................................................................. 456

Appendix C Regulatory information ................................................................................. 457

FCC regulations ................................................................................................................... 458

Environmental product stewardship program ........................................................................... 459

Protecting the environment ...................................................................................... 459

Ozone production ................................................................................................. 459

Power consumption ............................................................................................... 459

Paper use ............................................................................................................. 459

Plastics ................................................................................................................. 459

HP LaserJet print supplies ....................................................................................... 459

Return and recycling instructions ............................................................................. 460

United States and Puerto Rico .................................................................. 460

Multiple returns (more than one cartridge) .................................. 460

Single returns .......................................................................... 460

Shipping ................................................................................ 460

Non-U.S. returns .................................................................................... 461

Paper .................................................................................................................. 461

Material restrictions ............................................................................................... 461

Disposal of waste equipment by users ...................................................................... 462

Electronic hardware recycling ................................................................................. 462

Chemical substances ............................................................................................. 462

Material Safety Data Sheet (MSDS) ......................................................................... 462

For more information ............................................................................................. 462

Declaration of conformity ...................................................................................................... 463

Declaration of conformity (fax models) .................................................................................... 465

Certificate of Volatility .......................................................................................................... 467

Certificate of Volatility (M575c) ............................................................................................. 469

Safety statements ................................................................................................................. 471

Laser safety .......................................................................................................... 471

Canadian DOC regulations .................................................................................... 471

VCCI statement (Japan) .......................................................................................... 471

Power cord instructions .......................................................................................... 471

Power cord statement (Japan) ................................................................................. 471

EMC statement (China) .......................................................................................... 472

EMC statement (Korea) .......................................................................................... 472

EMI statement (Taiwan) .......................................................................................... 472

Laser statement for Finland ..................................................................................... 472

GS statement (Germany) ........................................................................................ 474

Substances Table (China) ....................................................................................... 474

ENWW xix

Page 22

Restriction on Hazardous Substances statement (Turkey) ............................................. 474

Restriction on Hazardous Substances statement (Ukraine) ........................................... 474

Additional statements for telecom (fax) products ....................................................................... 475

EU Statement for Telecom Operation ....................................................................... 475

New Zealand Telecom Statements ........................................................................... 475

Additional FCC statement for telecom products (US) .................................................. 475

Telephone Consumer Protection Act (US) .................................................................. 476

Industry Canada CS-03 requirements ...................................................................... 476

Vietnam Telecom wired/wireless marking for ICTQC Type approved products ............. 477

Japan Telecom Mark ............................................................................................. 477

Index ............................................................................................................................... 479

xx ENWW

Page 23

List of tables

Table 1-1 Sequence of operation ............................................................................................................ 3

Table 1-2 Solenoids .............................................................................................................................. 5

Table 1-3 Switches ................................................................................................................................ 6

Table 1-4 Sensors ................................................................................................................................. 7

Table 1-5 Motors .................................................................................................................................. 8

Table 1-6 Fans ..................................................................................................................................... 9

Table 1-7 High-voltage power supply circuits ......................................................................................... 10

Table 1-8 Converted DC voltages ......................................................................................................... 12

Table 1-9 Fuser (fixing) components ...................................................................................................... 16

Table 1-10 Image formation process ..................................................................................................... 23

Table 1-11 Primary-transfer-roller engagement states ............................................................................... 33

Table 1-12 Image-stabilization controls .................................................................................................. 37

Table 1-13 Switches and sensors for the pickup, feed, and delivery system ................................................ 38

Table 1-14 Motors and solenoids for the pickup, feed, and delivery system ............................................... 39

Table 1-15 Jams that the product detects ............................................................................................... 54

Table 1-16 Electrical components for the paper feeder ............................................................................ 57

Table 1-17 Paper size detection ........................................................................................................... 60

Table 2-1 Preboot menu options (1 of 6) ................................................................................................ 85

Table 2-2 Preboot menu options (2 of 6) ................................................................................................ 87

Table 2-3 Preboot menu options (3 of 6) ................................................................................................ 88

Table 2-4 Preboot menu options (4 of 6) ................................................................................................ 89

Table 2-5 Preboot menu options (5 of 6) ................................................................................................ 89

Table 2-6 Preboot menu options (6 of 6) ................................................................................................ 90

Table 2-7 Troubleshooting flowchart ...................................................................................................... 93

Table 2-8 Heartbeat LED, product initialization ....................................................................................... 99

Table 2-9 Heartbeat LED, product operational ...................................................................................... 101

Table 2-10 Paper-path sensors diagnostic tests ..................................................................................... 106

Table 2-11 Ma

Table 2-12 Tray/bin manual sensors ................................................................................................... 122

Table 2-13 Component test details ...................................................................................................... 131

Table 2-14 Sensors ........................................................................................................................... 133

Table 2-15 DC controller connectors ................................................................................................... 134

nual sensor diagnostic tests ........................................................................................... 108

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Page 24

Table 2-16 Paper feeder driver PCA connectors ................................................................................... 135

Table 2-17 PCAs, motors, fans, switches, solenoids, and clutches ........................................................... 141

Table 2-18 Important information on the configuration pages ................................................................. 158

Table 2-19 Reports menu ................................................................................................................... 161

Table 2-20 General Settings menu ...................................................................................................... 163

Table 2-21 Copy Settings menu .......................................................................................................... 178

Table 2-22 Scan/Digital Send Settings menu ....................................................................................... 187

Table 2-23 Fax Settings menu ............................................................................................................ 199

Table 2-24 General Print Settings menu ............................................................................................... 212

Table 2-25 Default Print Options menu ................................................................................................ 214

Table 2-26 Display Settings menu ....................................................................................................... 216

Table 2-27 Manage Supplies menu .................................................................................................... 218

Table 2-28 Manage Trays menu ......................................................................................................... 224

Table 2-29 Network Settings menu ..................................................................................................... 226

Table 2-30 Jetdirect Menu .................................................................................................................. 227

Table 2-31 Troubleshooting menu ....................................................................................................... 240

Table 2-32 Backup/Restore menu ....................................................................................................... 245

Table 2-33 Calibration/Cleaning menu ............................................................................................... 245

Table 2-34 Causes and solutions for delivery delay jam ........................................................................ 381

Table 2-35 Causes and solutions for fuser delivery delay jams ............................................................... 381

Table 2-36 Causes and solutions for wrapping jams ............................................................................. 382

Table 2-37 Causes and solutions for fuser delivery stationary jams .......................................................... 382

Table 2-38 Causes and solutions for residual paper jams ...................................................................... 382

Table 2-39 Causes and solutions for pickup delay jams 2 ...................................................................... 383

Table 2-40 Causes and solutions for pickup stationary jams ................................................................... 384

Table 2-41 Causes and solutions for duplexing reverse jams .................................................................. 385

Table 2-42 Causes and solutions for duplex repick jams ........................................................................ 385

Table 2-43 Causes and solutions for residual media jams ...................................................................... 386

Table 2-44 Ca

Table 2-45 Causes and solutions for pickup stationary jams ................................................................... 387

Table 2-46 Causes and solutions for pickup delay jam 1; MP tray pickup ................................................ 387

Table 2-47 Causes and solutions for pickup delay and pickup stationary jams ......................................... 388

Table 2-48 Print modes under the Adjust Paper Types sub menu ............................................................. 393

Table 2-49 MP modes under the Optimize submenu ............................................................................. 394

Table 2-50 Image defects table .......................................................................................................... 396

Table 2-51 Solve performance problems .............................................................................................. 407

Table 2-52 Send-fax messages ........................................................................................................... 428

Table 2-53 Receive-fax messages ........................................................................................................ 429

Table B-1 Physical specifications ......................................................................................................... 456

Table B-2 Operating-environment specifications .................................................................................... 456

uses and solutions for pickup delay jam 1: tray pickup ..................................................... 386

xxii ENWW

Page 25

List of figures

Figure 1-1 Relationship between the main product systems ......................................................................... 2

Figure 1-2 Engine-control system ............................................................................................................. 4

Figure 1-3 DC controller block diagram ................................................................................................... 5

Figure 1-4 High-voltage power supply circuits ........................................................................................ 10

Figure 1-5 Low-voltage power-supply circuit ........................................................................................... 11

Figure 1-6 Fuser (fixing) components ..................................................................................................... 16

Figure 1-7 Fuser temperature-control circuit ............................................................................................ 17

Figure 1-8 Laser/scanner system ........................................................................................................... 20

Figure 1-9 Image formation system ........................................................................................................ 22

Figure 1-10 Image formation process .................................................................................................... 23

Figure 1-11 Pre-exposure ..................................................................................................................... 24

Figure 1-12 Primary charging ............................................................................................................... 24

Figure 1-13 Laser-beam exposure ......................................................................................................... 25

Figure 1-14 Development ..................................................................................................................... 25

Figure 1-15 Primary transfer ................................................................................................................. 26

Figure 1-16 Secondary transfer ............................................................................................................ 26

Figure 1-17 Separation ....................................................................................................................... 27

Figure 1-18 Fusing .............................................................................................................................. 27

Figure 1-19 ITB cleaning ...................................................................................................................... 28

Figure 1-20 Drum cleaning .................................................................................................................. 28

Figure 1-21 Toner-cartridge system ....................................................................................................... 29

Figure 1-22 Developing-roller engagement and disengagement control ..................................................... 30

Figure 1-23 ITB unit ............................................................................................................................. 32

Figure 1-24 Three states of primary-transfer-roller engagement and disengagement ..................................... 33

Figure 1-25 ITB cleaning process .......................................................................................................... 35

Figure 1-26 Toner patterns for calibration .............................................................................................. 36

Figure 1-27 Switches and sensors for the pickup, feed, and de

Figure 1-28 Motors and solenoids for the pickup, feed, and delivery system .............................................. 39

Figure 1-29 Three main units of the pickup, feed, and delivery system ....................................................... 40

Figure 1-30 Pickup-and-feed unit ........................................................................................................... 41

Figure 1-31 Tray-pickup mechanism ...................................................................................................... 42

Figure 1-32 Tray presence sensor ......................................................................................................... 43

livery system ............................................... 38

ENWW xxiii

Page 26

Figure 1-33 Tray lift mechanism ............................................................................................................ 44

Figure 1-34 Paper-level-detection mechanism .......................................................................................... 45

Figure 1-35 Multifeed prevention .......................................................................................................... 45

Figure 1-36 Multipurpose tray pickup mechanism ................................................................................... 46

Figure 1-37 Paper-feed mechanism ....................................................................................................... 47

Figure 1-38 Skew-feed prevention ......................................................................................................... 48

Figure 1-39 Fuser and delivery unit ....................................................................................................... 49

Figure 1-40 Loop-control mechanism ..................................................................................................... 50

Figure 1-41 Pressure-roller pressurization control .................................................................................... 51

Figure 1-42 Duplexing unit ................................................................................................................... 52

Figure 1-43 Jam detection sensors ........................................................................................................ 54

Figure 1-44 Optional paper feeder ....................................................................................................... 56

Figure 1-45 Signals for the paper feeder ............................................................................................... 57

Figure 1-46 Paper-feeder pickup and feed operation ............................................................................... 58

Figure 1-47 Paper size detection .......................................................................................................... 59

Figure 1-48 Paper-feeder lift ................................................................................................................. 61

Figure 1-49 Paper-feeder multiple feed prevention .................................................................................. 62

Figure 1-50 Jam detection .................................................................................................................... 64

Figure 1-51 Document feeder sensors (M575dn and 575f models) ........................................................... 66

Figure 1-52 Document feeder paper path (M575dn and 575f models) ...................................................... 67

Figure 1-53 Document feeder simplex operation (M575dn and 575f models) ............................................ 68

Figure 1-54 Document feeder duplex operation (first paper path; M575dn and 575f models) ...................... 69

Figure 1-55 Document feeder duplex operation (M575dn and 575f models) ............................................. 70

Figure 1-56 Document feeder sensors (M575c model) ............................................................................. 73

Figure 1-57 Document feeder paper path (M575c model) ....................................................................... 74

Figure 1-58 Document feeder deskew features ....................................................................................... 77

Figure 1-59 Document feeder open (book mode) .................................................................................... 78

Figure 1-60 Document feeder open (60º to 80º) ..................................................................................... 79

Figure 2-1 Diagnostic test (1 of 3) ....................................................................................................... 103

Figure 2-2 Diagnostic test (2 of 3) ....................................................................................................... 103

Figure 2-3 Dia

Figure 2-4 Engine-test button .............................................................................................................. 105

Figure 2-5 Test the front door switch (1 of 4) ........................................................................................ 109

Figure 2-6 Test the front door switch (2 of 4) ........................................................................................ 109

Figure 2-7 Test the front door switch (3 of 4) ........................................................................................ 110

Figure 2-8 Test the front door switch (4 of 4) ........................................................................................ 110

Figure 2-9 Test the registration sensor .................................................................................................. 111

Figure 2-10 Test the fuser loop sensors ................................................................................................ 112

Figure 2-11 Test the fuser pressure-release sensor (1 of 2) ...................................................................... 113

Figure 2-12 Test the fuser pressure-release sensor (2 of 2) ...................................................................... 113

Figure 2-13 Test the fuser output sensor (1 of 2) .................................................................................... 115

gnostic test (3 of 3) ....................................................................................................... 104

xxiv ENWW

Page 27

Figure 2-14 Test the fuser output sensor (2 of 2) .................................................................................... 115

Figure 2-15 Test the duplexer refeed sensor ......................................................................................... 117

Figure 2-16 Test the output-bin-full sensor ............................................................................................. 118

Figure 2-17 Test the ITB alienation sensor (1 of 2) ................................................................................. 120

Figure 2-18 Test the ITB alienation sensor (2 of 2) ................................................................................. 121

Figure 2-19 Test the Tray 1 paper sensor ............................................................................................. 123

Figure 2-20 Test the Tray 2 paper sensor ............................................................................................. 124

Figure 2-21 Test the Tray 2 sensor (1 of 2) ........................................................................................... 125

Figure 2-22 Test the Tray 2 sensor (2 of 2) ........................................................................................... 125

Figure 2-23 Test the Tray 2 lifter sensor ............................................................................................... 126

Figure 2-24 Test the optional Tray 3 paper sensor ................................................................................ 127

Figure 2-25 Test the optional Tray 3 feed sensor ................................................................................... 128

Figure 2-26 Test the optional Tray 3 paper surface sensor ..................................................................... 129

Figure 2-27 Test the optional Tray 3 SW1 paper size sensors ................................................................ 130

Figure 2-28 Sensors .......................................................................................................................... 133

Figure 2-29 DC controller PCA ........................................................................................................... 134

Figure 2-30 Paper feeder driver PCA ................................................................................................. 135

Figure 2-31 Component locations (1 of 5) ............................................................................................ 137

Figure 2-32 Component locations (2 of 5) ............................................................................................ 138

Figure 2-33 Component locations (3 of 5) ............................................................................................ 139

Figure 2-34 Component locations (4 of 5) ............................................................................................ 140

Figure 2-35 Component locations (5 of 5) ............................................................................................ 141

Figure 2-36 1 x 500 paper feeder ...................................................................................................... 143

Figure 2-37 General timing chart ........................................................................................................ 144

Figure 2-38 General circuit diagram (1 of 2) ....................................................................................... 145

Figure 2-39 General circuit diagram (2 of 2) ....................................................................................... 146

Figure 2-40 Product circuit block diagram ............................................................................................ 147

Figure 2-41 Paper feeder circuit diagram ............................................................................................ 148

Figure 2-42 Print-quality troubleshooting procedure ............................................................................... 149

Figure 2-43 Yellow print-quality troubleshooting page ........................................................................... 150

Figure 2-44 Yellow comparison pa

Figure 2-45 Black print-quality troubleshooting page ............................................................................. 151

Figure 2-46 Configuration page ......................................................................................................... 155

Figure 2-47 HP embedded Jetdirect page ............................................................................................ 157

Figure 2-48 Repetitive defects ruler ..................................................................................................... 159

Figure 2-49 Sample event log ............................................................................................................ 353

Figure 2-50 Clear jams form the document feeder (1 of 2) ..................................................................... 369

Figure 2-51 Clear jams form the document feeder (1 of 2) ..................................................................... 370

Figure A-1 Prepare the product for shipping (1 of 3) ............................................................................. 450

Figure A-2 Prepare the product for shipping (2 of 3) ............................................................................. 451

Figure A-3 Prepare the product for shipping (3 of 3) ............................................................................. 452

ge .................................................................................................. 150

ENWW xxv

Page 28

Figure C-1 Certificate of Volatility (1 of 2) ............................................................................................ 467

Figure C-2 Certificate of Volatility (2 of 2) ............................................................................................ 468

Figure C-3 Certificate of Volatility (M575c; 1 of 2) ............................................................................... 469

Figure C-4 Certificate of Volatility (M575c; 2 of 2) ............................................................................... 470

xxvi ENWW

Page 29

1 Theory of operation

Basic operation

●

Engine-control system

●

Laser/scanner system

●

Image formation system

●

Pickup, feed, and delivery system

●

Jam detection

●

Optional paper feeder

●

Scanning/image capture system

●

Stapler

ENWW 1

Page 30

Basic operation

The product routes all high-level processes through the formatter, which stores font information, processes the print image, and communicates with the host computer.

The basic product operation comprises the following systems:

The engine-control system, which includes the power supply and the DC controller printed circuit

●

assembly (PCA)

The laser/scanner system, which forms the latent image on the photosensitive drum

●

The image-formation system, which transfers a toner image onto the paper

●

The media feed system, which uses a system of rollers and belts to transport the paper through the

●

product

Option (optional paper feeder)

●

Figure 1-1 Relationship between the main product systems

Laser/scanner system

Engine control system

Image-formation system

Media-feed system

Option

2 Chapter 1 Theory of operation ENWW

Page 31

Sequence of operation

The DC controller PCA controls the operating sequence, as described in the following table.

NOTE: The terms fusing and fixing are synonymous.

Table 1-1 Sequence of operation

Period Duration Description

Waiting From the time the power is turned on,

the door is closed, or when the product exits Sleep mode until the product is ready for printing

Standby From the end of the waiting sequence or

the last rotation until the formatter receives a print command or until the product is turned off

Initial rotation From the time the formatter receives a

print command until the paper enters the paper path

Printing From the time the first sheet of paper

enters the paper path until the last sheet has passed through the fuser

Heats the fuser sleeve

●

Pressurizes the fuser pressure roller

●

Detects the toner cartridges

●

Detects the home position for the

●

primary transfer roller and the developing unit

Cleans the secondary transfer roller

●

Is in the READY state

●

Enters Sleep mode after the

●

specified length of time

Calibrates if it is time for an

●

automatic calibration

Activates the high-voltage power

●

supply

Prepares each laser/scanner unit

●

Warms the fuser to the correct

●

temperature

Forms the image on the

●

photosensitive drums

Transfers the toner to the paper

●

ENWW

Last rotation From the time the last sheet of paper

exits the fuser until the motors stop rotating

Fuses the toner image onto the

●

paper

Performs calibration after a

●

specified number of pages

Moves the last printed sheet into

●

the output bin

Stops each laser/scanner unit

●

Discharges the bias from the high-

●

voltage power supply

Basic operation

Page 32

Engine-control system

The engine-control system receives commands from the formatter and interacts with the other main systems to coordinate all product functions. The engine-control system consists of the following components:

DC controller

●

High-voltage power supply

●

Low-voltage power supply

●

Figure 1-2 Engine-control system

AC input

Fuse

Noise filter

DC controller

Fuse

Noise filter

Zero crossing

Switch

Rectifying

circuit

+5V

generation

circuit

Low-voltage power supply

circuit

Rectifying

circuit

Protection circuit

Switch

Fusing control

+24V

generation

circuit

Protection circuit

+3.3V

generation

circuit

+5VB

ICB

PSTYP100

/ZEROX

24VRMT

+24VB

+24VA

SW3

+24VB

+5VA

PWRSAVE

+3.3VA

VC5VOFF

VC3VOFF

Switch

+3.3VC

Switch

+3.3VB

+3.3VA

+5VB

+5VD

Power switch

PWRSWON

SW1

+5VC

SW2

Formatter

4 Chapter 1 Theory of operation ENWW

Page 33

DC controller

The DC controller controls the operational sequence of the printer.

Figure 1-3 DC controller block diagram

Solenoids

Table 1-2 Solenoids

Component abbreviation Component name

SL1 Primary transfer roller disengagement solenoid

SL2 Duplex reverse solenoid

SL3 Multipurpose-tray pickup solenoid

SL4 Tray pickup solenoid

Fuser

Laser/scanner

ENWW

Engine-control system

Page 34

Clutches

Switches

Table 1-3 Switches

Component abbreviation Component name

CL1 Duplex re-pickup clutch

Component abbreviation Component name

SW1, SW2 5V interlock switch

SW3 24V interlock switch

SW4 Power switch

Test print switch

6 Chapter 1 Theory of operation ENWW

Page 35

Sensors

Table 1-4 Sensors

Component abbreviation Component name

SR1 Drum home position sensor 1

SR2 Drum home position sensor 2

SR3 Drum home position sensor 3

SR5 Fuser (fixing) delivery sensor

SR6 Delivery tray media full sensor

SR7 Fuser (fixing) pressure release sensor

SR8 TOP (top of page) sensor

SR9 Tray-media-stack surface sensor

SR11 Developing home position sensor

SR13 Tray presence sensor

SR14 Loop sensor 1

SR15 Loop sensor 2

SR17 Primary-transfer-roller disengagement sensor

SR20 Tray-media presence sensor

SR21 MP-tray-media-presence sensor

SR22 Duplex re-pickup sensor

OHT sensor (in)

OHT sensor (out)

RD sensor (front)

RD sensor (rear)

Environmental sensor (temperature and humidity)

Yellow toner-level sensor

Magenta toner-level sensor

Cyan toner-level sensor

Black toner-level sensor

Toner collection-box-full sensor

Fuser (fixing) home-position sensor

ENWW

Engine-control system

Page 36

Motors and fans

The product has 11 motors and three fans. The motors drive the components in the paper-feed and image-formation systems. The fan motors cool the inside of the product.

Table 1-5 Motors

Abbreviation Name Purpose Type Failure detection

M2 Fuser (fixing) motor Drives the fuser (fixing)

roller, the delivery roller, and the fuser (fixing) pressure roller

M3 Drum motor 1 Drives the

photosensitive drum (yellow/magenta), developing unit (yellow), and primary charging roller (yellow/magenta)

M4 Drum motor 2 Drives the

photosensitive drum (cyan), developing unit (magenta/cyan), and primary charging roller (cyan)

M5 Drum motor 3 Drives the

photosensitive drum (black), developing unit (black), and ITB drive roller, and secondary transfer roller

M7 Lifter motor Drives the lifter for the

tray

DC motor Yes

M8 Cyan/black scanner

motor

M9 Yellow/magenta

scanner motor

M10 Developing

disengagement motor

M11 Duplex reverse motor Drives the duplex

Drives the scanner mirror in the cyan/ black laser scanner

Drives the scanner mirror in the yellow/ magenta laser scanner

Drives the developing unit disengagement

reverse roller and duplex feed roller

DC motor Yes

Stepping motor No

8 Chapter 1 Theory of operation ENWW

Page 37

Table 1-5 Motors (continued)

Abbreviation Name Purpose Type Failure detection

M12 Residual toner-feed

motor

M13 Pickup motor Drives the tray pickup

Table 1-6 Fans

Abbreviation Name Cooling area Type Speed

FM1 Power supply fan Around the power

FM2 Cartridge fan Around the cartridges Intake Full/half

FM3 Delivery fan Around the delivery

High-voltage power supply

Drives the residual toner feed screw

roller, MP tray pickup roller, feed roller, registration roller, and re-pickup roller

supply unit

unit

DC motor Yes

Stepping motor No

Intake Full/half

The high-voltage power supply delivers the high-voltage biases to the following components used to transfer toner during the image-formation process:

Primary-charging roller (in the cartridge)

●

Developing roller (in the cartridge)

●

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Engine-control system

Page 38

Primary-transfer roller

●

Secondary-transfer roller

●

Figure 1-4 High-voltage power supply circuits

The high-voltage power supply contains several separate circuits.

Table 1-7 High-voltage power supply circuits

Circuit Description

Primary-charging-bias generation DC negative bias is applied to the surface of the photosensitive drum to prepare it

for image formation.

Developing-bias generation DC negative bias adheres the toner to each photosensitive drum during the image-

formation process.

Primary-transfer-bias generation DC positive bias transfers the latent toner image from each photosensitive drum

onto the ITB.

Secondary-transfer-bias generation Two DC biases, one positive and one negative, transfer the toner from the ITB onto

the paper.

10 Chapter 1 Theory of operation ENWW

Page 39

Low-voltage power supply

The low-voltage power-supply circuit converts the AC power from the wall receptacle into the DC voltage that the product components use. The product has two low-voltage power-supplies for 110 Volt or 220 Volt input.

Figure 1-5 Low-voltage power-supply circuit

Fuser control

circuit

ENWW

The low-voltage power supply converts the AC power into three DC voltages, which it then subdivides, as described in the following table.

Engine-control system

Page 40

Table 1-8 Converted DC voltages

Main DC voltage Sub-voltage Behavior

+24V +24VA Stopped during Sleep (powersave)

mode

+24VB Interrupted when the front door or right

door open

Stopped during Sleep (powersave) mode

+5V +5VA Constantly supplied

3.3V is supplied during Sleep mode 2 or Sleep mode 3

+5VB 3.3V is supplied during Sleep mode 2

Stopped during Sleep mode 3

Power for the formatter

+5VC 3.3V is supplied during Sleep mode 2

or Sleep mode 3

Interrupted when the front door or right door open (SW1/SW2)

+5VD Stopped during Sleep mode

+3.3 V 3.3VA Constantly supplied

3.3VB Stopped only when the power is off

3.3VC Stopped during Sleep mode 2 or Sleep

24V Power Supply (24VRMT) signal: Controls supply or interruption of +24VA

●

5V Power supply (VC5VOFF) signal: Controls supply or interruption of +5VB

●

3V Power supply (VC3VOFF) signal: Controls supply or interruption of +3.3VB

●

Voltage conversion (PWRSAVE) signal: Converts output voltage of +5VA, +5VB and +5VC into

●

+3.3V

Overcurrent/overvoltage protection

Interrupted when the front door or right door open (SW1/SW2)

Power for the formatter

mode 3

The low-voltage power supply stops supplying the DC voltage to the product components whenever it detects excessive current or abnormal voltage from the power source.

12 Chapter 1 Theory of operation ENWW

Page 41

The low voltage power supply has a protective circuit against overcurrent and overvoltage to prevent failures in the power supply circuit. If DC voltage is not being supplied from the low voltage power supply, the protective function might be running. In this case, turn the power off and disconnect the power cable. Do not connect and turn on the product until the root cause is found and corrected. In additon, the low voltage power supply has two fuses (FU100/FU101) to protect against overcurrent. If overcurrent flows into the AC line, the fuse blows to stop AC power.

Safety

For personal safety, the low-voltage power supply interrupts power to the fuser, the high-voltage power supply, and the motors when the front door or right door open.

The product has AC power even when the power switch is turned off because the product uses a soft power switch. Be sure to disconnect the power cable before disassembling the product.

Voltage detection

The printer detects the power supply voltage that is connected to the printer. The DC controller monitors the input voltage from the power source so it can control the voltage to the fuser.

Sleep (powersave) mode

Sleep mode reduces the power consumption of the product. There are three sleep modes depending on the power consumption. The DC controller stops or converts each power supply according to the sleep mode:

Sleep mode 1: stops +24VA and +24VB

●

Sleep mode 2: stops +24VA, +24VB and +5VD. Converts +5VA and +5VC into +3.3V

●

Sleep mode 3: stops +24VA, +24VB, +5VB and +5VD. Converts +5VA and +5VC into +3.3V.

●

Power

consumption

Off Less than 0.5W Off Manually: press

Auto off Less than 1W Blinks at 3 second

Sleep Approximately 6W Blinks at 3 second

Status of power button light

intervals

How to enable mode

the power button

Automatically: sleep timer expires

Sleep timer expires

How to disable mode (put in Ready state)

Press the power button

Printing or network maintenance tasks

Relative time to Ready state

Longest

Longer than Sleep mode

Shortest

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Power supply voltage detection

The product detects the power supply voltage that is connected to the product. The DC controller monitors the POWER SUPPLY VOLTAGE (PSTYP100) signal and detects power supply voltage, whether 100V or 200V, to control the fusing operation properly.

Low-voltage power supply failure

The DC controller determines a low-voltage power supply failure and notifies the formatter when the low-voltage power supply does not supply +24V.

Power Off condition

The DC controller brings the product to a power off condition by 24V POWER SUPPLY (24VRMT) signal, 5V POWER SUPPLY (VC5VOFF) signal, 3V POWER SUPPLY (VC3VOFF) signal, and VOLTAGE CONVERSION (PWRSAVE) signal.

The +5VA and +5VC signals which are converted into +3.3V and +3.3VA, are supplied under the power off condition.

Auto on/Auto off mode

This feature conserves power after the product has been idle for an adjustable period of time. When the product is in this mode, the control-panel backlight is turned off, but the product retains all settings, downloaded fonts, and macros. The setting is disabled by default. The product enters this mode after a 60-minute idle time or by touching the sleep button.

Power

consumption

Off Less than 0.5W Off Manually:

Status of power button light

How to enable mode

press the power button

Automatically: sleep timer expires

How to disable mode (put in Ready state)

Press the power button

Relative time to Ready state

Longest

Controlpanel term

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Power

consumption

Status of power button light

How to enable mode

How to disable mode (put in Ready state)

Relative time to Ready state

Controlpanel term

Auto off Less than 1W Blinks at 3

second intervals

Sleep (A1W) Approximately6WBlinks at 3

second intervals

Sleep timer expires

Printing or network maintenance tasks

Insert or remove paper from the ADF

Open or close the scanner

Open the cartridge door

Touch the control panel touchscreen

Press the power button

Printing or network maintenance tasks

Insert or remove paper from the ADF

Longer than Sleep mode

Shortest All events

Network port

Open or close the scanner

Open the cartridge door

Touch the control panel touchscreen

Press the power button

NOTE: Product error messages override the Sleep message. The product enters sleep mode at the

appropriate time, but the error message continues to appear.

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Fuser (fixing) control

The fuser-control circuit controls the fuser temperature. The product uses an on-demand fusing method.

Figure 1-6 Fuser (fixing) components

Fuser sleeve

Table 1-9 Fuser (fixing) components

Type of component Abbreviation Name Function

Fuser control

FUSER HEATING

CONTROL signal

FUSER TEMPERATURE signal

circuit

Fuser heater safety circuit

Heaters H1 Fuser heater Heats the fuser sleeve.

Thermistors

(Contact type)

Thermoswitches

(Non-contact type)

TH1 Main thermistor The thermistor detects the center

temperature of the fuser sleeve.

TH2

TH3

TP1 For the fuser heater Controls the fuser-roller main

Sub thermistor Each thermistor detects the side

temperature of the fuser heater.

heater

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Fuser (fixing) temperature-control circuit

The temperatures of the two rollers in the fuser fluctuate according to the stage of the printing process. The DC controller sends commands to the fuser-control circuit to adjust temperatures.

Figure 1-7 Fuser temperature-control circuit

Fuser

Fuser sleeve unit

Fuser heater

control circuit

Fuser heater safety

circuit

Fuser

Fuser heater safety circuit

Fuser (fixing) over-temperature protection

To protect the fuser from excessive temperatures, the product has four layers of protective functions. If one function fails, the subsequent functions should detect the problem.

DC controller: When a thermistor or thermopile detects a temperature above a certain threshold,

●

the DC controller interrupts power to the specific heater. Following are the thresholds for each component:

TH1: 230° C (446° F) or higher

◦

TH2: 285° C (545° F) or higher

◦

Fuser control circuit

Fuser

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TH3: 285° C (545° F) or higher

◦

Fuser (fixing)-heater safety circuit: If the DC controller fails to interrupt the power to the

●

heaters at the prescribed temperatures, the fuser-heater safety circuit deactivates the triac-drive

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circuit and releases the relay, which causes the heaters to stop at slightly higher temperature thresholds.

TH2: 290° C (554° F) or higher

◦

TH3: 290° C (554° F) or higher

◦

Current-detection protection circuit: If current flowing in each triac exceeds a specific value,

●

the current-detection protection circuit deactivates the triac-drive circuit and releases the relay, which interrupts the power supply to the heaters.

Thermoswitch: If the temperature in the heaters is abnormally high, and the temperature in the

●

thermoswitches exceeds a specified value, the contact to the thermoswitch breaks. Breaking this contact deactivates the triac-drive circuit and releases the relay, which interrupts the power supply to the heaters. Following are the thresholds for each thermoswitch:

TP1: 270° C (518° F) or higher

◦

NOTE: When the thermoswitches reach this temperature, the temperature on the fuser rollers is about

320° C (608° F).

Fuser (fixing)-failure detection

When the DC controller detects any of the following conditions, it determines that the fuser has failed. The DC controller then interrupts power to the fuser heaters and notifies the formatter.

Abnormally high temperatures: Temperatures are too high for any of the following

●

components, at any time:

TH1: 230° C (446° F) or higher

◦

TH2: 285° C (545° F) or higher

◦

TH3: 285° C (545° F) or higher

◦

Abnormally low temperatures: Temperatures are too low at any of the following

●

components after the product has initialized.

TH1: 120° C (248° F) or lower

◦

TP2 or TP3: 100° C (212° F) or lower

◦

Or, the temperature drops in either of the thermopiles (TP2 and TP3) by 30° C (86° F) or more within a specified length of time.

Abnormal temperature rise: The DC controller determines an abnormal temperature rise if

●

the detected temperature of TH1 does not rise 2° C within a specified time period after the fuser (fixing) motor is turned on, or if the detected temperature of the thermistors does not rise to a specified temperature for a specified time after the fuser (fixing) motor is turned on.

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Thermistor open: The DC controller determines a thermistor open if:

●

The detected temperature of TH1 is kept at 12° C (53° F) or lower for a specified time after

◦

the fuser (fixing) motor is turned on.

The detected temperature of TH2 is kept at 4° C (39° F) or lower for a specified time.

◦

The detected temperature of TH3 is kept at 4° C (39° F) or lower for a specified time.

◦

Drive-circuit failure: The DC controller determines a drive-circuit failure:

●

If the detected power supply frequency is out of a specified range when the printer is turned

◦

on or during the standby period

If the current detection circuit detects an out of specified current value

◦

Fuser (fixing) discrepancy: The DC controller determines a fuser type mismatch when it

●

detects an unexpected fuser (fixing) unit presence signal. The product has two fusers for 110 V or 220 V input power.

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Laser/scanner system

The laser/scanner system forms the latent electrostatic image on the photosensitive drums according to the VIDEO signals sent from the formatter. The product has two laser/scanners: one for yellow and magenta and the other for cyan and black.

The formatter sends the DC controller instructions for the image of the page to be printed. The DC controller signals the lasers to emit light, and the laser beams pass through lenses and onto the scanner mirror, which rotates at a constant speed. The mirror reflects the beam onto the photosensitive drum in the pattern necessary for the image, exposing the surface of the drum so it can receive toner.

Figure 1-8 Laser/scanner system

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The DC controller determines that a laser/scanner has failed when any of the following conditions occurs:

Laser failure: The detected laser intensity does not match a specified value when the product

●

initializes.

Beam-detect (BD) failure: The BD interval is outside a specified range during printing.

●

Scanner-motor failure: The scanner motor does not reach a specified rotation speed within a

●

certain time after it begins rotating.

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Image formation system

The image-formation system creates the printed image on the paper. The system consists of the laser/ scanners, toner cartridges, imaging drums, ITB, and fuser.

Figure 1-9 Image formation system

Fuser

Laser/scanner

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Image formation process

The image-formation system consists of ten steps divided into six functional blocks.

Figure 1-10 Image formation process

Fusing

Fuser

Table 1-10 Image formation process

Functional block Steps Description

Latent image formation 1. Pre-exposure

2. Primary charging

3. Laser-beam exposure

Development 4. Development Toner adheres to the electrostatic latent

Transfer 5. Primary transfer

6. Secondary transfer

7. Separation

Fusing 8. Fusing The toner fuses to the paper to make a

ITB cleaning 9. ITB cleaning Residual toner is removed from the ITB.

Drum cleaning 10. Drum cleaning Residual toner is removed from the

An invisible latent image forms on the surface of the photosensitive drums.

image on the photosensitive drums.

The toner image transfers to the ITB and subsequently to the paper.

permanent image.

photosensitive drums.

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Step 1: Pre-exposure

Light from the pre-exposure LED strikes the surface of the photosensitive drum to remove any residual electrical charges from the drum surface.

Figure 1-11 Pre-exposure

Step 2: Primary charging

The primary-charging roller contacts the photosensitive drum and charges the drum with negative potential.

Figure 1-12 Primary charging

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Step 3: Laser-beam exposure

The laser beam strikes the surface of the photosensitive drum in the areas where the image will form. The negative charge neutralizes in those areas, which are then ready to accept toner.

Figure 1-13 Laser-beam exposure

Step 4: Development

Toner acquires a negative charge as the developing cylinder contacts the developing blade. Because the negatively charged surface of the photosensitive drums have been neutralized where they have been struck by the laser beam, the toner adheres to those areas on the drums. The latent image becomes visible on the surface of each drum.

Figure 1-14 Development

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Step 5: Primary transfer

The positively charged primary-transfer rollers contact the ITB, giving the ITB a positive charge. The ITB attracts the negatively charged toner from the surface of each photosensitive drum, and the complete toner image transfers onto the ITB, beginning with yellow, followed by magenta, cyan, and black.

Figure 1-15 Primary transfer

Step 6: Secondary transfer

The paper acquires a positive charge from the secondary-transfer roller, and so it attracts the negatively charged toner from the surface of the ITB. The complete toner image transfers onto the paper.

Figure 1-16 Secondary transfer

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Step 7: Separation

The stiffness of the paper causes it to separate from the ITB as the ITB bends. The static-charge eliminator removes excess charge from the paper to ensure that the toner fuses correctly.

Figure 1-17 Separation

Step 8: Fusing

To create the permanent image, the paper passes through heated, pressurized rollers to melt the toner onto the page.

Figure 1-18 Fusing

Fuser sleeve

Fuser heater

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Step 9: ITB cleaning

The cleaning blade scrapes the residual toner off the surface of the ITB. The residual-toner-feed screw deposits residual toner in the toner collection box.

Figure 1-19 ITB cleaning

Step 10: Drum cleaning

Inside the toner cartridge, the cleaning blade removes residual toner from the surface of the drum to prepare it for the next image. The waste toner falls into the hopper in the print cartridge.

Figure 1-20 Drum cleaning

Toner cartridge

The product has four toner cartridges, one for each color. Each toner cartridge contains a reservoir of toner and the following components:

Photosensitive drum

●

Developing roller

●

Primary-charging roller

●

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The DC controller rotates the drum motor to drive the photosensitive drum, developing roller, and the primary-charging roller.

Figure 1-21 Toner-cartridge system

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The DC controller rotates the drum motor to drive the photosensitive drum, developing unit, and primary charging roller.

The memory tag is a non-volatile memory chip that stores information about the usage for the toner cartridge.

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The DC controller notifies the formatter of an error if any of the following conditions exist:

The memory tag fails to either read to or write from the DC controller.

●

The RD sensors detect a missing or incorrectly installed toner cartridge.

●

The accumulated print time reaches a specified time period or the cartridge runs out of toner.

●

The toner level in any of the toner cartridges drops below a certain level.

●

Developing roller engagement and disengagement

The product can print in full-color mode or in black-only mode. To print in black-only mode, the product disengages the developing rollers in the cyan, magenta, and yellow toner cartridges. This maximizes the life of the cartridges.

Figure 1-22 Developing-roller engagement and disengagement control

Four developing units engaged

Only the Bk developing unit engaged

Four developing units disengaged

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The DC controller rotates the developing disengagement motor and changes the direction of the cam according to the instructions from the formatter for each print job.

When the product is turned on and at the end of each print job, all four of the developing rollers disengage from the photosensitive drums. If the next print job is full-color mode, each of the developing rollers engage. If the next print job is black-only mode, only the black developing roller engages.

If the DC controller does not detect any output from the developing home-position sensor, it determines that the developing-disengagement motor has failed.

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Intermediate transfer belt (ITB) unit

The ITB unit accepts the toner images from the photosensitive drums and transfers the completed image to the paper. The ITB unit has these main components:

ITB

●

ITB drive roller

●

ITB-driven roller

●

Primary-transfer rollers

●

ITB cleaner

●

The ITB motor drives the ITB drive roller, which rotates the ITB. The motion of the ITB causes the primary transfer rollers to rotate. The ITB cleaner cleans the ITB surface.

Figure 1-23 ITB unit

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Primary-transfer-roller engagement and disengagement

Depending on the requirements of the print job, the primary-transfer rollers engage with the ITB so it can receive toner from the photosensitive drums.

Figure 1-24 Three states of primary-transfer-roller engagement and disengagement

Fuser motor

Four colors are disengaged

FUSER MOTOR CONTROL

Four colors are engaged

Only black is engaged

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Table 1-11 Primary-transfer-roller engagement states

Roller state Product state

All rollers disengaged The home position for the ITB unit

All rollers engaged The state for a full-color print job

Black roller engaged The state for a black-only print job

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The primary-transfer-roller disengagement motor rotates or reverses to place the primary-transfer-roller disengagement cam into one of three positions. The cam causes the transfer-roller slide plate to move to the right or left. This movement causes the primary-transfer rollers to move up to engage the ITB with the photosensitive drum or down to disengage it.

If the DC controller does not receive the expected signal from the ITB home-position sensor when the primary-transfer-roller engages or disengages, but the primary-transfer-roller disengagement motor is rotating, the DC controller determines that the primary-transfer-disengagement mechanism has failed, and notifies the formatter.

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ITB cleaning

The cleaning blade in the ITB cleaner scrapes the residual toner off the ITB surface. The drum motor (M5) drives the residual toner feed screw. The screw feeds the residual toner to the residual toner feed unit. The residual toner feed motor (M12) drives the residual toner feed screw. The residual toner feed screw deposits the residual toner in the toner collection box. The DC control detects whether the toner collection box is full, using the toner collection-box-full sensor, and then notifies the formatter.

Figure 1-25 ITB cleaning process

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Calibration

The product calibrates itself to maintain excellent print quality. Calibration corrects color-misregistration and color-density variation.

During calibration, the product places a specific pattern of toner on the surface of the ITB. Sensors at the end of the ITB read the toner pattern to determine if adjustments are necessary.

Figure 1-26 Toner patterns for calibration

Color misregistration control

Internal variations in the laser/scanners can cause the toner images to become misaligned. The colormisregistration control corrects the following problems:

Horizontal scanning start position

●

Horizontal scanning magnification

●

Vertical scanning start position

●

The calibration occurs when any of the following occurs:

A cartridge is replaced.

●

The temperature of the sub thermistor is 50 C (122 F) or lower when the product recovers from

●

sleep mode after a specific number of pages print.

A specified number of pages have printed.

●

The formatter sends a command.

●

The user requests a calibration by using the control-panel menus.

●

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If data from the color-misregistration and image-density sensors is outside a specified range when the product is turned on or when it is beginning the calibration sequence, the DC controller determines that these sensors have failed, and it notifies the formatter.

Image stabilization control

Environmental changes or deterioration of the photosensitive drums and toner can cause variations in the image density. The image-stabilization control reduces these fluctuations. There are three kinds of image stabilization controls.

The formatter control is performed by the formatter.

Table 1-12 Image-stabilization controls

Image stabilization control Description

Environment change control The environment change control calibrates each high-voltage bias to obtain an

appropriate image according to the environment changes. The DC controller determines the environment where the product is installed based on the surrounding temperature and humidity data from the environment sensor, controls, and related biases. This control occurs under the following circumstances:

The toner cartridge is replaced.

●

The DC controller notifies the formatter when it encounters a communication error with the environmental sensor.

Image density control (DMAX) This control corrects variations in image density related to deterioration of the

photosensitive drum or the toner. The DC controller adjusts the high-voltage biases to correct the problem under the following conditions:

The sub thermistor detects a temperature that is too low when the product is

●

turned on.

After the print operation is completed for a specific period of the time.

●

A toner cartridge is replaced.

●

The ITB is replaced.

●

A specified number of pages have printed.

●

The formatter sends a command.

●

The environment is relatively charged.

●

Image halftone control (DHALF) The image halftone control is performed by the formatter. The DC controller

measures the halftone pattern according to the command from the formatter. The formatter performs this control to calibrate the halftone, based on the halftonedensity measurements, under the following conditions:

The formatter sends a command.

●

The DMAX is completed.

●

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The DC controller determines an RD sensor failure and notifies the formatter if it detects an out-ofspecified-data value from the RD sensor when the product is turned on or when the color misregistration control starts.

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Pickup, feed, and delivery system

The pickup, feed, and delivery system uses a series of rollers to move the paper through the product.

Figure 1-27 Switches and sensors for the pickup, feed, and delivery system

Table 1-13 Switches and sensors for the pickup, feed, and delivery system

Abbreviation Component

SR5 Fuser (fixing) delivery sensor

SR6 Delivery tray media full sensor

SR7 Fuser (fixing) pressure release sensor

SR8 TOP (top of page) sensor

SR9 Tray-media stack-surface sensor

SR13 Tray presence sensor

SR14 Loop sensor 1

SR15 Loop sensor 2

SR20 Tray media-presence sensor

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Table 1-13 Switches and sensors for the pickup, feed, and delivery system (continued)

Abbreviation Component

SR21 MP tray media-presence sensor

SR22 Duplex re-pickup sensor (duplex models only)

Figure 1-28 Motors and solenoids for the pickup, feed, and delivery system

Table 1-14 Motors and solenoids for the pickup, feed, and delivery system

Abbreviation Component

M2 Fuser (fixing) motor

M5 Drum motor 3

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M7 Lifter motor

M11 Duplex reverse motor (duplex models only)

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Table 1-14 Motors and solenoids for the pickup, feed, and delivery system (continued)

Abbreviation Component

M13 Pickup motor

CL1 Duplex re-pickup clutch (duplex models only)

SL2 Duplex reverse solenoid (duplex models only)

SL3 Multipurpose tray pickup solenoid

SL4 Tray pickup solenoid

Figure 1-29 Three main units of the pickup, feed, and delivery system

Fuser/delivery block

Duplex block

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Pickup-and-feed unit

The pickup-and-feed unit picks an individual sheet of paper from the multipurpose tray or the cassettes, carries it through the secondary-transfer unit, and feeds it into the fuser.

Figure 1-30 Pickup-and-feed unit

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Tray pickup

The sequence of steps for the tray pickup operation is the following:

1. When the product starts or the tray closes, the lifting mechanism lifts the paper stack so it is ready.

2. After receiving a print command from the formatter, the DC controller rotates the pickup motor,

3. The DC controller drives the tray pickup solenoid, which rotates the tray pickup cam. As the

Figure 1-31 Tray-pickup mechanism

which causes the tray pickup roller, tray feed roller, and tray separation roller to rotate.

pickup cam rotates, the pickup arm moves down, and the tray pickup roller touches the surface of the paper stack. The tray pickup roller then picks up one sheet of paper.

Tray

NOTE: The lift-up operation lifts the lifting plate to keep the stack surface of the media at a pickup

position. The lifting spring helps support the lifting plate depending on the media size and amount.

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Tray-presence detection

The tray presence sensor is in the lifter drive unit. The sensor detects the tray-presence sensor flag and determines whether the tray is installed correctly.

Figure 1-32 Tray presence sensor

Tray

Tray lift operation

The DC controller rotates the lifter motor (M7) and moves the lifter rack until the tray media stack surface sensor (SR9) detects it. The lifter lifts, and the lifting plate moves up to the position where the media can be picked up. The lift operation is performed by monitoring the media stack surface sensor when the printer is turned on, when the tray is installed, or as needed during a print operation.

If the paper-stack surface sensor does not detect the paper within a specified time after the lifter motor begins rotating, the DC controller notifies the formatter that the lifter motor has failed.

Tray

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The DC controller lowers the lifting plate when no printing occurs to prevent media damage and pickup failure. If a print operation does not occur for a specified time, the DC controller reverses the lifter motor and moves the lifter rack until the tray media-stack surface sensor stops detecting it.

Figure 1-33 Tray lift mechanism

Tray

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paper-presence detection

The media presence sensor detects whether paper is in the .

Figure 1-34 Paper-level-detection mechanism

Tray

Multifeed prevention

In the , a separation roller prevents multiple sheets of paper from entering the paper path. The pickup roller drives the separation roller through a sheet of paper.

Tray

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The low friction force between the sheets weakens the driving force from the pickup roller. Because some braking force is applied to the separation roller, the weak rotational force of the pickup roller is not enough to rotate the separation roller. Therefore, the separation roller holds back any multiple-fed sheets, and one sheet of media is fed into the printer.

Figure 1-35 Multifeed prevention

Cassette pickup roller

Cassette separation roller

Normal feed

Lifting plate

Media

Separation roller does not rotate

Multiple feed

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Multipurpose tray pickup

The multipurpose tray (MP) paper-presence sensor detects whether paper is in the tray. If no paper is present, the DC controller notifies the formatter. Printing does not occur until paper is in the tray.

The sequence of steps for the multipurpose tray pickup operation as follows:

1. After receiving a print command from the formatter, the DC controller reverses the pickup motor,

which causes the multipurpose tray separation roller to rotate.

2. The DC controller turns on the multipurpose tray pickup solenoid (SL3), causing the multipurpose

tray pickup roller to rotate.

3. The multipurpose tray separation roller isolates a single sheet of paper in case more than one

sheet was picked. The single sheet of paper feeds into the product.

The MP-tray media-presence sensor (SR21) detects whether the media is present in the MP tray. No printing occurs if no media is loaded.

Figure 1-36 Multipurpose tray pickup mechanism

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Paper feed

After the pickup operation, the paper feeds through the product and into the fuser.

1. The paper passes through the feed rollers. The registration shutter aligns the paper correctly to

2. The DC controller detects the leading edge of paper by the Top sensor (SR8) and controls the

3. The DC controller detects whether or not the media is overhead transparency, using the OHT

4. The toner image on the ITB transfers onto the media, which feeds to the fuser.

Figure 1-37 Paper-feed mechanism

prevent skewed printing.

rotational speed of the pickup motor to align with the leading edge of image on the ITB.

sensor.

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Skew-feed prevention

The product can straighten the paper without slowing the feed operation.

1. As the paper enters the paper path, the leading edge strikes the registration shutter, which

straightens the paper. The paper does not pass through the shutter.

2. The feed rollers keep pushing the paper, which creates a force on the leading edge against the

registration shutter.

3. When the force is great enough, the registration shutter opens and the paper passes through.

Figure 1-38 Skew-feed prevention

OHT detection

The OHT sensor detects overhead transparencies. The OHT sensor is a transmission sensor that uses an LED. The DC controller determines a media mismatch and notifies the formatter when the media type differs from the media type detected by the OHT sensor. The DC controller turns the LED in the OHT

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sensor on and off during the wait or initial rotation period. If the intensity of the light does not match the specified value, the DC controller determines that the OHT sensor has failed.

Fusing and delivery unit

The fusing and delivery unit fuses the toner onto the paper and delivers the printed page into the output bin. The following controls ensure optimum print quality:

Loop control

●

Pressure roller pressurization/depressurization control

●

A sensor detects when the output bin is full, and the DC controller notifies the formatter.

Figure 1-39 Fuser and delivery unit

Fuser/delivery block

Loop control

The loop control monitors the tension of the paper between the secondary-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.

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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.

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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 1-40 Loop-control mechanism

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Pressure-roller pressurization control

To prevent excessive wear on the pressure roller and help with jam-clearing procedures, the pressure roller pressurizes only during printing and standby. The DC controller reverses the fuser motor. The fuser motor rotates the fuser pressure-release cam.

Figure 1-41 Pressure-roller pressurization control

FUSER MOTOR CONTROL

Fuser motor

FUSER PRESSURE RELEASE signal

Fuser pressure release cam

Fuser sleeve

The pressure roller depressurizes under the following conditions:

The product is turned off with the on/off switch

●

Any failure occurs other than a fuser pressure-release mechanism failure

●

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During powersave mode

●

When a paper jam is detected

●

If the DC controller does not sense the fuser pressure-release sensor for a specified period after it reverses the fuser motor, it notifies the formatter that a fuser pressure-release mechanism failure has occurred.

NOTE: The fuser remains pressurized if the power is interrupted when the power cord is removed or

the surge protector is turned off, or if the fuser is removed without turning off the product.

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Duplexing unit

The duplexing unit reverses the paper and feeds it through the paper path to print the second side. The duplexing unit consists of the following components:

Duplexing-reverse unit: Installed on top of the product

●

Duplexing-feed unit: Along the right side

●

The DC controller controls the operational sequence of the duplex block. The DC controller drives each load, such as motors, solenoid, and clutch, depending on the duplex-reverse unit and duplex-feed unit controls.

Figure 1-42 Duplexing unit

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Duplexing reverse and feed control

The duplexing reverse procedure pulls the paper into the duplexing unit after it exits the fuser. The duplexing feed procedure moves the paper through the duplexer so it can enter the product paper path to print the second side of the page.

1. After the first side has printed, the duplexing flapper solenoid opens, which creates a paper path

into the duplexing-reverse unit.

2. After the paper has fully entered the duplexing-reverse unit, the duplexing-reverse motor reverses

and directs the paper into the duplexing-feed unit.

3. The duplexing re-pickup motor and duplexing feed motor move the paper into the duplexing re-

pickup unit.

4. To align the paper with the toner image on the ITB, the duplexing re-pickup motor stops and the

paper pauses.

5. The paper re-enters the paper path, and the second side prints.

Duplex pickup operation

The product has the following two duplex-media-feed modes depending on the media sizes:

One-sheet mode: Prints one sheet that is printed on two sides in one duplex print operation

●

Two-sheet mode: Prints two sheets that are printed on two-sides in one duplex print operation

●

(maximum paper size is A4)

The formatter specifies the duplex-media-feed mode.

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Pickup, feed, and delivery system

Page 82

Jam detection

The product uses the following sensors to detect the paper as it moves through the paper path and to report to the DC controller if the paper has jammed.

Fuser output sensor (SR5)

●

Registration sensor (SR8)

●

Fuser loop 1 (SR14)

●

Fuser loop 2 (SR15)

●

Duplexer refeed (SR22)

●

Figure 1-43 Jam detection sensors

The product determines that a jam has occurred if one of these sensors detects paper at an inappropriate time. The DC controller stops the print operation and notifies the formatter.

Table 1-15 Jams that the product detects

Jam Description

Pickup delay jam 1 pickup: The TOP sensor does not detect the leading edge of the paper within a specified

period after the pickup solenoid has turned on.

Multipurpose tray pickup: The TOP sensor does not detect the leading edge of the paper within a specified period after the multipurpose tray solenoid has turned on.

Pickup stationary jam The TOP sensor does not detect the trailing edge of the paper within a specified time from

when it detects the leading edge.

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Table 1-15 Jams that the product detects (continued)

Jam Description

Fuser delivery delay jam The fuser delivery paper-feed sensor does not detect the leading edge of the paper within a

specified period after the TOP sensor detects the leading edge.

Fuser delivery stationary jam The fuser delivery paper-feed sensor does not detect the trailing edge of the paper within a

specified period after it detects the leading edge.

Wrapping jam After detecting the leading edge of the paper, the fuser delivery paper-feed sensor detects the

absence of paper, and it has not yet detected the trailing edge.

Residual paper jam One of the following sensors detects paper presence during the initialization sequence:

Fuser delivery paper-feed sensor

●

TOP sensor

●

Loop sensor 1

●

Loop sensor 2

●

Duplex re-feed

●

Door open jam A door is opened while paper is moving through the product.

Duplexing re-pickup jam 1 The duplex re-pickup sensor does not detect the leading edge of the paper within a specified

period after the media reverse operation starts in the duplex-reverse unit.

Duplexing re-pickup jam 2 The TOP sensor does not detect the leading edge of the paper within a specified period after

the paper is re-picked.

After a jam, some sheets of paper might remain inside the product. If the DC controller detects residual paper after a door closes or after the product is turned on, the product automatically clears itself of those residual sheets.

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Jam detection

Page 84

Optional paper feeder

The 1x500-sheet paper feeder is optionally installed underneath the product. The paper feeder picks up the print media and feeds it to the printer.

NOTE: These optional trays are

Figure 1-44 Optional paper feeder

not

identical to the main (Tray 2).

The paper-deck drivers contain a microcomputer and control the paper feeder. The paper-deck drivers receive commands from the DC controller. If the DC controller is unable to communicate with a paperdeck driver, it notifies the formatter that the optional paper feeders are not connected correctly.

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Page 85

Figure 1-45 Signals for the paper feeder

The input trays contain several motors, solenoids, sensors, and switches, as described in the following table.

Table 1-16 Electrical components for the paper feeder

Component type

Motors M1 Paper feeder motor

Solenoids SL1 Paper feeder pickup solenoid

Sensors SR1 Tray 3 installed sensor

Switches SW1 Paper feeder media-size switch

Abbreviation Component name

M2 Paper feeder lift motor

SR2 Tray 3 stack surface sensor 2

SR3 Tray 3 paper present sensor

SR4 Tray 3 feed sensor

SW2 Paper-feeder door switch

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Optional paper feeder

Page 86

Paper-feeder pickup and feed operation

The paper feeder picks up one sheet from the paper-feeder and feeds it to the product.

Figure 1-46 Paper-feeder pickup and feed operation

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Paper size detection and presence detection

The paper-feeder media-size switch (SW1) detects the size of paper loaded in the paper-feeder . The paper-feeder driver determines the media size by monitoring the combination of the switches.

Figure 1-47 Paper size detection

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Tray

Optional paper feeder

Page 88

Table 1-17 Paper size detection

Paper size Paper-feeder media-size switch settings

Top switch Center switch Bottom switch

Universal On On On

A5 On Off Off

B5 Off On On

Executive On Off On

Letter Off On Off

A4 Off Off On

Legal On On Off

No Off Off Off

The paper-feeder media size switch (SW1) detects whether the paper-feeder is installed correctly. The paper-feeder driver determines if a is absent when all three switches are turned off. The paper-feeder driver determines a presence when one of the switches is turned on.

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Page 89

Paper feeder lift operation

The lift operation keeps the stack surface of paper at a specified height to maintain stable media feeding. The paper-feeder driver controls the paper-feeder lifter motor (M2) and monitors the paperfeeder media stack surface sensors (SR1, SR2) to adjust the stack height when the printer is turned on, when the printer recovers from sleep mode, when the paper-feeder is installed or as needed during a print operation. The paper feeder has two paper-feeder media-stack surface sensors. The paper-feeder media stack surface sensor 1 detects the stack height during a print operation. The paper-feeder mediastack surface sensor 2 detects the stack height when the printer is turned on, when the printer recovers from sleep mode and when the paper-feeder is installed. The operational sequence of the lift operation is as follows:

1. The paper-feeder driver rotates the paper-feeder lifter motor to lift the lifting plate.

2. The paper-feeder driver stops the paper-feeder lifter motor when the paper-feeder media-stack

surface sensor 2 detects the stack surface.

3. The paper-feeder driver rotates the lifter motor again when paper-feeder media stack surface 1

detects that the media surface is lowered during a print operation.

Figure 1-48 Paper-feeder lift

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The paper-feeder driver notifies the formatter if either of the paper-feeder media-stack surface sensors fails to detect the stack surface within a specified period from when a lift-up operation starts.

Optional paper feeder

Page 90

Paper feeder presence detection

The Tray 3 paper present (SR3) detects whether the paper is present in the paper-feeder .

Paper-feeder multiple feed prevention

The paper-feeder uses a separation roller to prevent multiple sheets of paper from entering the printer. The separation roller prevents multiple feeds of paper by allowing the paper-feeder separation roller to rotate in the same direction as the paper-feeder feed roller 1. The paper-feeder separation roller is equipped with the torque limiter. If multiple sheets of paper are picked up, the torque limiter takes control of the paper-feeder separation roller, and pushes the extra sheets back to the paper-feeder . That way, only the top sheet is fed to the printer.

Figure 1-49 Paper-feeder multiple feed prevention

No-load Rotational force for paper-feeder separation roller: Pushes

back the media into the paper-feeder

Rotational force for paper-feeder feed roller 1: Feeds media into the printer

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Normal feed Rotational force for paper-feeder separation roller: Pushes

back the media into the paper-feeder

Rotational force for paper-feeder feed roller 1: Feeds media into the printer

Multiple-feed The low friction force between the sheets weakens the

rotational force from the paper-feeder feed roller 1.

The paper-feeder separation roller rotates by its own rotational force and removes the extra sheet.

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Optional paper feeder

Page 92

Paper feeder jam detection

The paper feeder uses the Tray 3 feed (SR4) to detect the presence of paper and to check whether paper has jammed.

Figure 1-50 Jam detection

The paper-feeder driver identifies a jam if the sensor detects paper at a specified timing stored in the paper-feeder driver. The paper-feeder driver stops printing and notifies the formatter through the DC controller of the jam. The paper feeder detects the following jams:

Pickup delay jam: The paper-feeder media-feed sensor does not detect the leading edge of media

●

within a specified period from when the paper-feeder pickup solenoid is turned on.

Pickup stationary jam: The paper-feeder media-feed sensor does not detect the trailing edge of

●

media within a specified time period from when the sensor detects the leading edge.

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Page 93

Scanning/image capture system

Control panel

The control panel is a capacitive touchscreen with an adjustable viewing angle. The control panel assembly includes a USB port for walk-up printing and firmware upgrades. It also includes a hardware integration pocket for third-party USB devices such as card readers.

The control panel has the following features:

203.2 mm (8 in) full color SVGA (800 x 600 LCD) display

●

Physical external Home button

●

Ambient light sensor to automatically adjust brightness

●

Standalone diagnostic mode to assist troubleshooting

●

No calibration necessary

●

Full function QWERTY slide out keyboard (M575c model)

●

Scanner

The scanner is a carriage-type platen scanner which includes the frame, glass, scan module, and a scan controller board (SCB) attached to the back of the assembly. The scanner has a sensor to detect legal-sized media and a switch to indicate when the document feeder is opened.

The document feeder and control-panel assembly are attached to the scanner assembly. If the scanner fails, it can be replaced as a whole unit. The scanner replacement part does not include the document feeder, SCB, control-panel assembly, or control-panel cable.

Document feed system

This section describes the following:

Simplex single pass (all models)

●

Electronic duplexing (e-duplex) single pass (M575c model)

●

Document feeder operation (M575c model) on page 72

See

Duplex three pass M575dn and 575f model)

●

Legal-sensing flag

●

Pick and feed roller assembly with separation pad

●

Mechanical deskew

●

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Step glass for document feeder scanning

●

Scanning/image capture system

Page 94

Jam clearance door with sensing

●

LED indication when original is placed on input tray

●

Document feeder operation (M575dn and 575f models)

The following sections describe the operation of the document feeder for M575dn and 575f models.

Sensors in the document feeder (M575dn and 575f models)

The document feeder contains the following sensors:

ADF Y (length) sensor: Detects whether there is a legal-size original.

●

ADF paper present sensor: Detects whether a document is present in the document feeder. If

●

paper is present in the document feeder when copies are made, the product scans the document using the document feeder. If no paper is present when copies are made, the product scans the document using the scanner glass.

ADF paper path deskew sensor: Detects the top of the page as it enters the deskew rollers.

●

Prescan frontside sensor: Detects the top of the page as it approaches the document feeder

●

glass.

ADF jam cover sensor: Detects whether the document feeder cover is open or closed.

●

ADF pick success sensor: Detects the top of the page before sending a page through the ADF

●

and the end of the page after feeding/scanning is complete.

Figure 1-51 Document feeder sensors (M575dn and 575f models)

23 15

Item Description

1 ADF Y (length) sensor

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Page 95

Item Description

2 ADF pick success sensor

3 ADF paper path deskew sensor

4 Prescan frontside sensor

5 ADF jam cover sensor (open the jam acess-cover and insert a folded piece of paper to activate flag)

6 ADF paper present sensor

Document feeder paper path (M575dn and 575f models)

For two-sided documents, the delivery rollers reverse the direction of each page to feed the second side of the document past the document feeder glass.

Figure 1-52 Document feeder paper path (M575dn and 575f models)

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Item Description Item Description

1 Paper stopper 6 Deskew drive roller

2 Input tray 7 Output bin

3 Exit drive roller 8 Pinch-M-Duplex

4 Pick roller 9 Postscan drive roller

5 Feed roller 10 Prescan drive roller

Scanning/image capture system

Page 96

Document feeder simplex operation (M575dn and 575f models)

Following is the basic sequence of operation for a document feeder simplex job.

Figure 1-53 Document feeder simplex operation (M575dn and 575f models)

Document feeder simplex operation (M575dn and 575f models)

1. The ADF paper present sensor activates when paper is loaded into the input tray.

2. The pick motor rotates to lower the pick roller and starts to pick the loaded paper.

3. The ADF pick success sensor activated when leading edge of the paper is driven past the sensor.

The product firmware registers the leading edge of the paper position.

4. The leading edge of the paper is driven into the nip point of the deskew drive roller and the

deskew pinch rollers. A buckle of paper is created by the nip point for pick-skew correction. The product firmware registers the leading edge of the paper when the deskew sensor activates.

5. The deskew motor rotates the deskew drive roller to pull the paper into the prescan drive roller.

6. The pick motor stops turning and allows both the pick and feed roller to turn freely while the paper

is being pulled in by the deskew drive roller.

7. The feed motor rotates to drive the paper into the prescan frontside sensor. The firmware registers

the leading edge position of the paper as the prescan frontside sensor is activated.

8. The feed motor continues to rotate and drive the leading edge of the paper through the preset

distance from the prescan frontside sensor to the scan zone. The scanner begins the scanning and data retrieval process.

9. The prescan frontside sensor deactivates when trailing edge of the paper passes the sensor. The

firmware registers the trailing edge of the paper position.

10. The feed motor continues to rotate and drive the trailing edge of the paper through the preset

distance from the prescan frontside sensor to the scan zone. The scanner ends the scanning and data retrieval process.

11. The feed motor continues to rotate and ejects the trailing edge of the paper into the output bin.

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Page 97

Document feeder duplex operation (M575dn and 575f models)

Following is the basic sequence of operation for a document feeder duplex job.

Figure 1-54 Document feeder duplex operation (first paper path; M575dn and 575f models)

Document feeder duplex operation (M575dn and 575f models)

Following is a description of the first pass of a page during a duplex copy job. The front side of the page is scanned.

1. The ADF paper present sensor activates when paper is loaded into the input tray.

2. The pick motor rotates to lower the pick roller and starts to pick the loaded paper.

3. The ADF pick success sensor activated when leading edge of the paper is driven past the sensor.

The product firmware registers the leading edge of the paper position.

4. The leading edge of the paper is driven into the nip point of the deskew drive roller and the

deskew pinch rollers. A buckle of paper is created by the nip point for pick-skew correction. The product firmware registers the leading edge of the paper when the deskew sensor activates.

5. The deskew motor rotates the deskew drive roller to pull the paper into the prescan drive roller.

6. The pick motor stops turning and allows both the pick and feed rollers to turn freely while the

paper is being pulled in by the deskew drive roller.

7. The feed motor rotates to drive the paper into the prescan frontside sensor. The firmware registers

the leading edge position of the paper as the sensor prescan frontside sensor is activated.

8. The feed motor continues to rotate and drive the leading edge of the paper through the preset

distance from the prescan frontside sensor to the scan zone. The scanner begins the scanning and data retrieval process.

9. The prescan frontside sensor deactivates when trailing edge of the paper passes the sensor. The

firmware registers the trailing edge of the paper position.

10. The feed motor continues to rotate and drive the trailing edge of the paper through the preset

distance from the prescan frontside sensor to the scan zone. The scanner ends the scanning and data retrieval process.

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Scanning/image capture system

Page 98

Figure 1-55 Document feeder duplex operation (M575dn and 575f models)

Document feeder duplex operation (M575dn and 575f models)

Following is a description of the second pass of a page during a duplex copy job. The back side of the page is scanned.

1. The trailing edge of the paper travels a preset distance before pinch-m-duplex activates to pull the

paper back.

2. The deskew motor rotates the deskew drive roller to pull the paper into the prescan drive roller.

3. The feed motor rotates to drive the paper into the prescan sensor. The firmware registers the

leading edge position of the paper as the prescan frontside sensor is activated.

4. The feed motor continues to rotate and drive the leading edge of the paper through the preset

distance from the prescan frontside sensor to the scan zone. The scanner begins the scanning and data retrieval process.

5. The prescan frontside sensor deactivates when trailing edge of the paper passes the sensor. The

firmware registers the trailing edge of the paper position.

6. The feed motor continues to rotate and drive the trailing edge of the paper through the preset

distance from the prescan frontside sensor to the scan zone. The scanner ends the scanning and data retrieval process.

7. The trailing edge of the paper travels a preset distance before pinch-m-duplex activates to pull the

paper back.

Document feeder duplex operation (M575dn and 575f models)

Following is a description of the third pass of a page during a duplex copy job. The page is turned over and then moves to the output bin. This action allows the copy job to maintain the same page order as the source documents.

1. The deskew motor rotates the deskew drive roller to pull the paper into the prescan drive roller.

2. The feed motor rotates to drive the paper into the prescan frontside sensor.

3. The feed motor continues to rotate and drive the leading edge of the paper through the preset

distance from the prescan frontside sensor to the scan zone.

4. The prescan frontside sensor deactivates when trailing edge of the paper passes the sensor.

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Page 99

5. The feed motor continues to rotate and drive the trailing edge of the paper through the preset

distance from the prescan frontside sensor to the scan zone.

6. The feed motor continues to rotate and ejects the trailing edge of the paper into the output bin.

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Scanning/image capture system

Page 100

Document feeder operation (M575c model)

The following sections describe the operation of the document feeder for the M575c model.

The M575c product supports single page pass electronic duplexing (e-duplex) copy jobs.

The product uses two separate scan modules to scan the frontside and backside of an e-duplex copy job page in a single page pass thought the document feeder. See

(M575c model) on page 74.

For specific e-duplex copy jobs, a background selector changes the reflective platen from a white strip to a black strip for page edge-to edge recognition. See

(M575c model) on page 76.

Sensors in the document feeder (M575c model)

The document feeder contains the following sensors:

ADF Y (length) sensor: Detects whether there is a legal-size original.

●

ADF paper present sensor: Detects whether a document is present in the document feeder. If

●

Document feeder paper path

Frontside and backside background selector

ADF multi pick (ultra sonic) sensor: Uses ultra sonic sound to detect a mutli page paper

●

feed.

NOTE: This sensor also functions as the pick success sensor.

ADF paper path deskew sensor: Detects the top of the page as it enters the deskew rollers.

●

Prescan frontside sensor: Detects the top of the page as it approaches the frontside scan

●

module (document feeder glass).

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HP Color Laserjet M575 troubleshooting manual

Specifications and Main Features

Frequently Asked Questions

User Manual

1 Theory of operation

Basic operation

Sequence of operation

Engine-control system

DC controller

Solenoids

Clutches

Switches

Sensors

Motors and fans

High-voltage power supply

Low-voltage power supply

Overcurrent/overvoltage protection

Safety

Voltage detection

Sleep (powersave) mode

Power supply voltage detection

Low-voltage power supply failure

Power Off condition

Auto on/Auto off mode

Fuser (fixing) control

Fuser (fixing) temperature-control circuit

Fuser (fixing) over-temperature protection

Fuser (fixing)-failure detection

Laser/scanner system

Image formation system

Image formation process

Step 1: Pre-exposure

Step 2: Primary charging

Step 3: Laser-beam exposure

Step 4: Development

Step 5: Primary transfer

Step 6: Secondary transfer

Step 7: Separation

Step 8: Fusing

Step 9: ITB cleaning

Step 10: Drum cleaning

Toner cartridge

Developing roller engagement and disengagement

Intermediate transfer belt (ITB) unit

Primary-transfer-roller engagement and disengagement

ITB cleaning

Calibration

Color misregistration control

Image stabilization control

Pickup, feed, and delivery system

Pickup-and-feed unit

Tray pickup

Tray-presence detection

Tray lift operation

paper-presence detection

Multifeed prevention

Multipurpose tray pickup

Paper feed

Skew-feed prevention

OHT detection

Fusing and delivery unit

Loop control

Pressure-roller pressurization control

Duplexing unit

Duplexing reverse and feed control

Duplex pickup operation

Jam detection

Optional paper feeder

Paper-feeder pickup and feed operation

Paper size detection and presence detection

Paper feeder lift operation

Paper feeder presence detection

Paper-feeder multiple feed prevention

Paper feeder jam detection

Scanning/image capture system

Control panel

Scanner

Document feed system

Document feeder operation (M575dn and 575f models)

Sensors in the document feeder (M575dn and 575f models)