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Lexmark C920 Service Manual - Page 138

Fusing

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5056-XXX Fusing Once the paper has been imaged, the paper is detached from the transfer belt by the separation fingers. After separation, it enters the fuser where heat and pressure are applied to the paper. The toner is melted and bonded to the fibers of the paper. Note: The fuser's upper and lower fuser rollers are heated and pressure-fitted. A heater is positioned in the roller tube, and a thermistor and thermostat remain in contact with the outside of the tube. Fuser separation fingers are attached near the upper roller to separate the paper from the roller. Each thermistor sends the surface temperature of the roller to the printer controller. The printer controller turns the heater on or off according to the voltage of each thermistor. If the controller fails and the temperature of the roller exceeds specifications, the temperature fuse (TCO) connected to each heater opens, preventing overheating. 3-26 Service Manual

Section	Page
Table of contents	3
Notices and safety information	13
Laser notice	13
Laser	13
Avis relatif à l’utilisation de laser	13
Avvertenze sui prodotti laser	13
Avisos sobre el láser	14
Declaração sobre Laser	14
Laserinformatie	14
Lasermeddelelse	14
Huomautus laserlaitteesta	15
Laser-notis	15
Laser-melding	15
Avís sobre el Làser	15
Consignes de sécurité	17
Norme di sicurezza	17
Sicherheitshinweise	18
Pautas de Seguridad	18
Informações de Segurança	18
Informació de Seguretat	19
Preface	20
1. General information	21
Overview	21
Resolution	21
Model differences	21
Options and features	22
Technical specifications	23
Toner darkness	23
Color correction settings	23
Physical specifications and weight	23
Print speed and performance	24
Performance	25
Time to first print	25
Processor	25
Duty cycle	25
Printer memory	26
Resident fonts	26
Paper and media specifications	27
Media size supported	28
Input media types and weights	32
Input capacity by media and source	33
Output capacity by media and source	34
Media guidelines	35
Print area	35
Connectivity	36
Standard	36
Network connections	36
Data streams	36
Operating systems	36
Power and electrical specifications	37
Power requirements	37
Operating clearances	38
Environment	38
Printer temperature and humidity	38
Maintenance approach	39
Standard inspection and cleaning procedure	39
Return parts	40
Service recommendations	40
Tools	40
Serial number, configuration ID, and part number	40
Acronyms	41
2. Diagnostic information	43
Start	43
Initial check	43
Symptom table	45
Printer messages	47
Service error message tables	47
Attendance messages	72
Maintenance analysis procedures (MAPS)	85
Service checks	92
Drive 1 DC motor service check	92
Paper exit motor service check	92
Duplex unit service check	92
Paper feed unit service check	93
Expansion paper feed service check	94
Face down stacker full service check	94
High-capacity feeder (HCF) service check	95
Finisher service check	96
Marks on paper service check	97
Operator panel service check	97
Paper carrying service check	98
Paper exit, face up service check	102
Paper skew service check	102
Paper tray missing service check	102
Photodeveloper missing service check	103
Power supply service check	103
210 Staple jam service check	104
Transfer belt up/down service check	104
Image quality troubleshooting	105
Print quality problems	105
Options service check	110
3. Diagnostic aids	113
Power-On Self Test sequence	113
Understanding the printer operator panel	114
Printing the menu settings	115
Operator menu disabled	115
Menu overview	116
Diagnostics	117
Alignment	119
Print Tests	120
Hardware Tests	120
Output Bin Tests	125
Finisher Tests	126
Device Tests	128
Printer Setup	129
Event Log	132
Exit Diagnostics	132
Configuration menu	133
Black only mode	133
Print quality pages	133
Color trapping	133
Panel menus	133
PPDS emulation	133
Demo mode	133
Factory defaults	134
Energy conserve	134
Event log	134
Auto align adjust	134
Auto color adjust	134
Paper prompts	134
Envelope prompts	134
Jobs on disk	135
Disk encryption	135
Font sharpening	135
Standby disabled	135
Exit config menu	135
Theory of operation	136
Processes and configuration	136
Electrophotography process	136
Development unit	136
Transfer unit	137
Cleaning unit	137
Fusing	138
Drive system	140
Paper feeding	141
Cassette paper feeder	141
Multipurpose feeding	142
Registration unit	142
Belt unit	143
Belt up/down	143
Delivery	144
Expansion paper feeder	144
Duplex unit	144
Paper weight	145
Clearing paper jams	146
High-capacity feeder (HCF)	150
Maintenance Mode	155
Finisher	156
Finisher installation	164
Attaching the docking plate and guide rail	164
Combining the finisher and stand	166
Attaching the bins	170
Aligning the finisher and printer	171
Adjusting the wheels	176
Attaching the cables	177
Hole punch adjustment	181
4. Repair information	183
Handling ESD-sensitive parts	183
Service precautions	183
RIP board/operator panel replacement	184
Handling printed circuit boards	184
Check finisher alignment when moving or servicing the finisher	185
Adjustments	186
High-capacity paper feed timing belt adjustment	186
Adjustments and procedures following parts replacement	186
Removals	188
Cover, top removal	188
Front door / operator panel removal	189
Cover, front left removal	190
Cover, rear removal	191
Cover, solenoid removal	191
Cover, left side removal	191
Cover, right side removal	192
Cover, RIP board removal	193
Tray, paper exit removal	194
Belt up/down clutch removal	194
Cassette guide removal	195
CK1 daughter board removal	195
CK2 daughter board removal	195
Connector, duplex unit removal	196
Paper tray lift motor removal	196
Density sensor removal/Separation fingers removal/Sensor cleaner removal	197
Drive gear unit sensor assembly removal	197
Electronic box removal	198
Face up paper exit assembly removal	199
Front cover open switch actuator removal	199
Fuser removal	200
Gear cover removal/Multipurpose feeder frame assembly	201
High voltage power supply board (HVPS) removal	202
LED printhead removal	202
Eraser removal	203
Lock handle assembly removal	204
Main drive unit removal	205
Main unit fan removal	207
Motor drive board removal	207
Multipurpose feeder paper present sensor removal	207
Multipurpose feeder tray removal	208
Paper feed unit removal	208
Paper-feed rollers removal	210
Paper carrying frame removal / roll removal	211
Registration frame	212
Registration clutch removal	212
Registration sensor removal	212
Relay roller removal	213
Face down guide assembly removal	214
Face down exit roll removal	214
Power supply 1 removal	217
Power supply 2 removal	218
Power switch removal	219
Printer controller removal	219
Printhead controller board removal	220
Left slide rail removal	221
RIP box removal	221
Sensor board removal	222
Stay arm removal	222
Sub-frame removal	223
Sub frame F1, sub frame F2 removal	224
Temperature/humidity sensor removal	224
Top unit removal	225
Transfer belt removal	225
Turn guide cover sensor removal	229
Upper fan removal	229
Expansion feeder removals	231
Turn guide door removal	231
Expansion feeder controller board removal	231
Size sensor board removal	231
Stepper motor removal	232
Paper feed assembly removal	233
Paper tray lift motor removal	234
Expansion feeder turn guide door sensor assembly removal	234
Duplex removals	235
Duplex unit separation removal	235
Duplex unit removal	236
Duplex timing belt removal	236
Duplex pressure roller and solenoid removal	237
Duplex feed roller and solenoid removal	237
Duplex side fence motor assembly/side fence removal	238
Duplex paper carrying motor removal	239
High-capacity feeder (HCF) removals	240
HCF covers removal	240
HCF call roller, paper feed roller, reverse roller removal	241
HCF pickup solenoid removal	241
HCF paper end sensor removal	242
HCF paper size sensors (1, 2) removal	242
HCF tray motor removal	243
HCF paper level sensor removal	244
HCF power supply removal	244
Finisher removals	245
External covers removals	245
Finisher control board removal	246
Elevator motor removal	247
Feed motor assembly removal	247
Hole punch removal	248
Inverter paper exit discharge brush removal	249
Inverter paper exit roller removal	249
Jogging unit removal	250
Path select gate removal	251
Patting roller removal	252
Power supply removal	254
Registration roller removal	255
Registration roller clutch removal	255
Stack area discharge brush removal	256
Staple unit removal	256
Straight paper exit discharge brush removal	257
Straight paper exit roller removal	257
Timing belts 1 and 2 removal	259
Tractor belt removal	260
Tractor drive motor assembly removal	261
5. Locations	263
Covers diagram	263
Major parts diagram	264
Sensor and switch locations	265
Component locations	266
Printer controller board	267
Printer controller board connectors	268
Printhead controller board	269
Printhead controller board connectors	270
LVPS 1 board connectors	274
LVPS 2 board connectors	275
High voltage power supply board	276
Sensor board connectors	276
Duplex unit controller board	278
Motor drive board connectors	278
Size sensor board	279
Paper feed actuators	280
Paper feed roller clutch	280
High-capacity feeder (HCF)	281
High-capacity paper feed configuration	281
Electrical parts layout	282
Driving parts layout	282
Finisher locations	283
6. Preventive maintenance	287
Maintenance kit	287
Paper path maintenance	287
Periodic maintenance	288
Lubricants and cleaners	288
7. Parts catalog	289
How to use this parts catalog	289
Assembly 1: Covers 1	290
Assembly 2: Covers 2	292
Assembly 3: Covers 3	293
Assembly 4: Covers 4	294
Assembly 5: Covers 5	295
Assembly 6: Upper unit	296
Assembly 7: Paper feed	298
Assembly 8: Base 2	300
Assembly 9: Base 3	302
Assembly 10: Electrical A	304
Assembly 11: Electrical B	308
Assembly 12: RIP board	310
Assembly 13: Fuser unit	311
Assembly 14: Cassette	312
Assembly 15: Expansion feeder 1	314
Assembly 16: Expansion feeder 2	316
Assembly 17: Duplex unit 1	318
Assembly 18: Duplex Unit 1	319
Assembly 19: Duplex unit 2	320
Assembly 20: High-capacity feeder 1	322
Assembly 21: High-capacity feeder 2	324
Assembly 22: High-capacity feeder 3	326
Assembly 23: High-capacity feeder 4	328
Assembly 24: High-capacity feeder 5	330
Assembly 25: High-capacity feeder 6	332
Assembly 26: Finisher covers	334
Assembly 27: Finisher frame	336
Assembly 28: Finisher feed 1	338
Assembly 29: Finisher feed 2	340
Assembly 30: Finisher elevator	341
Assembly 31: Finisher electronics	342
Assembly 32: Finisher docking 1	343
Assembly 33: Finisher docking 2	344
Assembly 34: Miscellaneous/options	345
Assembly 35: Parts packets	346
Assembly 36: Finisher parts packet P/N 56P9480	351
Index	353
Part number index	361

Match case Limit results 1 per page

3-26

Service Manual

5056-

XXX

Fusing

Once the paper has been imaged, the paper is detached from the transfer belt by the separation fingers.

After separation, it enters the fuser where heat and pressure are applied to the paper. The toner is melted and

bonded to the fibers of the paper.

Note:

The fuser’s upper and lower fuser rollers are heated and pressure-fitted. A heater is positioned in

the roller tube, and a thermistor and thermostat remain in contact with the outside of the tube. Fuser

separation fingers are attached near the upper roller to separate the paper from the roller. Each thermistor

sends the surface temperature of the roller to the printer controller. The printer controller turns the heater

on or off according to the voltage of each thermistor. If the controller fails and the temperature of the roller

exceeds specifications, the temperature fuse (TCO) connected to each heater opens, preventing

overheating.