Xerox 1235DT - Phaser Color Solid Ink Printer User manual

Warning
The following servicing instructions are for
use by qualified service personnel only. To
avoid personal injury, do not perform any
servicing other than that contained in
operating instructions unless you are qualified
to do so.
This printing: December 2000
071-0728-00
PHASER® 1235
NETWORK COLOR PRINTER
Service Guide

Users safety summary
Terms in CAUTION Conditions that can result in damage to the product.
manual: WARNING Conditions that can result in personal injury
or loss of life.
Power source: For 110 VAC printers, Do not apply more than 140 volts RMS
between the supply conductors or between either supply conductor and ground.
Use only the specified power cord and connector. For 220 VAC printers, do not
apply more than 260 volts RMS between the supply conductors or between either
supply conductor and ground. Use only the specified power cord and connector.
Refer to a qualified service technician for changes to the cord or connector.
Operation of product: Avoid electric shock by contacting a qualified service
technician to replace fuses inside the product. Do not operate without the covers
and panels properly installed. Do not operate in an atmosphere of explosive
gases.
Safety instructions: Read all installation instructions carefully before you plug the
product into a power source.
Terms on CAUTION A personal injury hazard exists that may not be
product: apparent. For example, a panel may cover the hazardous area.
Also applies to a hazard to property including the product itself.
DANGER A personal injury hazard exists in the area where
you see the sign.
Care of product: Disconnect the power plug by pulling the plug, not the cord.
Disconnect the power plug if the power cord or plug is frayed or otherwise
damaged, if you spill anything into the case, if product is exposed to any excess
moisture, if product is dropped or damaged, if you suspect that the product needs
servicing or repair, and whenever you clean the product.
Ground the product: Plug the three-wire power cord (with grounding prong) into
grounded AC outlets only. If necessary, contact a licensed electrician to install a
properly grounded outlet.

Symbols as marked on product:
DANGER high voltage:
Protective ground (earth) terminal:
Use caution. Refer to the manual(s) for information:
WARNING:
If the product loses the ground connection, usage of knobs and
controls (and other conductive parts) can cause an electrical shock. Electrical
product may be hazardous if misused.
Service safety summary
For qualified service personnel only:
Refer also to the preceding Users Safety
Summary.
Do not service alone:
Do not perform internal service or adjustment of this
product unless another person capable of rendering first aid or resuscitation is
present.
Use care when servicing with power on:
Dangerous voltages may exist at several
points in this product. To avoid personal injury, do not touch exposed
connections and components while power is on.
Disconnect power before removing the power supply shield, soldering, or
replacing components.
Do not wear jewelry:
Remove jewelry prior to servicing. Rings, necklaces, and
other metallic objects could come into contact with dangerous voltages and
currents.
Power source:
This product is intended to operate from a power source that will
not apply more than 120 or 250 volts rms (depending on printer model) between
the supply conductors or between either supply conductor and ground. A
protective ground connection by way of the grounding conductor in the power
cord is essential for safe operation.
!

Service Guide
v
Contents
General Information 1
The Phaser 1235 Color Printer 2
Printer RAM and printer capabilities 4
CRU life counter behavior 4
Print engine assemblies 5
The image processor board 11
The control panel 12
On Line LED 12
! Fault 12
Rear panel 13
Accessing special operating modes 14
System controller board LEDs 14
Paper tray type sensing 15
Specifications 16
Regulatory specifications 19
Error Codes and Messages 21
Error messages 21
Troubleshooting 31
Power on self-diagnostic test 32
Print engine troubleshooting 33
Testing the print engine 33
Verifying printer operation by using its self-test print 34
Verifying power supply operation 34
Measuring power supply voltages 34
Inspecting the low-voltage power supply fuse 36
Safety interlocks 36
Testing for a shorted motor 37
Motor and fuser roller resistances 38
Media jams and the paper path 39
Media-based problems 39
Media problems 39
Multiple-sheet pick 39
The media skews passing through the paper path 40
Paper tray indicates it is empty when it is not 40

vi
Phaser 1235 Network Color Printer
Jams 41
Wrong media 41
Paper jams at the paper tray 41
Manual bypass feeder feed jams 42
Paper jams at the registration rollers 42
Paper jams at the transfer belt 42
Fuser jams 43
Eject jams 43
Jams in the duplex unit 43
No drum imaging unit installed 44
Imaging drum unit up/down error 44
Fan error 44
Fuser unit error 45
Other problems 46
The printer continuously displays “Booting” or “Initializing.” 46
False “No toner cartridge installed” message 46
False “No fuser unit installed” message 46
Front door indicated being open when it is closed 47
High temperature error 47
Low temperature error 47
Invalid memory DIMM 47
Printing and print quality problems 48
Light or blurred images 48
Dark, stained background 49
Blank print 50
Black stripe in direction of paper travel 51
White stripe in direction of paper travel 52
Poor fusing, toner offsetting 53
Repeating defect or voids on print 54
Missing characters or voids in print 55
Color misalignments 56
Unexpected colors 57
Image is skewed on the paper 58
Image is not centered on the print 58
The print is wrinkled 58
Macintosh printing problems 59
Image never prints 59
Image is rotated 90 degrees 59
Image prints in black-and-white 59
Printer isn’t in the Chooser 60
Windows printing problems 60
Image never prints 60

Service Guide
vii
Service Tests and Adjustments 61
Diagnostics mode 61
Switch scan test 63
LED head test 68
Motor and clutch tests 69
Test printing 71
Consumable count initialization 73
Consumable counter display 75
Consumable continuation counter display 76
Adjusting color density and balance 77
Printing a Test Page 77
Interpreting the Color Balance test print 77
What to look for 78
Making adjustments 78
Adjustment recovery 79
Cleaning and Maintenance 81
Service preventive maintenance procedure 81
Recommended tools 82
Periodically replaced parts 82
Cleaning 83
Cleaning the LED bar 83
Cleaning the pickup roller 83
Resetting NVRAM 85
FRU Disassembly 87
Cabinet panels 87
Top cover 87
Left-side cover 88
Right-side cover 89
Rear cover 90
Front cover 91
Face-up tray 92
Frames components 93
Right shield plate 93
Electrical chassis (card cage) 94
Electrical chassis cooling fan 96
Printer unit chassis 97
Main cooling fan 99
Top cover inner frame 100
Left/right top cover spring assembly 103
Left paper tray guide assembly 104
Right paper tray guide assembly 106

viii
Phaser 1235 Network Color Printer
Left plate assembly 108
Electronic boards 109
System controller board 109
Print engine controller board 110
Toner sensor board 111
Entrance sensor board 113
High voltage power supply 114
Low voltage power supply 116
Control panel 117
Paper feed components 118
Tray 1 feed roller and nudger roller 118
Retard pad 119
Paper-size sensing board 120
Paper-size sensing actuator 122
Main feeder assembly 123
Tray 1 no-paper/low-paper sensors 125
Paper tray lift arm roller 126
Multi-sheet bypass feeder components 127
Multi-sheet bypass feeder 127
Multi-sheet bypass feeder entrance sensor actuator 129
Paper transport components 130
Tray 1 entrance sensor actuator 130
Belt entrance sensor actuator 131
Transfer belt unit 132
Registration components 133
Registration clutch 133
Registration motor assembly 134
Registration roller assembly A and drive gear 135
Registration roller assembly B 137
Exit assembly and fuser components 139
Fuser unit 139
Fuser latching handle (left) 140
Fuser latching handle (right) 141
Fuser exit roller 142
Exit sensor assembly 144
Duplex guide assembly 146
Eject guide assembly 148
Stack full sensor 149

Service Guide
ix
Drive assembly components 151
Main motor assembly 151
Main feeder drive motor 153
Transfer belt motor assembly 154
Xerographic components 156
Shutter plate 156
Color registration sensor assembly 157
Color registration solenoid 158
LED assembly 159
Drum contact assembly 160
Toner sensor actuators 161
Duplex unit 163
Optional paper feeder components 164
Idler roller assembly 164
Inner frame 166
Feeder clutch 169
Feeder motor 171
Feeder control board 173
Paper transport roll guide 175
Feeder drive assembly 177
Paper size sensing actuator 179
Paper size sensing board 180
Lower connector 181
Upper connector 183
Tray 2/3 feed roller and nudger roller 185
FRU List 187
Using the parts list 187
Test Prints 211
Wiring Diagram 215

x
Phaser 1235 Network Color Printer
Figures
The Phaser 1235 Color Printer with lower tray feeders 1
Print engine circuit boards 5
Print engine circuit boards (cont’d) 6
Print engine sensor and switch locations 7
Print engine sensor and switch locations (cont’d) 8
Print engine motors, clutches and solenoids 9
Optional feeder motor and clutch 10
Features of the controller board 11
The control panel 12
The printer rear panel 13
Tray switch sensors and actuators 15
Door safety interlock switches 37
LED Head Test Pattern 68
Print problem caused by dirty LED lens 83
Removing the top cover 87
Removing the left-side cover 88
Removing the right-side cover 89
Removing the rear cover 90
Removing the front cover 91
Removing the face-up tray 92
Removing the right shield plate 93
Removing the electrical chassis 95
Removing the electrical chassis cooling fan 96
Disconnecting the registration motor in-line connector (HOPFF) 97
Removing the printer unit chassis 98
Removing the main cooling fan 99
Removing the top shield plate 100
Removing the harnesses from the electrical chassis 101
Removing the top cover inner frame 102
Removing the left/right top cover spring assembly 103
Removing the lower plate assembly 104
Removing the left paper tray guide assembly 105
Removing the paper tray guide assemblies 106
Removing the right paper tray guide assembly 107
Removing the left plate assembly 108
Removing the system controller board 109
Removing the print engine controller 110
Disconnecting the LED power harnesses 111
Removing the toner sensor board 112

Service Guide
xi
Removing the entrance sensor board 113
Removing the high voltage power supply 115
Removing the low voltage power supply 116
Removing the control panel 117
Removing the feed roller and nudger roller 118
Removing the retard pad 119
Removing the paper size sensing board 121
Removing the paper size sensing actuator 122
Removing the main feeder assembly 124
Removing the lower plate assembly 125
Removing the paper tray lift arm roller 126
Removing the multi-sheet bypass feeder 128
Removing the multi-sheet bypass feeder entrance sensor actuator 129
Removing the tray 1 entrance sensor actuator 130
Removing the belt entrance sensor actuator 131
Removing the transfer belt unit 132
Removing the registration clutch 133
Removing the registration motor assembly 134
Removing the registration roller assembly A and drive gear 136
Removing the registration roller assembly B 138
Removing the fuser unit 139
Fuser latching handle (left) 140
Removing the fuser latching handle (right) 141
Removing the fuser exit roller 143
Removing the exit sensor assembly 145
Removing the duplex guide assembly 147
Removing the eject guide assembly 148
Removing the LED Assembly power connector 149
Removing the stack full sensor 150
Removing the main motor assembly 152
Removing the main feeder drive motor 153
Removing the transfer belt motor assembly 155
Removing the shutter plate 156
Removing the color registration sensor assembly 157
Removing the color registration solenoid 158
Removing an LED assembly 159
Removing the drum contact assembly 160
Disconnecting the LED assembly power harness 161
Removing the toner sensor actuators 162
Removing the duplex unit 163
Removing the feeder control board cover 164
Removing the idler roller assembly 165
Removing the optional feeder inner frame bottom screws 166