Tektronix Phaser 840 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: November 1999
071-0388-01
PHASER® 840aND 850
COLOR PRINTERS
Service Manual

User safety summary
Terms in manual
CAUTION Conditions that can result in damage to the product.
WARNING Conditions that can result in personal injury or loss of life.
Power source:
For 110 VAC printers, Do not apply more than 130 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 250 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.
WARNING Turning the power off using the On/Off switch does not de-
energize the printer. You must remove the power cord to
disconnect the printer from the mains. Keep the power cord
accessible for removal in case of an emergency.
Safety instructions:
Read all installation instructions carefully before you plug the
product into a power source.
Terms on product
CAUTION A personal injury hazard exists that may not be apparent.
For example, a panel may cover the hazardous area. Also
applies to a hazard to property including the product itself.
DANGER Apersonal 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 250 volts rms 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
Phaser 840 printer overview 2
Phaser 850 printer overview 4
Solid inks 5
About RAM upgrades 5
Memory considerations 6
Print engine assemblies 8
Combination sensors and their meanings 16
Media tray type sensing 16
The main board 17
Front panel 19
Rear panel 20
Phaser 840 and Phaser 850 printer differences 23
Specifications 24
Regulatory specifications 28
Error Codes and Messages 29
Rear panel LED error codes 29
Error messages 32
Troubleshooting 55
Front panel shortcuts 55
Access fault history 55
Set front panel language 55
Access service menu 55
Fast time to ready 55
Network Event Logs (Phaser 850) 56
System power-up sequence 57
No lights, no sound on power-up 59
Verifying main board CPU operation 59
Verifying print engine operation by printing its startup page 59
Verifying power supply operation 60
Measuring power supply voltages 60
Inspecting the power supply fuses 61
Testing for shorted drivers 62
Testing for a shorted motor 63
Testing motor and solenoid resistances 63
Testing the cap/wipe/purge vacuum system 63\

vi Phaser 840 and 850 Color Printers
Media jams and the paper path 64
Media-based problems 64
Paper-pick errors 64
Print transfer jams 65
Checking the process motor and drive train 66
Media skews passing through the paper path 66
Printing and print quality problems 67
Not printing 67
Streaks or lines across the print 67
Missing ink or light colored ink band running length of print 68
Color is uneven 68
Streaks or lines down the print 69
Scratches parallel to the long axis of printing, particularly with film 70
Printing too light or too dark 70
White portion of print is colored 71
Fuzzy text 72
Variation of density on second side of print 72
Ghost of first side image on second side of print 72
Poor primary color fills 73
Ghosting 74
Poor small text resolution 74
Vertical line appear wavy 75
Oil streaks on print 75
Incomplete image transfer to paper 76
Ink smears on first side of duplex print 77
Repeating print defects on print 77
Banding parallel to long edge of print 78
Wrinkling 78
Image is offset or cut off 79
Oil streaks on top of print 79
Poor ink adhesion, poor image durability 79
Evaluating the printhead and cap/wipe/purge system 80
Troubleshooting following cap/wipe/purge installation 85
Macintosh printing problems 88
Image never prints 88
Image is rotated 90 degrees 88
Image prints in black-and-white 88
Printer isn’t in the Chooser 89
Windows printing problems 89
Image never prints 89

Service Guide
vii
Adjustments 91
Fast time to ready 91
Bypass mode (manufacturing mode) 91
Cool down mode 91
Bypassing a “short menu” 92
Printing service test prints 92
Printing the Configuration Page 92
Hidden service menu 93
Selecting Duplex (2-sided) Oil Chase 94
Selecting Envelope Oil Chase 94
Center Image 94
Locking the printhead 95
Adjustments 96
Process belt tension adjustment 96
Exit roller drive belt tension adjustment 97
Y-axis belts tension adjustment (Phaser 840 printer) 98
Y-axis belts tension adjustment (Phaser 850 printer) 100
Printhead-to-drum spacing adjustment (Phaser 840 printer) 102
X-axis scale adjustment 105
Cap/wipe/purge assembly belt adjustments 106
Drum position encoder gap 108
Transfix roller pressure spring adjustment 110
Vacuum check 112
Cleaning and Maintenance 115
Cleaning 116
Cleaning Page (Phaser 840 printer only) 117
Vacuum 117
Drum temperature sensor 117
Maintenance 118
Maintenance roller 118
Waste tray 118
Lubrication 119
Inspection 120
Resetting NVRAM 121
Resetting NVRAM 121

viii Phaser 840 and 850 Color Printers
Key FRU Removal and Replacement 125
Main board and its components 126
Power supply 128
Power control board 129
Upper feed roller assembly 130
Paper/drum heater 132
Drum/transfix assembly 133
Drum position sensor assembly (Phaser 840 printer) 138
Drum position sensor assembly (Phaser 850) 140
Printhead 142
X-axis motor and drive assembly 145
Y-axis belt drive assembly (Phaser 840 printer) 146
Y-axis belt drive assembly (Phaser 850 printer) 147
Cap/wipe/purge assembly (Phaser 840 printer) 148
Cap/wipe/purge assembly (Phaser 850 printer) 150
FRU List 153
High-capacity Paper Tray Assembly 170
Service tools 172
Supplies and accessories 173
Test Prints 177
Wiring Diagrams 191

Service Guide
ix
Figures
The Phaser 850 printer (shown with optional High-capacity Paper Tray Assembly) 1
Internal features of the print engine 8
Circuit boards of the print engine (right front view) 9
Circuit boards of the print engine (left-rear view) 10
The printer’s I
2
C bus 11
Printhead maintenance system of the print engine 12
Sensors and switches on the right side of the print engine 13
Sensors and switches on the left side of the printer 14
Solenoids and clutches on the print engine 15
Features of the Phaser 840 printer main board 18
Features of the Phaser 850 printer main board 18
Printer front panel 19
Phaser 840 printer rear panel 22
Phaser 850 printer rear panel 22
Attaching the service load connector to J250 62
Faceplate showing blade wipe with no drops, smudges or streaks 80
Faceplate showing streaks and smudges from a poor wipe 81
Connecting the vacuum gauge to the printer 82
Maintenance tray showing good purge 84
Damaged printhead data cable 86
Inadvertently disconnected thermistor cable connector 87
Setting process belt tension 96
Setting exit roller drive belt tension 97
Setting the Y-axis belt tension 99
Setting the Y-axis belt tension 101
Attaching the digital gap indicator 103
Spacing the printhead to the drum 104
Adjusting the x-axis scale adjustment 105
Aligning (timing) the cap/wipe/purge assembly drive belts 107
Setting the drum position encoder gap 109
Adjusting the transfix roller pressure springs 111
Connecting the vacuum gauge to the printer 112
Lubricating the transfix cam 119
Resetting print engine NVRAM menu item 122
Clearing PostScript NVRAM menu item 123
Removing the Phaser 840 printer main board 126
Removing the Phaser 850 printer main board 127
Removing the power supply 128
Removing the power control board 129

x Phaser 840 and 850 Color Printers
Remove the upper feed roller assembly (left side) 130
Removing the upper feed roller assembly (front) 131
Removing the paper/drum heater 132
Removing the drum transfix assembly (left side) 134
Removing the drum/transfix assembly (right side) 136
Marking the drum home flag sensor alignment 138
Removing the drum position sensor assembly (Phaser 840 printer) 139
Marking the shaft for drum home alignment 140
Removing the drum position sensor assembly (Phaser 850 printer) 141
Plugging the reservoir holes 142
Removing the printhead 143
Removing the x-axis motor and drive assembly 145
Removing the Y-axis belt drive assembly (Phaser 840 printer) 146
Removing the Y-axis belt drive assembly (Phaser 850 printer) 147
Removing the cap/wipe/purge assembly (Phaser 840 printer) 149
Removing the lower cap/wipe/purge retainer clip 150
Removing the lower cap/wipe/purge retainer clip 151
Removing the cap/wipe/purge assembly (Phaser 850 printer) 152
Cabinet FRUs 155
Imaging FRUs 157
Paper path FRUs 159
Motor and fan FRUs 161
Circuit board FRUs 163
Solenoid and clutch FRUs 165
Gear and belt FRUs 167
Sensor and flag FRUs 169
High-capacity Paper Tray 171
Print engine wiring diagram 191
Wire routing on the right side of the printer near right I/O board 192
Wire dressing above the x-axis drive 193
Vacuum hose dressing 194
Routing wiring on the left side of the printer 195
Wire dressing behind the printhead 196

Service Guide
xi
Tables
Installed RAM and printer capabilities 6
Tray switch sensor combinations 16
Rear panel DIP switch settings 21
Summary of differences between Phaser 840 and Phaser 850 23
Physical dimensions 24
Printer installation clearances 24
Functional specifications 25
Electrical specifications 26
Environmental specifications 27
Main board power-up self-test error codes 29
Front panel and fault history log error codes and messages 32
Motor and solenoid resistances 63
Hidden Service Menu 93
Cabinet FRUs 154
Imaging FRUs 156
Paper path FRUs 158
Motor and fan FRUs 160
Circuit board FRUs 162
Solenoid and clutch FRUs 164
Gear and belt FRUs 166
Sensor and flag FRUs 168
High-capacity Paper Tray FRUs 170
Service tools 172
Supplies and accessories 173