Xerox 7700 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 2 1
71- 86 - 1
PHASER® 7700
COLOR PRINTER
Service Guide

User safety summary
Terms in manual: Various terms are used throughout this manual to either provide
additional information on a specific topic or to warn of possible danger that might
be present during a procedure or action. Be aware of all symbols and terms when
they are used, and always read NOTE, CAUTION and WARNING messages.
Terms on product:
Power source: For 11 VAC printers, Do not apply more than 127 volts RMS
between the supply conductors or between either supply conductor and ground.
Use only the specified power cord and connector. For 22 VAC printers, do not
apply more than 24 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.
WARNING: If the product loses the ground connection, usage of controls and
other conductive parts can cause an electrical shock.
NOTE: A NOTE may indicate an operating or maintenance
procedure, practice or condition that is necessary to
efficiently accomplish a task.
A NOTE may also provide additional information related
to a specific subject or add a comment on the results
achieved through a previous action.
CAUTION: A CAUTION indicates an operating or maintenance
procedure, practice or condition that, if not strictly
observed, could result in damage to, or destruction of,
equipment.
WARNING: A WARNING indicates an operating, or maintenance
procedure, practice or condition that, if not strictly
observed, could result in injury or loss of life.
CAUTION: A personal injury hazard exists that may not be apparent.
For example, a panel may cover the hazardous area.
ANGER: A personal injury hazard exists in the area where you see
the sign.

Power Supply and Electrical Components: Before starting any service procedure,
switch off the printer power and unplug the power cord from the wall outlet. If
you must service the printer with power applied, be aware of the potential for
electrical shock.
Do not touch any electrical component unless you are instructed to do so by a service
procedure.
Mechanical Components: Manually rotate drive assemblies to inspect and gears.
Do not try to manually rotate or manually stop the drive assemblies while any
printer motor is running
Laser Components:
WARNING:This printer generates a laser beam as part of the printing process.
The laser beam in this printer is invisible. Direct eye exposure to the
laser beam may cause eye injury or blindness.
To avoid permanent eye damage, follow these directions:
■Before starting any service procedure, switch off the printer power and unplug
the power cord from the AC wall outlet.
■Do not disassemble the Laser Scanner Assembly.
■Use caution when you are working around the Laser Scanner Assembly or
when you are performing laser related troubleshooting or repair procedures.
■Never place a mirror or a reflective tool or object in the laser beam path.
■Do not disassemble the printer in such a way that the laser beam can exit the
print engine during a print cycle.

Fuser Components:
WARNING:This printer uses heat to fuse the toner image to a sheet of paper. The
Fuser Assembly is very hot. Switch off printer power and wait at
least 3 minutes for the Fuser to cool before you attempt to service
the Fuser Assembly or adjacent components.
Safety Components: Make sure covers and panel are in place and that all interlock
switches are all functioning correctly after you have completed a printer service
call. If you bypass, or cheat, an interlock switch during a service call, use extreme
caution when working on or around the printer.
Warning Labels: Throughout the printer, warning labels are displayed on
potentially dangerous components. When you service the printer, check to make
certain that all warning labels are in place.
Most importantly, read and obey all posted warning labels.
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 main power source. 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.
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,
■Or if any liquid or foreign material is spilled into the case,
■Or if the printer is exposed to any excess moisture,
■Or if the printer is dropped or damaged,
■Or 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.

Service safety summary
For qualified service personnel only: Refer also to the preceding Users Safety
Summary.
o 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.
o 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 does
not apply more than 127 or 24 volts AC 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.
CLASS 1 LASER PRO UCT
The Phaser® 77 Color Printer is certified to comply with Laser Product
Performance Standards set by the U.S. Department of Health and Human
Services as a Class 1 Laser Product. This means that this is a class of laser product
that does not emit hazardous laser radiation; this is possible only because the
laser beam is totally enclosed during all modes of customer operation.
The laser and output of the laser scanner unit produces a beam that, if looked
into, could cause eye damage. Service procedures must be followed exactly as
written without change.
When servicing the machine or laser module, follow the procedures specified in
the manual to avoid any hazards from the laser.
Laser (FDA): Any laser label visible to service must be reproduced in the service
manual with location shown or indicated. Safe working procedures and clear
warnings concerning precautions to avoid possible exposure must also be
included.

Federal Communications Commission Compliance
This equipment has been tested and found to comply with the limits set for a
Class B digital device, as stated in Part 15 of the FCC rules. These limits are
designed to provide reasonable protection against harmful interference in a
commercial installation. This equipment generates, uses, and may radiate radio
frequency energy. If not installed and used in accordance with the instructions
provided, this equipment may cause disruptive interference to nearby radio and
television communications. Even if the equipment is installed according to the
instructions, there is no guarantee of no interference in a particular installation. If
this equipment does cause disruptive interference to nearby radio and television
reception, switch the equipment off to determine if it is the true cause of the
interference. If the equipment is the cause of the interference, the user should try
to minimize the interference by taking one or more of the following courses of
action:
NOTE: Installation of the Finisher and/or the Token Ring Interface results in an
FCC classification change to Class A.
■Either re–orient or relocate the radio/television receiving antenna.
■Increase the separation between the equipment and the radio/television
receiver.
■Connect the equipment to an AC outlet that is not on the same circuit as the
radio/television receiver.
■If the previous solutions fail to bring results, you should consult either your
equipment dealer or an experienced radio/television technician.
For more information on interference, refer to the Federal Communications
Commission’s booklet “How to Identify and Resolve Radio-TV Interference
Problems”. This booklet is available from the U.S. Government Printing Office,
Washington D.C. 2 4 2, Stock No. 4- - 345-4.

Canadian Notice
This digital apparatus does not exceed the Class B limits for radio noise
emissions from digital apparatus as described in the radio interference
regulations of the Canadian Department of Communications.
NOTE: Installation of the Finisher and/or the Token Ring Interface results in a
classification change to Class A.
Avis Canadien
Cet appareil numerique est conforme aux limites émission de bruits
radioélectriques pour les appareils de classe B stipulés das le réglement sur le
brouillage radioéletrique du Ministére des Communcations du Canada.
European Notice
This equipment was tested and is determined to be compliant with VDE
requirements for a Class B device.
Hinweis
Hiermit wird bescheinigt, dass der Babe Laserdrucker, in bereinstimmung mit
den Betimmunngen der Vfg 1 4ß 984 funkenstört ist. Der Deutschen Bundespost
wurde das Inverkehrbringen dieses Gertëes angqeigt und die Berechtigung zur
berprufung der Serie auf Einhaltung der Bestimmungen eingeräumt.

ES Precautions
Some semiconductor devices are easily damaged from static electricity. These
components are Electrostatically Sensitive Devices (ESDs); examples include
integrated circuits (ICs), Large-Scale Integrated circuits (LSIs), some field-effect
transistors and semiconductor chip components. The following techniques reduce
the occurrence of component damage caused by static electricity:
CAUTION:Be sure the power is off to the chassis or circuit board, and observe all
other safety precautions.
■Immediately before handling any semiconductor components assemblies,
drain the electrostatic charge from your body by touching a known earth
ground. Alternatively, wear a discharging wrist strap device. (Be sure to
remove the strap before applying power to the unit under test to avoid
potential shock.)
■After removing an ESD-equipped assembly, place it on a conductive surface
such as aluminum foil or the static bag to prevent accumulation of an
electrostatic charge.
■Do not use freon-propelled chemicals. These can generate electrical charges
sufficient to damage ESDs.
■Do not remove a replacement ESD from its protective package until you are
ready to install it. Most replacement ESDs are packaged with leads that are
electrically shorted together by conductive foam, aluminum foil or other
conductive materials.
■Immediately before removing the protective material from the leads of a
replacement ESD, touch the protective material to the chassis or circuit
assembly into which the device is to be installed.
■Minimize body motions when handling unpackaged replacement ESDs.
Motion such as your clothes brushing together, or lifting a foot from a carpeted
floor can generate enough static electricity to damage an ESD.
■Handle ICs and EPROMs carefully to avoid bending a pin.
■Pay attention to the direction of parts when mounting or inserting them on a
PCB.

Service Quick Reference Guide - Table of Contents i
Contents
General Information 1-1
Phaser 7700 Prin er overview ..................................................................................1-2
Prin er RAM and prin er capabili ies ................................................................1-4
CRC life coun er behavior ................................................................................1-5
Prin Engine Con rol Boards and Power Supplies ............................................1-6
Auxiliary Feeder Con rol Board .......................................................................1-9
Prin Engine Sensors and Swi ches .................................................................1-10
Auxiliary Feeders Sensors and Swi ches ........................................................1-12
Prin Engine Solenoids, Ac ua ors and Clu ches ...........................................1-14
Image Processor Board ...................................................................................1-16
Assemblies of he Prin Engine .......................................................................1-17
Fron Panel Descrip ion .........................................................................................1-21
Rear panel ..............................................................................................................1-23
Specifica ions .........................................................................................................1-24
Suppor ed paper weigh s, page sizes and prin area .......................................1-27
Diagnostics, Error Codes and Messages 3-31
Error messages .......................................................................................................3-31
Troubleshoo ing Error Codes .................................................................................3-31
Sys em Boo Sequence ....................................................................................3-32
Power On Self Tes (POST) ............................................................................3-32
POST Faul s ....................................................................................................3-33
Faul Repor ing Devices .................................................................................3-33
LED Blink Pa erns .........................................................................................3-33
POST Diagnos ics Tes Descrip ions ..............................................................3-34
Service Diagnos ics .........................................................................................3-35
Service Diagnos ics Tes Menu Func ions ......................................................3-36
Error Codes and Messages Troubleshoo ing .........................................................3-47
Vol age Measuremen s ...........................................................................................3-47
Troubleshooting 3-85
Troubleshoo ing Power Supplies and In erlocks ...................................................3-87
Troubleshoo ing AC Power ............................................................................3-87
Troubleshoo ing he Low-vol age Power Supplies .........................................3-88
Troubleshoo ing he 3.3 VDC and 5 VDC LVPS ...........................................3-88