About This Manual; Organization; How To Use This Documentation; Symbology - Xerox Phaser 790 Service Manual

About this Manual

This Service Manual is part of the multinational documentation system for the Phaser 790
Printer and DC 2006 Copier./Printer The Service Documentation is used in order to diagnose
machine malfunctions, adjust components and has information which is used to maintain the
product in superior operating condition. It is the controlling publication for a service call. Infor-
mation on its use is found in the Introduction of the Service Documentation.
This manual contains information that applies to NASG and ESG copiers.
Service Manual Revision
The Service Manual will be updated as the machine changes or as problem areas are identi-
fied.

Organization

This Service Manual is divided into nine sections. The titles of the sections and a description of
the information contained in each section are contained in the following paragraphs:
Section 1 Service Call Procedures
This section contains procedures that determine what actions are to be taken during a service
call on the machine and in what sequence they are to be completed. This is the entry level for
all service calls.
Section 2 Status Indicator RAPs
This section contains the diagnostic aids for troubleshooting the Fault Code and non-Fault
Code related faults (with the exception of copy quality problems).
Section 3 Image Quality
This section contains the diagnostic aids for troubleshooting any copy quality problems, as well
as copy quality specifications and copy defect samples.
Section 4 Repairs/Adjustments
This section contains all the Adjustments and Repair procedures.
Repairs
Repairs include procedures for removal and replacement of parts which have the following
special conditions:
When removal or replacement cannot be determined from the exploded view of the
Parts List.
When there is a cleaning or a lubricating activity associated with the procedure.
When the part requires an adjustment after replacement.
When a special tool is required for removal or replacement.
Use the repair procedures for the correct order of removal and replacement, for warnings, cau-
tions, and notes.
Initial Issue
Phaser 790/DocuColor 2006
Adjustments
Adjustments include procedures for adjusting the parts that must be within specification for the
correct operation of the system.
Use the adjustment procedures for the correct sequence of operation for specifications, warn-
ings, cautions and notes.
Section 5: Parts Lists
This section contains the Printer/Copier Parts List.
Section 6: General Procedures/Information
This section contains General Procedures, Diagnostic Programs, and Copier Information.
Section 7: Wiring Data
This section contains drawings, lists of plug/jack locations, and diagrams of the power distribu-
tion wire networks in the machine. Individual wire networks are shown in the Circuit Diagrams
contained in Section 2. This section also contains the Block Schematic Diagrams.

How to Use this Documentation

The Service Call Procedures in Section 1 describe the sequence of activities used during the
service call. The call must be entered using these procedures.
Use of the Circuit Diagrams
Circuit Diagrams (CDs) are included in Sections 2 (Status Indicator RAPs) and 3 (Image Qual-
ity RAPs) of the Service Manual. All wirenets, with the exception of power distribution wirenets,
are shown on the CDs. Power distribution wirenets are shown in Section 7 (Wiring Data) of the
Service Manual. The power distribution wirenets on the CDs will end at the terminal board for
the power being distributed. Find the wirenet for that power and locate the terminal board on
the wirenet. Use the wirenet to troubleshoot any power distribution wiring not shown on the
CD.
Use of the Block Schematic Diagrams
Block Schematic Diagrams (BSDs) are included in Section 7 (Wiring Data) of the Service Man-
ual. The BSDs show the functional relationship of the electrical circuitry to any mechanical, or
non-mechanical, inputs or outputs throughout the machine. Inputs and outputs such as motor
drive, mechanical linkages, operator actions, and air flow are shown. The BSDs will provide an
overall view of how the entire subsystem, such as ADF, works.
It should be noted that the BSDs no longer contain an Input Power Block referring to Chain 1. It
will be necessary to refer to the Wirenets in order to trace a wire back to its source.

Symbology

The following reference symbols are used throughout the documentation.
10/00
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Introduction