2007 Xerox Phaser 8400/8500/8550/8560 Color Printer Service Manual (P/N 701P27910)

Xerox service manual 701P27910 is the January 2007 edition for Phaser 8400, 8500, 8550 and 8560 color printers. It covers base, network, duplex and DX configurations, with tables comparing memory, font sets, interfaces and installed options.

• Fault diagnosis: BIST, POST and PEST reporting, fault-code troubleshooting, jam-code interpretation, and service diagnostics for sensors, heaters, motors and clutches.

• Printhead and ink system: Printhead and purge-pump removal, ink-loader service, wiper alignment, weak-jet troubleshooting and model-specific Jet Substitution Mode.

• Drum and transfix service: Drum assembly, stripper carriage and transfix load module removal, plus drum-maintenance camshaft timing and process-drive homing.

• Paper transport: Pick assemblies, duplex rollers, media drive and paper preheater procedures, with paper-path checks and tray-specific jam diagnosis.

• Electronics: Wave amplifier, I/O board and drum heater relay board replacement, NVRAM reset and replacement, power-supply checks, and motor/solenoid resistance tables.

• Service references: Wiring diagrams, exploded parts views, service-test print interpretation, and cleaning and maintenance procedures for the print engine.

This manual is intended for authorized Xerox service technicians and service partners qualified to perform internal printer service.

Fault Isolation and Print-Quality Diagnosis

Fault tables link reported errors to checks for memory, sensors, motor drives and thermal systems. PEST tables distinguish the 8400 from later models where code assignments differ, helping technicians select the correct component checks before ordering parts.

Print-quality troubleshooting covers light stripes, smears, ghosting, uneven color, incomplete image transfer and repeating defects. Weak/Missing Jet, Reverse Text and solid-fill test prints help distinguish printhead, drum and transfix problems.

Print Engine Operation, Alignment and Replacement

The operating-theory chapter follows ink delivery, drum preparation and transfixing through the drive and electronics systems. Repair procedures include assembly removal and replacement notes wherever reassembly requires additional attention.

Mechanical alignment: Wiper alignment, head-tilt homing and drum-maintenance camshaft timing are documented with position illustrations. The timing procedure warns that overtightened process-drive screws can permanently damage the chassis mounting bosses.

Jet substitution and adjustment limits: On the 8400, jet substitution is a temporary measure with a printing-speed penalty. The later models have different operating limits and printhead-replacement criteria. The 8400 Head-to-Drum Gap test checks installation; the gap itself is not adjustable.

Electronics Service, Wiring and Reference Tables

Electrical troubleshooting separates heater-supply problems from DC power faults, with printhead thermistor readings, voltage monitoring and resistance checks.

Module replacement: The electronics module is serviced as a complete assembly. Its replacement procedure covers transferring the configuration card, NVRAM, RAM and optional hard drive; component-level repair of its internal boards is outside that procedure.

Printhead and wave amplifier replacement notes address flex-cable routing and seating. Incorrect cable insertion can damage the wave amplifier.

Wiring diagrams: The Main Wiring Diagram traces board-to-board connections. Right-Side, Left-Side, Inside Front and Inside Top - Printhead wiring diagrams locate harnesses and connectors, with PEST fault references alongside relevant connections.

The Jam Code Definition Table, Media Margin Specification Table and Paper Weight Equivalence Table support fault interpretation and media selection. Network and USB port tests are also covered; serial back-channel tracing specifies adapter 600T80374.

Internal high-voltage components require the manual's grounding and power-isolation precautions during service.

A Preview of Drum Temperature and Motor Test Data

These examples are a small selection of the thermal and electrical reference values in the manual.

Drum imaging: The drum surface is heated to approximately 60°C (140°F) for imaging, with temperature monitored by the drum-temperature sensor.

Disconnected-motor checks: The resistance table lists the X-axis motor at approximately 12.5 ohms per phase and the media-path drive motor at 1.5 ohms ±20%. These values apply to winding checks with the motors disconnected from the printer.

Searchable Text, Bookmarks and PDF Contents

Navigation and wiring detail: Searchable text and embedded chapter and section bookmarks support navigation through the manual. Small connector and circuit labels in the main wiring diagrams are best read with zoom.

One printable, English-language 376-page PDF. The total includes 353 pages of technical chapters, reference material and index, 16 preliminary pages, two covers, four blank pages and one notes page; all are already included in the page count.