Xerox Phaser 840/850/860 Service Manual + 8200 Addendum, 2002 (P/N 071-0723-00)

Xerox's April 2002 Phaser 840/850/860 Network Color Printer Service Manual, P/N 071-0723-00, includes the Phaser 8200 Color Printer Addendum.

Searchable PDF and Wiring Diagram Detail

Search, bookmarks, and diagram detail: Searchable PDF text and embedded bookmarks provide access to the main chapters, addendum, and troubleshooting appendix. Small connector numbers in the landscape print-engine wiring diagram are best read with zoom.

One printable English PDF contains 287 pages: 16 pages of covers and front matter, 240 main-manual pages, a 2-page Phaser 8200 addendum, a 28-page troubleshooting appendix, and one back cover. All are included in the total.

Print-Engine Repair and Fault Diagnosis

The following selected coverage highlights major service areas. Further topics include network event logs and Macintosh and Windows printing problems.

• Imaging and paper-path repair: Step-by-step removal and replacement procedures for the printhead, drum/transfix assembly, paper/drum heater, upper feed roller, X-axis drive, Y-axis drive, and cap/wipe/purge assembly.

• Power and control electronics: Main-board, power-control-board, and power-supply replacement, plus checks for shorted drivers, motors, and solenoids.

• Fault isolation: BIST, POST, rear-panel LED codes, fault-history messages, customer-mode power-up sequences, and system faults from the 2,000 I/O-board group through the 31,000 motor-fault group.

• Paper handling and print quality: Repair Analysis Procedures for paper-pick and transfer jams, media skew, process-drive faults, weak or missing jets, ghosting, wrinkling, banding, and repeating defects.

• Factory adjustments: Service test prints, process and exit belt tension, Y-axis belt tension, X-axis scale, cap/wipe/purge belt timing, drum-position encoder gap, transfix pressure, and NVRAM resets.

• Parts and maintenance: Illustrated FRU identification, model-dependent part numbers, service-tool listings, electrical test specifications, cleaning, lubrication, and component inspection information.

This manual is written for qualified service personnel; Xerox recommends Phaser 840/850/860 printer service training.

Model Differences and Phaser 8200 Coverage

Configuration information distinguishes Phaser 840N/DP/DX/GP/DPF, 850N/DP/DPF/DX, and 860B/N/DP/DPF/DX builds. It compares their main-board, memory, networking, hard-drive, duplex, paper-tray, printhead-mount, Y-axis, and cap/wipe/purge differences.

The Phaser 840 has a printhead-to-drum spacing adjustment. The Phaser 850 and 860 printheads are factory adjusted; the manual calls for replacement when a printhead is known to be out of adjustment.

The Phaser 8200 addendum states that Phaser 860 characteristics apply unless an exception is listed. It documents the revised PowerPC platform, unique ColorStix 8200 ink shapes and formulation, reorganized Service Tools menu, changed internal pages, and 8200DX memory configuration. Most Phaser 8200 repair coverage therefore comes from the Phaser 860 sections in the main manual.

Companion material: Key FRU procedures are illustrated here, while printer theory of operation, more detailed removal/replacement procedures, configuration-page explanations, and additional operation-verification material are assigned to the separate Color Printer Service & Support Resources CD-ROM.

Diagnostics and Printhead Evaluation

The Phaser 860 section explains front-panel Auto Diagnostics, Customer Accessible Diagnostic Mode, and Service Diagnostics Mode. Tests cover temperatures, supply voltages, paper-path status and timing, Y-axis geometry and belt slip, cap-axis geometry and drive, cap vacuum, drum-maintenance performance, process-motor tracking, and transfix loading.

Comparable Phaser 840/850 checks may require the PC diagnostic software, serial cables, service adapter, or service plug identified in the tool list. The test-print menu lists 23 selections, with model-specific manufacturing checks, supporting X-axis, head-to-drum gap, color-fill, drum-seal, skew, and banding evaluation.

Printhead evaluation links the Weak/Missing Jet test print with faceplate, wiper, gasket, vacuum, and decay checks. These references help distinguish printhead faults from maintenance-system problems before a replacement head is selected.

Wiring, Assembly Views, and Service Tools

Named visual references include The printer's I2C bus, Printhead maintenance system of the print engine, right- and left-side sensor maps, the Print engine wiring diagram, cap/wipe/purge belt-timing illustrations, and drum/transfix removal views.

The wiring diagram maps the boards, sensors, clutches, solenoids, motors, heaters, and High-Capacity Paper Tray connections. Wiring-fold illustrations show harness and vacuum-hose routing. FRU exploded views cover imaging, paper path, motors and fans, circuit boards, solenoids and clutches, gears and belts, sensors and flags, and the High-Capacity Paper Tray.

Special tools are identified by part number: Y-axis encoder spacer 003-1489-00, Phaser 840 belt tensioner 003-1500-00, Phaser 840/850 service plug 003-1707-00, Phaser 840 head-to-drum gap clip 650-4197-00, and Phaser 840/850 vacuum gauge assembly 650-4051-00.

Printhead Positioning and Repair Cautions

Because NVRAM retains the last known printhead and cap/wipe/purge positions, moving these assemblies while power is off can cause a collision at the next startup. Disturbing drum-encoder indexing can move stripper-finger or rapid-release-guide contact marks into the printable area; incorrect harness or vacuum-hose routing can leave wiring pinched or exposed to moving parts.

AC line voltage can remain present at the heaters while the printer is switched off but still plugged in. Follow the manual's electrical-isolation instructions and qualified-service restrictions before internal repair work.

Examples of Motor Resistance Test Data

For the Phaser 840/850/860, the X-axis motor table specifies approximately 12.5 ohms per phase, measured red-to-yellow and blue-to-orange with the motor disconnected from the printer.

Process-motor resistance is approximately 2.9 ohms ±15% on the Phaser 840 and 4.3 ohms ±15% on the Phaser 850/860. The manual notes that brush/commutator contact makes these measurements variable.