2009 Xerox Phaser 6128MFP Service Manual (P/N 701P49279)

• Exact coverage: Covers the 110 V Phaser 6128MFP (product code RCX) and 220 V Phaser 6128MFPV (product code RDA); the serial table identifies them as 6128MFP_N and 6128MFPV_N, with the documented range 050501 through 500500 for both versions. This is a 606-page PDF, Xerox Part# 701P49279, First Printing March 2009.
• Print-engine and MFP theory: Explains the single-pass, tandem four-drum CMYK process from charging and laser exposure through development, transfer, cleaning, and fusing, plus the scanner, ADF, copier image path, and G3 fax system.
• Fault isolation: Works from Error History reports and Chain Link codes into repair procedures for jams, fuser and toner faults, CTD and imaging-unit errors, motors, firmware and memory, email/SMB scanning, copier/scanner faults, and fax communication failures.
• Service diagnostics: Details IIT board and I/O tests for the fax, ADF, and scanner; IOT tests for sensors, motors, solenoids, erase lamps, NVM data, life counters, and engine electronics; and test-print methods that separate MCU faults from Image Processor Board faults.
• Image-quality work: Provides symptom-based repair charts for light, blank, black, banded, streaked, ghosted, skewed, unfused, and misregistered output. Contamination Check, Pitch Chart, alignment, gradation, ghost, and imaging-unit refresh prints support component-level diagnosis.
• Adjustments and replacement: Covers automatic and manual color registration, scanner calibration after replacement, fuser-counter reset, print-meter and NVRAM initialization, print/fax/scanner parameter settings, and boot-controller, main-controller, and MPC firmware updates.
• Disassembly, parts, and wiring: Documents removal and replacement paths for the imaging unit, fuser, feed and registration hardware, transfer belt, laser unit, drive assemblies, LVPS/HVPS, control boards, scanner, and ADF. The electrical section adds a system-connections drawing, four plug/jack locator maps, and 11 dedicated wiring sheets.

Xerox Service Scope and System Theory

Xerox identifies this manual as intended for authorized Xerox service technicians and service partners. It assumes qualified service personnel, and the technical-support section states that Xerox certification for this product is required. It is a factory repair reference rather than an operator-level maintenance guide.

The theory chapter ties the mechanical and electrical systems together. Along with the Print Process Block Diagram, it covers media registration, color/monochrome drive switching, laser light-quantity control, potential and toner-density control, CTD-based color registration, and fuser temperature control. Scanner coverage explains CCD image conversion, AGC/AOC compensation, platen scanning, ADF transport, and image-data flow. Fax material extends through the five-phase G3 Protocol Monitor sequence and ITU-T recommendations.

Diagnostic and Repair Depth

The troubleshooting sequence connects control-panel codes and stored error history to diagnostic tests, wiring test points, parts identification, FRU removal, and final operational checks. Print-quality tables relate visible defects to the laser unit, imaging unit, transfer belt, fuser, and media path. The Pitch Chart is especially useful for matching repeating marks to specific rollers and xerographic components.

The disassembly chapter is supported by separate removal and replacement flow diagrams. Fifteen illustrated parts-list groups cover the feeder, xerographics, dispenser, transfer/fuser, drive, covers, frame, electrical assemblies, harnesses, scanner, and ADF. Parts without an individual orderable number are supplied with their parent assembly. The maintenance chapter also provides Xerox's RIP (Repair, Inspect, and Prevent) procedure.

Diagrams and Parts Identification

Representative technical views include the Print Process Block Diagram, Scanner Image Data Flow, G3 Protocol Monitor flow chart, Media Feed wiring diagram, HVPS wiring diagram, and Scanner/Imaging wiring diagram. The plug/jack tables cross-reference connectors to map coordinates and parts-list callouts, while the illustrated catalog supplies orderable component and service-kit numbers.

The parts data distinguishes the 115 V fuser (675K65653) from the 220 V fuser (675K65663) and separates US/EU from DMO toner-cartridge versions. Specification tables retain the machine-level reference data: 128 MB onboard memory with a 256 MB DDR2 expansion DIMM for 384 MB maximum, 12-ppm color and 16-ppm monochrome printing, USB 2.0 and 10/100 Base-TX Ethernet, 600-dpi network scanning, copy/fax specifications, supported media, and electrical data for both voltage families.

Service Cautions

The manual flags repair traps that are easy to miss. Light exposure can quickly degrade the imaging unit and cause early failure, while the ferrite core on the IIT subassembly ribbon cable is extremely fragile during scanner teardown. It also identifies machine-screw and tapping-screw locations because misalignment or overtightening can damage previously tapped plastic threads.

Internal service can expose hazardous voltages, a hot fuser, enclosed laser components, and ESD-sensitive electronics. Some live diagnostic tests require an interlock override; technicians should follow the manual's power-isolation, cooling, laser, and ESD precautions throughout the repair.