2003 Xerox K-C2 Service Manual (P/N 001874MIU)

• Model coverage: Covers Model K-C2 machine codes B121, B122, and B123. B121 is the one-tray, non-duplex version; B122 is the two-tray, non-duplex version; and B123 is the two-tray model with the built-in duplex unit.
• Installation coverage: Documents the B406 platen cover, B616 ADF, B617 ARDF, B384/B385 paper tray units, heaters, and key counter. MFP coverage includes the B658 controller box, B620 fax, B622 printer/scanner, B681 PostScript 3, and the B621 one-bin tray for applicable B122/B123 configurations, plus IEEE 1284/1394, wireless LAN, and Bluetooth interfaces.
• Major repair work: Provides removal, replacement, and adjustment coverage for the scanner and optics, laser unit, PCU and OPC drum, developer and toner-control system, paper feed and registration, image transfer, fusing unit, B123 duplex system, BICU, power supplies, motors, fans, and gearbox.
• Diagnostic material: Includes SC-code descriptions, connector-referenced sensor and switch fault tables, fuse conditions, BICU LED information, input/output checks, jam histories, SMC print functions, ID-sensor analysis, APS displays, and service test patterns.
• Service Program support: Separates SP-mode tables for the basic machine and the MFP configuration with the optional controller box. Coverage includes registration, magnification, and standard-white density calibration, PM-counter reset, memory clear, serial-number entry, NVRAM upload/download, and firmware updating for both machine types.
• Document details: A 321-page PDF, dated December 1, 2003, with labeled component-removal views, system diagrams, service tables, operating theory, regional paper-size data, machine-configuration charts, and optional-equipment specifications.

Installation and Maintenance Procedures

The opening chapter covers site environment, machine leveling, service clearance, grounded power, accessory checks, and option mounting. Initial setup includes developer loading, TD-sensor initialization through SP mode, language selection, and print-registration checks.

MFP conversion is broken down by controller box, RAM and SD-card hardware, USB board, PostScript card, fax control unit, panels and keys, and the required settings. One expansion slot is available for the IEEE 1284, IEEE 1394, wireless LAN, or Bluetooth interface, so only one of those options can be installed at a time.

Preventive-maintenance tables are organized around the optics, drum area, paper-feed system, fusing unit, ADF/ARDF, and optional paper-tray units. They identify the required cleaning, inspection, replacement, and lubrication work and include the PM-counter reset procedure. Regional setup information covers original-size sensor positioning, including the China-market 8K/16K arrangement.

Electrical isolation matters on this machine. Some assemblies remain energized with the main switch off, while the fusing and laser sections carry component-specific heat and radiation hazards. The laser subsystem may be replaced in the field by a qualified technician, but the optical housing and laser chassis are not field-repair items.

Accessory installation is included in this PDF. The separate B621 one-bin-tray and B616/B617 ADF/ARDF repair chapters referenced in the table of contents, however, are not present in this 321-page file.

Component Adjustments and Technical Data

The repair chapters go well beyond cover removal. They include scanner-belt alignment with positioning pins, lens-block and exposure-lamp service, laser-unit alignment using the Trimming Area test pattern, PCU disassembly, OPC drum and charge-roller repair, cleaning-blade and developer service, paper-feed clutch and sensor replacement, fuser roller/lamp/thermistor work, nip-band adjustment, duplex motor and control-board repair, BICU/NVRAM handling, and gearbox removal. A numbered gearbox layout shows the correct installation order if the gear train comes apart during repair.

The special-tools table identifies A0069104 scanner positioning pins, A2929500 Test Chart S5S, A0299387 FLUKE 87 digital multimeter, A2309352 flash-memory card, G0219350 loop-back connector, and B6455010 SD-card assembly.

Several repair traps are called out clearly. Disturbing the paint-locked lens-block or LD-unit screws can upset the factory alignment, and handling the lens block by its PCB or lens assembly can shift it out of position. The PCU cleaning-blade section specifies applying toner to the new blade edge to prevent damage to the blade and OPC drum. When replacing the BICU, the original NVRAM must be transferred because it carries machine-specific data.

Beyond the fault-code tables, the manual explains how the engine works. Particularly useful references include the Component Layout, Paper Path, Drive Layout, BICU/SBU Block Diagram, Copy Process Overview, and Image Processing Path. Detailed sections also cover scanner drive and APS detection, image processing, laser auto-power control, toner-density control, transfer timing, fusing control, duplex operation, and energy-saver sequencing.

Electrical troubleshooting is functional rather than harness-by-harness. Connector references, sensor and switch symptom tables, fuse charts, board block diagrams, and SP input/output checks are included, but this is not a separate point-to-point wiring-diagram manual. Technical tables cover regional original and paper-size recognition, machine configurations, optional equipment, adjustment data, and supported media.