Lexmark C930/C935 2007 Color Laser Printer Service Manual (P/N 12G9765)

Lexmark service manual, edition May 23, 2007, P/N 12G9765, for the C930 (5057-030) and C935 (5057-230) network models. Service information applies to both models unless a procedure states otherwise.

PDF Search, Bookmarks, and Wiring Sheets

Text access and diagram detail: Service text is searchable, and embedded PDF bookmarks cover chapters, repair procedures, and parts groups. Some notice text and labels within illustrations are outside the text search. Small wiring labels require zooming, particularly on the oversized printer schematic.

ZIP download containing one printable 568-page PDF, including the cover and copyright page, other front matter, indexes, 12 blank pages, and both wiring-diagram sheets.

Print Engine, Tray Modules, and Service Diagnostics

These selected service topics outline the manual’s coverage rather than reproduce its full contents. Other included material covers paper-size switch-state tables and the power-on reset sequence.

• Tray modules: Dedicated theory, diagnostics, repair procedures, connector views, wiring, and parts coverage for the tandem tray module (TTM), 1TM, and 3TM.

• Media transport and imaging: MPF, tray, registration, second-transfer, fuser, duplex, bridge, and output paths, plus printhead scanning and the xerographic cycle.

• Fault isolation: Jam-code service checks, controller and drive faults, printhead and fuser errors, RFID and ATC faults, tray sensing, communications, and image-quality troubleshooting.

• Service tests and setup: Individual motor and sensor tests, feed and print tests, event logs, failure clears, developer-unit reset, ATC sensor setup, and RegCon color registration.

• FRU repair: Step-by-step removal and replacement procedures for mechanical, xerographic, drive, electrical, duplex, controller, and modular-tray assemblies.

• Wiring and parts identification: Connector-location views, printer and tray-module wiring diagrams, and an illustrated FRU catalog organized into 53 assembly groups.

Lexmark prepared this manual for professional service personnel.

Media Paths and Print-Engine Operation

Basic and configured-machine drawings identify the trays, MPF, duplex, bridge unit, and optional finisher. Separate module sections explain feed and lift motors, media-level and media-out sensors, feed-out sensors, size switches, interlocks, and controller cards. The 2000-sheet TTM also has a dedicated tray-4 transport drive.

This configuration split helps match a tray-specific feed, sensing, or communications fault to the correct module before repair parts are selected.

The xerographic section follows charge-roll HVPS operation, laser exposure, development, transfer to the belt, second transfer to the sheet, drum cleaning, discharge, and fusing. Printhead coverage explains the polygon-mirror drive, start-of-scan signals, four-color laser paths, and shutter system.

Fuser theory connects the main and sub heater lamps with the thermostat, front and rear thermistors, warm-up control, and exit sensing.

Error Diagnosis and Service-Menu Tests

Error-code tables lead to checks for named sensors, motors, clutches, controller cards, power supplies, connectors, and harnesses. Image-quality troubleshooting covers faint or blank output, solid black, lines and stripes, spots, afterimage, and background fog. Further checks address skew, media damage, unfused toner, color misregistration, deletions, and banding.

Component testing: Diagnostic functions exercise the polygon motor, PC and developer drives, transfer-belt steering and drive, registration clutch, second-transfer retract mechanism, fuser fan, toner-add motors, duplex drive, and tray-module drives. Source-specific print tests, hardware checks, feed tests, base-sensor status, and event-log display, print, and clear functions support fault isolation.

Finisher coverage: Finisher jam and service codes, mechanism tests, staple and hole-punch tests, booklet-fold adjustments, and configuration functions are included. Internal finisher teardown and repair require the separate Finisher Service Manual.

FRU Replacement and Calibration

Repair procedures cover the image-density sensor, transfer belt and cleaner, second-transfer and registration mechanisms, printhead and shutter drive, developer units and carriers, toner-add and waste-toner systems, fuser, and duplex inverter and controller.

Electrical repair coverage includes the RIP card and hard drive, upper and lower engine cards, HVPS and LVPS cards, fans, motors, sensors, and switches. Separate removal sections address all three tray modules.

Setup after repair: PH Adjust covers media-tray registration. ATC setup uses developer-unit barcode data and a conversion chart for sensitivity-gradient and sensor-output settings. RegCon includes measurement, control-sensor checks and cycles, belt-edge learning, fine and rough skew, In/Out, and center setup.

New developer units require their ATC data to be entered. The image-density sensor must be correctly positioned for RegCon center setup or the test will not function.

Handling precautions: Touching the transfer-belt surface during removal can damage it. The reassembly notes address cable-tie replacement to prevent pinched harnesses, obstructed media paths, and restricted movement.

The service-tool list specifies parallel wrap plug P/N 1319128, twinax/serial debug cable P/N 1381963, and coax/serial debug cable P/N 1381964, along with a multimeter, spring hook, and approved toner vacuum.

Preventive Maintenance and Technical Illustrations

Maintenance schedules distinguish every-service-call checks from the 100K and 600K intervals. They cover feed, pick, and separation rolls; registration and tray sensors; printhead slit glass; developer components; second-transfer roll; transfer belt and cleaner; fuser; duplex rolls; bridge-unit rolls; and finisher checkpoints.

Maintenance-kit identification, lubricant specifications, cleaning areas, and the maintenance-counter reset procedure are included.

Illustrations include SFP media-path roll and sensor maps, four-color printhead laser paths, the xerographic-process diagram, and controller/HVPS connector locations. The 5057 printer wiring diagram and 5057/7510 tray-module wiring diagram show electrical connections. Exploded assembly views and FRU tables cover the base engine and tray hardware, followed by a part-number index.

Service work requires power isolation before disconnecting boards or cables, ESD control for electronic FRUs, adequate fuser cool-down, and suitable lifting support for the printer and optional finisher assemblies.

Examples of RegCon Diagnostic Values

In the fine-skew troubleshooting chart, Patch-B in and Patch-B out are each checked against a result value of 4. The In/Out troubleshooting chart checks whether the Y, M, C, and K skew-adjustment results are all 0.