Lexmark X651de, X652de, X654de, X656de, X658de Service Manual (P/N 12G9823)

Lexmark OEM Service Manual P/N 12G9823 is a 663-page PDF for Machine Type 7462, revised September 21, 2010. It covers the X651de, X652de, X654de, X656de, X656dte, X658d, X658de, X658dme, X658dfe, X658dte, X658dtme, and X658dtfe. The maintenance information is expressly prepared for professional service personnel; this is shop-level repair documentation for technicians equipped to work around live power-supply circuits, laser assemblies, hot fuser parts, and heavy floor-standing configurations.

• Diagnostic coverage starts with installation checks and the Power-On Reset sequence, then moves through user messages, code-specific fault descriptions, possible FRU actions, and linked service checks for printer, scanner/ADF, network, and option failures.
• Service-mode testing includes printer registration and print-quality pages; DRAM, cache, USB, disk, and base-sensor tests; duplex motor, sensor, margin, and feed checks; tray and output-bin tests; scanner feed, sensor, ASIC, and back-side uniformity checks; EP setup; and event-log functions.
• Core repair procedures cover polygon printhead registration, alignment and skew correction, fuser-solenoid and gap adjustment, plus illustrated removal and installation of the fuser, printhead, duplex, main-drive/redrive, LVPS, HVPS, system-card, transfer, charge-roll, scanner, and ADF assemblies.
• Option repair sections address the HCIT and 250-/550-sheet drawers, tray controller cards, sensors, lift and pick drives, as well as the MFP stapler, offset stacker, and 4-bin mailbox. The fault tables and parts catalog also cover the envelope feeder.
• Model-specific paths separate many X658 procedures from those for the X651/X652/X654/X656 chassis. Duplex-ADF CCD service is identified for X654, X656, and X658 machines, and the manual distinguishes Type 1 and Type 2 fuser configurations.
• Technical drawings and reference sheets include the X651/X652/X654/X656 and X658 paper-path roll-and-sensor maps, the printer/tandem-tray cross section, ADF and flatbed sensor-location views, 32 illustrated parts-catalog assembly groups, the “7462 MFP” and “7462 MFP SCANNER/ADF” wiring diagrams, and a Print Defects Guide for repeating marks.

Fault Isolation and Image-Quality Diagnosis

The error-code section links symptoms to checks and likely field-replaceable units instead of stopping at a code definition. Coverage includes printhead laser-start, motor-synchronization, polygon-mirror, and laser-power faults; main-drive mechanical-load errors; fuser warm-up, temperature, lamp, and voltage-mismatch faults; duplex, tray, HCIT, output-option, scanner/ADF, fan, system-card, memory, and NVRAM failures. Separate symptom tables work through faint or blank output, solid black pages, horizontal or vertical banding, spots, ghosting, background, skew, media damage, and unfused toner. ADF/scanner image-quality faults and wired or wireless network checks are also included.

The Diagnostics and Configuration menus support post-repair verification as well as fault isolation. Procedures cover registration, duplex top margin, scanner manual registration, maintenance-counter reset, configuration IDs, fuser and electrophotographic settings, sensor response, feed operation, print-quality pages, and event-log review. The disk test/clean and wipe functions carry explicit data-loss warnings.

Configuration, Parts, and Repair Scope

The configuration table differentiates simplex-ADF and duplex-ADF machines, modem-equipped versions, and hard-drive configurations. Media-reference tables cover supported sizes, types, weights, input sources, duplex restrictions, and output options. Printer theory explains the media path, xerographic process, printhead SOS control, fuser control, scanner and ADF operation, drive systems, and LVPS/HVPS functions.

Type 1 and Type 2 fusers are separated by detac design and expected service life, with maintenance-kit identification for 100 V, 110 V, and 220 V machines. The switchable LVPS section identifies its logic, laser-diode, and fan supplies, while the parts catalog supplies FRU numbers and exploded views for the base MFP and covered accessories. The required-tool list is limited to normal hand tools, a spring hook, and an analog or digital multimeter; the repair approach is FRU-level removal, replacement, adjustment, and verification rather than board-level electronic repair.

The manual calls out several installation traps. During an NVRAM mismatch repair, the scanner interface card and system card must not be replaced together before the specified Power-On Reset, or the MFP can be rendered inoperable. It also warns that an incorrect LVPS voltage-selector setting can cause damage, and that misalignment during main-drive installation can damage the gears or drive shafts.