Lexmark E450DN Printer Service Manual (P/N 12G9709)

• Factory service manual for the monochrome Lexmark E450dn, machine type 4512-630—a 158-page PDF, P/N 12G9709, edition August 30, 2007.
• 13 targeted service checks covering controller-card and LVPS/HVPS faults, cooling fan and cover-interlock operation, main-motor failures, and print-quality problems.
• Paper-feed repair procedures for autocompensator clutches and drive shafts, manual-feed solenoids, pick tires, tray wear strips, and the duplex gear drive.
• Removal and installation coverage for the belt fuser, main motor drive, developer drive coupling, transfer roll, and operator panel, with component-specific reassembly notes.
• Printhead replacement with mechanical and electronic alignment, print registration, and duplex margin verification.
• The E450 DN Wiring Diagram is paired with controller-card connector pin-value lookups for electrical troubleshooting.

Maintenance and Diagnostic Procedures

This service manual breaks down the complete startup sequence and power-on self-test (POST) stages. Its error tables separate 200-series paper jams from 9xx service faults and link symptoms to the appropriate service checks. Input-tray and output-bin feed tests check paper transport, while the Base Sensor Test reports input, exit, and front-door sensor states. Duplex tests include sensor checks and the Duplex Feed 1 paper-stop test.

Hardware tests cover DRAM, the display, and operator-panel buttons. The Parallel Wrap test specifies test plug P/N 1319128. Event Log coverage explains why a log printed from Diagnostics provides debug information and secondary 900-series codes that are absent from the Configuration Menu version.

Printer Setup covers Configuration IDs used after system-board replacement. EP Setup addresses fuser-temperature options, transfer, print contrast, charge roll, and interpage gap adjustment.

Repair, Adjustment, and Parts Identification

Separate removal sections cover the manual-feed and input/duplex sensors, along with the narrow-media and toner-level sensors. The printhead chapter distinguishes paper-feed skew from mechanical head misalignment; its Visual alignment printout supports final alignment verification. Exploded views titled Assembly 2: Electronics and Assembly 3: Frame connect illustrated components with FRU part-number listings.

The repair notes warn that replacing the controller card and operator panel together can erase critical factory settings. Transfer-roll handling precautions address surface damage from finger oils.

Technical Data Preview

Electrical reference data covers the controller-card supply at J19, main-motor connections at J17, and fuser-thermistor checks at J13. Connector tables distinguish signals, grounds, and readings with cables connected or disconnected. Service checks provide the related voltage, resistance, and continuity criteria for board and cable fault isolation.

The Paper path diagram identifies sensing points through the fuser and duplex route. The Print defects guide uses repeating defect patterns to distinguish photoconductor-kit, toner-cartridge, transfer-roll, and fuser problems.

Before disconnecting cables or removing the fuser, power supply, or electronic cards, always verify the machine is fully disconnected from power to prevent electrical shock and logic board damage.

Preventive Maintenance and Parts Variants

Maintenance coverage includes the safety inspection guide, maintenance-counter reset, and kit contents. The parts listings distinguish 100 V, 110 V, and 220 V fuser and maintenance-kit versions, plus 110 V and 220 V LVPS/HVPS assemblies. Lubrication is specified for replacement work or as needed, not as a routine scheduled task; the manual identifies Nyogel 744, P/N 99A0394.

Included Bulletins and Model Coverage

The package totals 413 pages across 22 PDFs: the 158-page service manual, a 201-page Service Tips archive, and 20 service bulletins totaling 54 pages. The archive and bulletins cover multiple Lexmark families, so their applicability varies by document.

E450dn-applicable bulletins add Tray 2 cable-fault diagnosis, exit-sensor flag revisions, and checks for updated pick-clutch linkage parts. Bulletin E_Series_111 explains how an older printhead can cause 200.04, 200.08, and 200.29 paper-jam messages. It distinguishes November 2007-and-earlier printer builds from December 2007-and-later production, with an additional check of the installed printhead's date code.

The main repair manual is specific to the E450dn; E250d/dn and E350d/E352dn machines use separate service manuals.