HP LaserJet 3300MFP Series Factory Service Manual, 2003 (P/N C9124-90948)

This HP factory service manual (P/N C9124-90948) covers the LaserJet 3300MFP series, including the fax-equipped 3330MFP. Its seven chapters cover operation, maintenance, diagnostics, component replacement, and parts identification.

PDF Search, Bookmarks, and Page Count

Text search and wiring detail. The main text is searchable, and embedded bookmarks link to chapters, service procedures, and the index. Small pin and connector labels in the main wiring diagrams are readable when enlarged. The labels within those diagrams are outside the text search.

The download contains one printable English-language PDF. Its 289 pages include two front cover and title pages, one back cover, and six otherwise blank divider pages.

Print Engine, Scanner, and Fax Service

These selected service topics are part of the manual’s coverage. It also explains how to run a print-path cleaning cycle and print internal configuration and service reports.

• Printer diagnostics. Engine and half self-tests, drum-rotation checks, fuser heating-element checks, and high-voltage power supply checks help trace print-quality and engine faults.
• Scanner and ADF. Covers scanner calibration, copy and scan troubleshooting, and replacement of the ADF pick roller assembly, document feed guide, separation pad, and scanner glass.
• Hardware repair. Illustrated removal and replacement procedures cover the fuser assembly, formatter, engine control unit (ECU) pan, transfer roller, paper-feed assembly, and control panel chassis.
• 3330 fax troubleshooting. Explains Line Interface Unit (LIU) operation and covers send and receive error codes, T.30 protocol traces, and developer-menu loopback and transmit tests.
• Firmware and service settings. Covers flash firmware updates, recovery DIMM use, NVRAM initialization, and Printer Job Language (PJL) commands for factory settings.
• Parts and diagrams. Includes main wiring diagrams, connector locations, exploded assembly views, voltage-specific parts lists, and estimated service lives for wear parts.

The internal repair sections are suited to printer technicians familiar with ESD precautions and electrical resistance testing.

Print Quality and Paper-Path Faults

Control panel troubleshooting covers scanner bulb failures, fuser and laser/scanner errors, and communication faults. The half self-test helps distinguish image formation or development faults from transfer or fusing problems before parts are selected.

Separate troubleshooting tables cover printer and scanner paper-feed faults. The printer timing diagram and high-voltage power supply circuit accompany explanations of ECU control, paper-path sensors, and AC, low-voltage DC, and high-voltage distribution from drum conditioning through fusing.

Scanner and ADF Replacement Scope

Parts-removal charts show when the scanner and printer must be separated. Illustrated procedures cover the printer pickup roller and control panel bezel, with reinstallation notes on cable routing, retaining tabs, and sensor flags.

The scanner assembly is replaced as a unit because opening it outside a cleanroom can contaminate the optics. That replacement includes the CCD scan module, motor, and cable. The manual also covers complete ADF replacement and separate service of accessible ADF parts.

Internal service involves mains power, a hot fuser, and the laser/scanner assembly. Follow the manual’s electrical-isolation, cooling, and protective-cover precautions. The engine-test section warns that a conductive probe at the test switch can damage the printer.

Fax Hardware and Formatter Variants

The fax sections explain how current limiting and billing-tone filtering differ between the Americas/Asia and European LIUs. The parts lists identify LIU-US and LIU-WW assemblies, copy and fax formatters, and voltage-specific fuser and ECU assemblies.

Firmware update and recovery procedures apply to flash-memory formatters. The manual also identifies permanent-ROM formatters and explains which stored faxes, regional settings, and other parameters are erased by NVRAM initialization.

Successful T.30 send and receive traces, paired with fax-phase and response tables, help identify where a failed fax departs from the normal communication sequence.

Circuit References and Parts Identification

The manual includes 44 numbered tables and 120 numbered figures. The scanner optical diagram shows the CCD light path. The main wiring and connector-location drawings help trace a circuit and locate its connector in the printer.

The repetitive image defect ruler links the spacing of recurring marks to print-cartridge, transfer-roller, and fuser components. Exploded pickup and fuser views pair callouts with part numbers. The control-panel parts table also lists 3310 and 3320 bezel entries. Reference data includes media and skew specifications, environmental limits, and regulatory information.

Fuser Resistance Reference

For the unplugged fuser check, normal heating-element resistance is 25 Ω ± 10 Ω on the 110 V model and 80 Ω ± 20 Ω on the 220 V model. Normal thermistor resistance is 370 kΩ ± 50 kΩ at 20 °C (68 °F) across each of the two specified pin pairs at J206.