1995–1996 HP LaserJet 5P/5MP & 6P/6MP Service Manual (P/N C3980-99001)

This 212-page PDF brings together two related HP service-supplement sections for the LaserJet 5P/5MP and 6P/6MP families. The first 97-page segment contains the earlier 5P/5MP material and its reader comment sheet; the following 115 pages are Hewlett-Packard publication C3980-99001, first edition, August 1996. Coverage is identified by product number: 5P C3150A, 5MP C3155A, 6P C3980A, and 6MP C3982A.

This supplement is best suited to technicians who already understand LaserJet print-engine service and have access to HP’s earlier 4L/4ML and 4P/4MP Combined Service Manual. HP treats it as a supplement: it documents the service and repair information unique to these models while directing shared repair processes to the earlier manual.

• Model-specific coverage separates 5P/5MP and 6P/6MP status panels, printer languages, memory configurations, infrared performance, jam-page behavior, and model- or voltage-specific replacement parts.
• Removal and replacement procedures cover the power door, I/O cover, left side and top covers, Tray 1 pickup assembly and roller, formatter board and shield, fusing assembly, and DC Controller Assembly.
• Fault isolation addresses continuable data errors, Error 53 ROM/RAM and SIMM codes, fuser faults, main-motor failures, SIMM parity and memory problems, internal RAM and scan-buffer errors, Video DMA timeouts, and Dynamic RAM Controller faults.
• Print-engine references map the paper path through sensors PS1-PS5, solenoids SL1 and SL2, the registration points, fuser, delivery rollers, and the DC Controller PCA.
• Service-mode coverage includes PJL-controlled page-count settings, cold-reset defaults, diagnostics, test pages, continuous self-test, NVRAM initialization, Resource Saving, I/O buffering, and the 6P/6MP Job Cancel functions.
• Interface troubleshooting explains IEEE-1284 B- and C-type parallel connections, LocalTalk, automatic I/O switching, IrDA protocol layers, host configuration checks, and use of the Genoa infrared test tool.
• Parts identification includes two eight-view exploded-parts sections. The earlier set covers 5P/5MP assemblies; the later set adds 6P/6MP-specific parts, with item callouts and material lists for each assembly group.

Model and Configuration Differences

The 5P/5MP engine is rated at 6 pages per minute and uses Enhanced PCL 5; the 6P/6MP is rated at 8 pages per minute and uses PCL 6. The MP configurations add PostScript Level 2 and carry 3 MB of standard memory rather than the 2 MB fitted to the 5P and 6P. All four models support 600 dpi output with Resolution Enhancement Technology. Resource Saving requires PostScript and at least 7 MB of memory, while user-adjustable I/O buffering requires at least 6 MB.

Controls and job recovery are not identical across the family. The 5P/5MP uses a Reset button, while the 6P/6MP substitutes Job Cancel and relocates the tray-status lights. The 6P also changes automatic reprinting after a paper jam when standard memory is installed; the related PJL REPRINT setting and its performance tradeoff are explained. Infrared hardware is another real variant: the 5P/5MP operates at 115 kbps, while the 6P/6MP supports speeds up to 4 Mbps.

Diagnostics, Schematics, and Repair Cautions

Ten fault and electrical-check tables translate primary and secondary LED patterns into specific error families and component checks. Fuser diagnosis covers DC Controller connector contact, thermistor testing, and thermal-fuse continuity. The main-motor chart traces faults through the DC Controller, gear train, cartridge rotation, fan, and Laser/Scanner Assembly rather than stopping at the displayed code.

Named illustrations include the HP LaserJet 5P/6P Printer Paper Path, IR Data Flow, Interface Connections, Secondary Light Patterns, Main Wiring Diagram, and HP LaserJet 5P/6P Fusing Assembly exploded view. Parts tables distinguish 5P/5MP from 6P/6MP assemblies and separate the 100-120V and 220-240V DC controllers, fusers, and fuser-film assemblies before repair parts are selected.

Disconnect the printer from power before service, protect the PCAs from ESD, and never operate or service the unit with the Laser/Scanner protective cover removed. Allow the fuser to cool before handling it.

When the top cover is refitted, the Tray 1 paper-out flag must sit in the lift-plate groove; forcing the cover can break the flag. For DC Controller repair, the formatter and fuser must be removed first or the printer can be damaged, and the controller interconnect plus Tray 1 interconnect PCA and cable must be retained because they are not supplied with the replacement board.