HP LaserJet Pro M402 Pro M403 HP LaserJet Pro MFP M426 Pro MFP M427 Full Service Manual: Repair Manual, Troubleshooting Manual and Parts List Manual

Full service manual: Repair Manual, Troubleshooting Manual and Parts List Manual HP LaserJet Pro M402d Pro M402n Pro M402dn Pro M402dw Pro M403n Pro M403d Pro M403dn HP LaserJet Pro MFP M426dw Pro MFP M426fdn Pro MFP M426fdw Pro MFP M427dw Pro MFP M427fdn Pro MFP M427fdw;
This manual is in the PDF format and have detailed Diagrams, pictures and full procedures to diagnose and repair your HP LaserJet Pro copier.
You can print, zoom or read any diagram, picture or page from this Full Service Manual. Every chapter on this manual is fully detailed and contain all the simulation codes, trouble codes, maintenance procedures, reset procedures, diagnose procedures of HP LaserJet Pro M402d Pro M402n Pro M402dn Pro M402dw Pro M403n Pro M403d Pro M403dn HP LaserJet Pro MFP M426dw Pro MFP M426fdn Pro MFP M426fdw Pro MFP M427dw Pro MFP M427fdn Pro MFP M427fdw photocopier. You can find easily everything what do you need.
To see what contain, please read table of contents:

Content for REPAIR & PARTS LIST:
1) REMOVAL AND REPLACEMENT
For additional service and support
Removal and replacement strategy
Introduction
Considerations during removal and replacement
Electrostatic discharge
Required tools
Fasteners used in this printer
Service approach
Before performing service
After performing service
Post-service test
Print-quality test
Removal and replacement procedures
Customer self-repair (CSR) A parts and assemblies
RL2-0656-000CN multipurpose tray roller
Introduction
Step 1: Remove the roller
Step 2: Unpack the replacement assembly
Step 3: Install the roller
RM2-5392-000CN 250-sheet paper input tray
Introduction
Step 1: Remove Tray 2
Step 2: Unpack the replacement assembly
Step 3: Install Tray 2
RM2-5413-000CN optional Tray 3
Introduction
Step 1: Remove optional Tray 3
Step 2: Unpack the replacement assembly
Step 3: Install optional Tray 3
RM2-5452-000CN Tray 2 paper pickup roller assembly
Introduction
Step 1: Remove Tray 2
Step 2: Remove the pickup roller assembly (Tray 2)
Step 3: Unpack the replacement assembly
Step 4: Install the pickup roller assembly (Tray 2)
Step 5: Install Tray 2
RM2-5741-000CN optional Tray 3 paper pickup roller assembly
Introduction
Step 1: Remove optional Tray 3
Step 2: Remove the paper pickup roller assembly (optional Tray 3)
Step 3: Unpack the replacement assembly
Step 4: Install the paper pickup roller assembly (optional Tray 3)
Step 5: Install optional Tray 3
RM2-5397-000CN Tray 2 separation roller assembly
Introduction
Step 1: Remove Tray 2
Step 2: Remove the separation pad roller assembly (Tray 2)
Step 3: Unpack the replacement assembly
Step 4: Install the separation pad roller assembly (Tray 2)
Step 5: Install Tray 2
RM2-5745-000CN optional Tray 3 separation roller assembly
Introduction
Step 1: Remove Tray 3
Step 2: Remove the separation roller assembly (optional Tray 3)
Step 3: Unpack the replacement assembly
Step 4: Install the separation roller assembly (optional Tray 3)
Step 5: Install Tray 3
Removal and replacement: External panels, covers, and doors
Removal and replacement: Damper sheets
Introduction
Step 1: Remove the damper sheets
Step 2: Unpack the replacement assembly
Step 3: Install the damper sheets
Removal and replacement: Rear USB cover
Introduction
Step 1: Remove the rear USB cover
Step 2: Unpack the replacement assembly
Step 3: Install the rear USB cover
Removal and replacement: Support shaft
Introduction
Step 1: Remove the support shaft
Step 2: Unpack the replacement assembly
Step 3: Install the support shaft
Removal and replacement: Cartridge door assembly
Introduction
Step 1: Remove the cartridge door assembly
Step 2: Unpack the replacement assembly
Step 3: Install the cartridge door assembly
Removal and replacement: Pressure-release link
Introduction
Step 1: Remove the cartridge door assembly
Step 2: Remove the pressure-release link
Step 3: Unpack the replacement assembly
Step 4: Install the pressure-release link
Step 5: Install the cartridge door assembly
Removal and replacement: Left cover
Introduction
Step 1: Remove the rear USB cover
Step 2: Remove the rear network cover (M402d and M403d)
Step 3: Remove Tray 2
Step 4: Remove the cartridge door assembly
Step 5: Remove the left cover
Step 6: Unpack the replacement assembly
Step 7: Install the left cover
Step 8: Install the cartridge door assembly
Step 9: Install Tray 2
Step 10: Install the rear network cover (M402d and M403d)
Step 11: Install the rear USB cover
Removal and replacement: Right cover
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the right cover
Step 4: Unpack the replacement assembly
Step 5: Install the right cover
Step 6: Install the cartridge door assembly
Step 7: Install Tray 2
Removal and replacement: Rear door assembly
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the rear door assembly
Step 6: Unpack the replacement assembly
Step 7: Install the rear door assembly
Step 8: Install the right cover
Step 9: Install the left cover
Step 10: Install the cartridge door assembly
Step 11: Install Tray 2
Removal and replacement: Cassette rear cover
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the rear door assembly
Step 6: Remove the cassette rear cover
Step 7: Unpack the replacement assembly
Step 8: Install the cassette rear door assembly
Step 9: Install the rear door assembly
Step 10: Install the right cover
Step 11: Install the left cover
Step 12: Install the cartridge door assembly
Step 13: Install Tray 2
Removal and replacement: Top cover (M427/M426)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the integrated scanner assembly (M427/M426)
Step 6: Remove the control panel (M427/M426)
Step 7: Remove the top cover (M427/M426)
Step 8: Unpack the replacement assembly
Step 9: Remove the cable guide (M427/M426)
Step 10: Install the cable guide (M427/M426)
Step 11: Install the top cover (M427/M426)
Step 12: Install the control panel (M427/M426)
Step 13: Install the integrated scanner assembly (M427/M246)
Step 14: Install the right cover
Step 15: Install the left cover
Step 16: Install the cartridge door assembly
Step 17: Install Tray 2
Removal and replacement: Cable guide (M427/M426)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the control panel (M427/M426)
Step 6: Remove the integrated scanner assembly (M427/M246)
Step 7: Remove the top cover (M427/M426)
Step 8: Remove the cable guide (M427/M426)
Step 9: Unpack the replacement assembly
Step 10: Install the cable guide (M427/M426)
Step 11: install the top cover (M427/M426)
Step 12: Install the integrated scanner assembly (M427/M246)
Step 13: Install the control panel (M427/M426)
Step 14: Install the right cover
Step 15: Install the left cover
Step 16: Install the cartridge door assembly
Step 17: Install Tray 2
Removal and replacement: Top cover (M403/M402)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the top cover (M403/M402)
Step 6: Remove the 2-line LCD operator and indication covers (M403/M402)
Step 7: Unpack the replacement assembly
Step 8: Install the 2-line LCD operator and indication covers (M403/M402)
Step 9: Install the top cover (M403/M402)
Step 10: Install the right cover
Step 11: Install the left cover
Step 12: Install the cartridge door assembly
Step 13: Install Tray 2
Removal and replacement: 2-line LCD operator and indication covers (M403/M402)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the top cover (M403/M402)
Step 6: Remove the 2-line LCD operator and indication covers (M403/M402)
Step 7: Unpack the replacement assembly
Step 8: Install the 2-line LCD operator and indication covers (M403/M402)
Step 9: Install the top cover (M403/M402)
Step 10: Install the right cover
Step 11: Install the left cover
Step 12: Install the cartridge door assembly
Step 13: Install Tray 2
Removal and replacement: Paper delivery tray (output bin)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the integrated scanner assembly (M427/M246)
Step 6: Remove the control panel (M427/M246)
Step 7: Remove the top cover (M427/M426)
Step 8: Remove the top cover (M403/M402)
Step 9: Remove the paper delivery tray (output bin)
Step 10: Unpack the replacement assembly
Step 11: Install the paper delivery tray (output bin)
Step 12: Install the top cover (M403/M402)
Step 13: Install the top cover (M427/M426)
Step 14: Install the control panel (M427/M246)
Step 15: Install the integrated scanner assembly (M427/M246)
Step 16: Install the right cover
Step 17: Install the left cover
Step 18: Install the cartridge door assembly
Step 19: Install Tray 2
Removal and replacement: Integrated scanner assembly (M427/M426)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the ISA (M427/M426)
Step 5: Unpack the replacement assembly
Step 6: Install the ISA (M427/M426)
Step 7: Install the left cover
Step 8: Install the cartridge door assembly
Step 9: Install Tray 2
Removal and replacement: ISA lift assembly and slider pin (M427/M426)
Introduction
Step 1: Remove the slider pin (M427/M426)
Step 2: Remove the ISA lift assembly (M427/M426)
Step 3: Unpack the replacement assembly
Step 4: Install the ISA lift assembly (M427/M426)
Step 5: Install the slider pin (M427/M426)
Removal and replacement: Internal parts and assemblies
Removal and replacement: Fuser
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the rear door assembly
Step 6: Remove the fuser
Step 7: Unpack the replacement assembly
Step 8: Install the fuser
Step 9: Install the rear door assembly
Step 10: Install the right cover
Step 11: Install the left cover
Step 12: Install the cartridge door assembly
Step 13: Install Tray 2
Removal and replacement: Registration assembly
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the rear door assembly
Step 6: Remove the integrated scanner assembly (M427/M246)
Step 7: Remove the control panel (M427/M426)
Step 8: Remove the top cover (M427/M426)
Step 9: Remove the top cover (M403/M402)
Step 10: Remove the paper delivery tray (output bin)
Step 11: Remove the fuser
Step 12: Remove the registration assembly
Step 13: Unpack the replacement assembly
Step 14: Install the registration assembly
Step 15: Install the fuser
Step 16: Install the paper delivery tray (output bin)
Step 17: Install the top cover (M403/M402)
Step 18: Install the top cover (M427/M426)
Step 19: Install the control panel (M427/M246)
Step 20: Install the integrated scanner assembly (M427/M246)
Step 21: Install the rear door assembly
Step 22: Install the right cover
Step 23: Install the left cover
Step 24: Install the cartridge door assembly
Step 25: Install Install Tray 2
Removal and replacement: Main motor (M1)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the right cover
Step 4: Remove the main motor (M1)
Step 5: Unpack the replacement assembly
Step 6: Install the main motor (M1)
Step 7: Install the right cover
Step 8: Install the cartridge door assembly
Step 9: Install Tray 2
Removal and replacement: Power switch printed circuit assembly
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the right cover
Step 4: Remove the power switch PCA
Step 5: Unpack the replacement assembly
Step 6: Install the power switch PCA
Step 7: Install the right cover
Step 8: Install the cartridge door assembly
Step 9: Install Tray 2
Removal and replacement: Fax PCA (M427/M426)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the fax PCA (M427/M426)
Step 5: Unpack the replacement assembly
Step 6: Install the fax PCA (M427/M426)
Step 7: Install the left cover
Step 8: Install the cartridge door assembly
Step 9: Install Tray 2
Removal and replacement: Walkup USB PCA (M427/M426)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the fax PCA
Step 5: Remove the walkup USB PCA (M427/M426)
Step 6: Unpack the replacement assembly
Step 7: Install the walkup USB PCA (M427/M426)
Step 8: Install the fax PCA
Step 9: Install the left cover
Step 10: Install the cartridge door assembly
Step 9: Install Tray 2
Removal and replacement: Wireless PCA
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the wireless PCA
Step 5: Unpack the replacement assembly
Step 6: Install the wireless PCA
Step 7: Install the left cover
Step 8: Install the cartridge door assembly
Step 9: Install Tray 2
Removal and replacement: Formatter PCA
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the fax PCA
Step 5: Remove the wireless PCA
Step 6: Remove the formatter PCA
Step 7: Unpack the replacement assembly
Step 8: Install the formatter PCA
Step 9: Install the wireless PCA
Step 10: Install the fax PCA
Step 11: Install the left cover
Step 12: Install the cartridge door assembly
Step 13: Install Tray 2
Removal and replacement: Fan (FM1)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the fan (FM1)
Step 5: Unpack the replacement assembly
Step 6: Install the fan (FM1)
Step 7: Install the left cover
Step 8: Install the cartridge door assembly
Step 9: Install Tray 2
Removal and replacement: Fan holder (FM1)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the fan (FM1)
Step 5: Remove the fan holder (FM1)
Step 6: Unpack the replacement assembly
Step 7: Install the fan holder (FM1)
Step 8: Install the fan (FM1)
Step 9: Install the left cover
Step 10: Install the cartridge door assembly
Step 11: Install Tray 2
Removal and replacement: Laser scanner assembly
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the integrated scanner assembly (M427/M246)
Step 6: Remove the control panel (M427/M246)
Step 7: Remove the top cover (M427/M426)
Step 8: Remove the top cover (M403/M402)
Step 9: Remove the paper delivery tray (output bin)
Step 10: Remove the laser scanner assembly
Step 11: Unpack the replacement assembly
Step 12: Install the laser scanner assembly
Step 13: Install the paper delivery tray (output bin)
Step 14: Install the top cover (M403/M402)
Step 15: Install the top cover (M427/M426)
Step 16: Install the control panel (M427/M246)
Step 17: Install the integrated scanner assembly (M427/M246)
Step 18: Install the right cover
Step 19: Install the left cover
Step 20: Install the cartridge door assembly
Step 21: Install Tray 2
Removal and replacement: Sheet-metal formatter bracket and formatter PCA
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the integrated scanner assembly (M427/M246)
Step 6: Remove the control panel (M427/M246)
Step 7: Remove the top cover (M427/M426)
Step 8: Remove the top cover (M403/M402)
Step 9: Remove the sheet-metal formatter bracket and formatter PCA
Step 10: Install the sheet-metal formatter bracket and formatter PCA
Step 11: Install the top cover (M403/M402)
Step 12: Install the top cover (M427/M426)
Step 13: Install the control panel (M427/M246)
Step 14: Install the integrated scanner assembly (M427/M246)
Step 15: Install the right cover
Step 16: Install the left cover
Step 17: Install the cartridge door assembly
Step 18: Install Tray 2
Removal and replacement: NFC FFC
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the integrated scanner assembly (M427/M246)
Step 6: Remove the control panel (M427/M246)
Step 7: Remove the top cover (M427/M426)
Step 8: Remove the NFC PCA cover (M427/M426)
Step 9: Remove the top cover (M403/M402)
Step 10: Remove the paper delivery tray (output bin)
Step 11: Remove the NFC PCA
Step 12: Remove the NFC FFC
Step 13: Unpack the replacement assembly
Step 14: Install the NFC FFC
Step 15: Install the NFC PCA
Step 16: Install the paper delivery tray (output bin)
Step 17: Install the top cover (M403/M402)
Step 18: Install the NFC PCA cover (M427/M426)
Step 19: Install the top cover (M427/M426)
Step 20: Install the control panel (M427/M246)
Step 21: Install the integrated scanner assembly (M427/M246)
Step 22: Install the right cover
Step 23: Install the left cover
Step 24: Install the cartridge door assembly
Step 25: Install Tray 2
Removal and replacement: Control panel FFC, (M403/M402)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the top cover (M403/M402)
Step 6: Remove the paper delivery tray (output bin)
Step 7: Remove the control panel FFC
Step 8: Unpack the replacement assembly
Step 9: Install the control panel FFC
Step 10: Install the paper delivery tray (output bin)
Step 11: Install the top cover (M403/M402)
Step 12: Install the right cover
Step 13: Install the left cover
Step 14: Install the cartridge door assembly
Step 15: Install Tray 2
Removal and replacement: Formatter FFC
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the integrated scanner assembly (M427/M246)
Step 6: Remove the control panel (M427/M246)
Step 7: Remove the top cover (M427/M426)
Step 8: Remove the top cover (M403/M402)
Step 9: Remove the sheet-metal formatter bracket and formatter PCA
Step 10: Remove the formatter FFC
Step 11: Unpack the replacement assembly
Step 12: Install the formatter FFC
Step 13: Install the sheet-metal formatter bracket and formatter PCA
Step 14: Install the top cover (M403/M402)
Step 15: Install the top cover (M427/M426)
Step 16: Install the control panel (M427/M246)
Step 17: Install the integrated scanner assembly (M427/M246)
Step 18: Install the right cover
Step 19: Install the left cover
Step 20: Install the cartridge door assembly
Step 21: Install Tray 2
Removal and replacement: DC controller
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the rear door assembly
Step 6: Remove the integrated scanner assembly (M427/M246)
Step 7: Remove the control panel (M427/M246)
Step 8: Remove the top cover (M427/M426)
Step 9: Remove the top cover (M403/M402)
Step 10: Remove the paper delivery tray (output bin)
Step 11: Remove the sheet-metal formatter bracket and formatter
Step 12: Remove the DC controller
Step 13: Unpack the replacement assembly
Step 14: Install the DC controller
Step 15: Install the sheet-metal formatter bracket and formatter
Step 16: Install the paper delivery tray (output bin)
Step 17: Install the top cover (M403/M402)
Step 18: Install the top cover (M427/M426)
Step 19: Install the control panel (M427/M246)
Step 20: Install the integrated scanner assembly (M427/M246)
Step 21: Install the rear door assembly
Step 22: Install the right cover
Step 23: Install the left cover
Step 24: Install the cartridge door assembly
Step 25: Install Tray 2
Removal and replacement: Tag-cable assembly (toner-cartridge memory)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the integrated scanner assembly (M427/M246)
Step 6: Remove the control panel (M427/M246)
Step 7: Remove the top cover (M427/M426)
Step 8: Remove the top cover (M403/M402)
Step 9: Remove the paper delivery tray (output bin)
Step 10: Remove the sheet-metal formatter bracket and formatter PCA
Step 11: Remove the tag-cable assembly (toner-cartridge memory)
Step 12: Unpack the replacement assembly
Step 13: Install the tag-cable assembly (toner-cartridge memory)
Step 14: Install the sheet-metal formatter bracket and formatter PCA
Step 15: Install the paper delivery tray (output bin)
Step 16: Install the top cover (M403/M402)
Step 17: Install the top cover (M427/M426)
Step 18: Install the control panel (M427/M246)
Step 19: Install the integrated scanner assembly (M427/M246)
Step 20: Install the right cover
Step 21: Install the left cover
Step 22: Install the cartridge door assembly
Step 23: Install Tray 2
Removal and replacement: Connecting PCA
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the integrated scanner assembly (M427/M246)
Step 6: Remove the control panel (M427/M246)
Step 7: Remove the top cover (M427/M426)
Step 8: Remove the top cover (M403/M402)
Step 9: Remove the paper delivery tray (output bin)
Step 10: Remove the sheet-metal formatter bracket and formatter PCA
Step 11: Remove the connecting PCA
Step 12: Unpack the replacement assembly
Step 13: Install the connecting PCA
Step 14: Install the sheet-metal formatter bracket and formatter PCA
Step 15: Install the paper delivery tray (output bin)
Step 16: Install the top cover (M403/M402)
Step 17: Install the top cover (M427/M426)
Step 18: Install the control panel (M427/M246)
Step 19: Install the integrated scanner assembly (M427/M246)
Step 20: Install the right cover
Step 21: Install the left cover
Step 22: Install the cartridge door assembly
Step 23: Install Tray 2
Removal and replacement: Laser scanner FFC
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the integrated scanner assembly (M427/M246)
Step 6: Remove the control panel (M427/M246)
Step 7: Remove the top cover (M427/M426)
Step 8: Remove the top cover (M403/M402)
Step 9: Remove the paper delivery tray (output bin)
Step 10: Remove the sheet-metal formatter bracket and formatter PCA
Step 11: Remove the tag-cable assembly
Step 12: Remove the laser scanner FFC
Step 13: Unpack the replacement assembly
Step 14: Install the laser scanner FFC
Step 15: Install the tag-cable assembly
Step 16: Install the sheet-metal formatter bracket and formatter PCA
Step 17: Install the paper delivery tray (output bin)
Step 18: Install the top cover (M403/M402)
Step 19: Install the top cover (M427/M426)
Step 20: Install the control panel (M427/M246)
Step 21: Install the integrated scanner assembly (M427/M246)
Step 22: Install the right cover
Step 23: Install the left cover
Step 24: Install the cartridge door assembly
Step 25: Install Tray 2
Removal and replacement: High-voltage power supply
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the integrated scanner assembly (M427/M246)
Step 6: Remove the control panel (M427/M246)
Step 7: Remove the top cover (M427/M426)
Step 8: Remove the top cover (M403/M402)
Step 9: Remove the paper delivery tray (output bin)
Step 10: Remove the sheet-metal formatter bracket and formatter PCA
Step 11: Remove the HVPS
Step 12: Unpack the replacement assembly
Step 13: Install the HVPS
Step 14: Install the sheet-metal formatter bracket and formatter PCA
Step 15: Install the paper delivery tray (output bin)
Step 16: Install the top cover (M403/M402)
Step 17: Install the top cover (M427/M426)
Step 18: Install the control panel (M427/M246)
Step 19: Install the integrated scanner assembly (M427/M246)
Step 20: Install the right cover
Step 21: Install the left cover
Step 22: Install the cartridge door assembly
Step 23: Install Tray 2
Removal and replacement: Low-voltage power supply
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the integrated scanner assembly (M427/M246)
Step 6: Remove the control panel (M427/M246)
Step 7: Remove the top cover (M427/M426)
Step 8: Remove the top cover (M403/M402)
Step 9: Remove the paper delivery tray (output bin)
Step 10: Remove the fan (FM1)
Step 11: Remove the sheet-metal formatter bracket and formatter PCA
Step 12: Remove the LVPS
Step 13: Unpack the replacement assembly
Step 14: Install the LVPS
Step 15: Install the sheet-metal formatter bracket and formatter PCA . 1008
Step 16: Install the fan (FM1)
Step 17: Install the paper delivery tray (output bin)
Step 18: Install the top cover (M403/M402)
Step 19: Install the top cover (M427/M426)
Step 20: Install the control panel (M427/M246)
Step 21: Install the integrated scanner assembly (M427/M246)
Step 23: Install the right cover
Step 24: Install the left cover
Step 25: Install the cartridge door assembly
Step 26: Install Tray 2
Removal and replacement: NFC cover (M427/M426)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 6: Remove the integrated scanner assembly (M427/M246)
Step 5: Remove the control panel (M427/M426)
Step 7: Remove the top cover (M427/M426)
Step 8: Remove the NFC cover (M427/M426)
Step 9: Unpack the replacement assembly
Step 10: Install the NFC cover (M427/M426)
Step 11: Install the top cover (M427/M426)
Step 12: install the control panel (M427/M426)
Step 12: Install the integrated scanner assembly (M427/M246)
Step 13: Install the right cover
Step 14: Install the left cover
Step 15: Remove the cartridge door assembly
Step 16: Install Tray 2
Removal and replacement: NFC PCA
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the integrated scanner assembly (M427/M246)
Step 6: Remove the control panel (M427/M426)
Step 7: Remove the top cover (M427/M426)
Step 8: Remove the NFC cover (M427/M426)
Step 9: Remove the top cover (M403/M402)
Step 10: Remove the NFC PCA
Step 11: Unpack the replacement assembly
Step 12: Install the NFC PCA
Step 13: Install the top cover (M403/M402)
Step 14: Install the NFC cover (M427/M426)
Step 15: Install the top cover (M427/M426)
Step 16: Install the control panel (M427/M426)
Step 17: Install the integrated scanner assembly (M427/M246)
Step 18: Install the right cover
Step 19: Install the left cover
Step 20: Remove the cartridge door assembly
Step 21: Install Tray 2
Removal and replacement: Control-panel assembly (M403/M402)
Introduction
Step 1: Remove Tray 2
Step 2: Remove the cartridge door assembly
Step 3: Remove the left cover
Step 4: Remove the right cover
Step 5: Remove the top cover (M403/M402)
Step 6: Remove the paper delivery tray (output bin)
Step 7: Remove the control-panel assembly (M403/M402)
Step 8: Unpack the replacement assembly
Step 9: Install the control-panel assembly (M403/M402)
Step 10: Install the paper delivery tray (output bin)
Step 11: Install the top cover (M403/M402)
Step 12: Install the right cover
Step 13: Install the left cover
Step 14: Install the cartridge door assembly
Step 15: Install Tray 2
Removal and replacement: Control panel (M427/M426) and control panel sub assemblies
Introduction
Step 1: Remove the control panel mount cover (M427/M426)
Step 2: Remove the control panel (M427/M426)
Step 3: Remove the control panel mount base (M427/M426)
Step 4: Remove the control panel mount chassis assembly (M427/M426)
Step 5: Remove Tray 2
Step 6: Remove the cartridge door assembly
Step 7: Remove the left cover
Step 8: Remove the control panel 22-pin FFC (M427/M426)
Step 9: Unpack the replacement assembly
Step 10: Install the control panel 22-pin FFC (M427/M426)
Step 11: Install the left cover
Step 12: Install the cartridge door assembly
Step 13: Install Tray 2
Step 14: Install the control panel mount chassis assembly (M427/M426)
Step 15: Install the control panel mount base (M427/M426)
Step 16: Install the control panel (M427/M426)
Step 17: Install the control panel mount cover (M427/M426)
Removal and replacement: Trays
Removal and replacement: Tray 2
RM2-5392-000CN 250-sheet paper input tray
RM2-5452-000CN Tray 2 paper pickup roller assembly
RM2-5397-000CN Tray 2 separation roller assembly
Removal and replacement: Accessories
550-sheet paper feeder
C5F97-69001 optional 550-sheet paper feeder
RM2-5413-000CN optional Tray 3
RM2-5741-000CN optional Tray 3 paper pickup roller assembly
RM2-5745-000CN optional Tray 3 separation roller assembly
For additional service and support

2) PARTS AND DIAGRAMS
Order parts, accessories, and supplies
Ordering
Orderable parts
Supplies
Accessories
Customer self-repair parts
How to use the parts lists and diagrams
Document feeder and image scanner
Main assemblies
Covers, printer base
Covers, M402 and M403
Covers, M426 and M427
Internal components, printer base
Internal components, printer base (1 of 3)
Internal components, printer base (2 of 3)
Internal components, printer base (3 of 3)
550-sheet paper feeder
Covers, 550-sheet paper feeder
Main body, 550-sheet paper feeder
Alphabetical parts list
Numerical parts list
Index

____________________________________

Content TROUBLESHOOTING MANUAL:
1) THEORY OF OPERATION
Related documentation and software
Basic operation
Sequence of operation
Engine-control system
DC controller
Motor control
Fan control
Low-voltage power supply
Over-current/over-voltage protection
Safety
Low-voltage power supply functions
High-voltage power supply
High-voltage power supply circuits
Fuser bias
Fuser control
Fuser circuits
Fuser control functions
Fuser heater protection
Engine laser/scanner system
Laser/scanner failure detection
Safety
Image-formation process
Step 1: Primary charging
Step 2: Laser-beam exposure
Step 3: Development
Step 4: Transfer
Step 5: Separation
Step 6: Fusing
Step 7: Drum cleaning
Toner cartridges
Design
Memory chip
Toner level and cartridge life detection
Pickup, feed, and delivery system
Sensors and switches
Motors, clutches, and solenoids
Jam detection/prevention
Paper feeder (optional Tray 3)
Basic operation
Paper path
Paper feeder controller
Motor control
Pickup and feed operation
Electrical components, pickup and feed
Other functions
Jam detection

2) SOLVE PROBLEMS
For additional service and support
Solve problems checklist
Solve problems checklist
Print the menu map
Print a configuration page
Print the service page (includes the event log)
Print the demo page
Troubleshooting process
Determine the problem source
Pre-troubleshooting checklist
Determine the problem source
Power subsystem
Power-on checks
Control panel checks
Tools for troubleshooting
Component diagnostics
LED diagnostics
Network LEDs (network models only)
Control panel LEDs
Engine diagnostics
Engine test
Diagrams
Diagrams: Block diagrams
Cross-sectional view of printer
Cross-sectional view of 550-sheet paper feeder
Diagrams: Printed circuit assembly (PCA) connector locations
Diagrams: DC controller connections
Paper feeder controller PCA
Diagrams: External plug and port locations
Diagrams: Locations of major components
Major components (printer base)
Motor and fan
Rollers and pads (printer base)
PCAs (printer base)
Diagrams: Timing chart
Diagrams: Circuit diagrams
Advanced configuration with HP Embedded Web Server (EWS) and HP Device Toolbox (Windows 7)
Internal print-quality test pages
Clean the paper path
Clean the paper path (LCD control panel)
Clean the paper path (touchscreen control panel)
Print the configuration page
Print the configuration page from an LCD control panel
Print the configuration page from a touchscreen control panel
Print-quality troubleshooting tools
Repetitive image defect ruler
Use a ruler to measure between repetitive defects
Control panel menus
HP Web Services menu
Reports menu
Quick Forms menu
USB Flash Drive menu
System Setup menu
Service menu
Network Setup menu
Control panel message document (CPMD)
Control-panel message types
Control-panel messages and event log entries
30.XX Error Messages
49.XX.YY Error Messages
50.XX fuser errors
51.XX and 52 Laser/Scanner Errors
55.XXXX Error Messages
57.XX Error Messages
58.XX Error Messages
59.XX Error Messages
79 Errors
Alpha Error Messages
Event-log messages
Print the event log
Print the event log (LCD control panel)
Print the event log (touchscreen control panel)
Show an event log
Event-log messages
Clear paper jams
Clear paper jams (M402, M403)
Introduction
Experiencing frequent or recurring paper jams?
Jam locations
Clear paper jams in Tray 1
Clear paper jams in Tray 2
Clear paper jams in optional Tray 3
Clear paper jams in the fuser
Clear paper jams in the output bin
Clear paper jams in the duplexer
Clear paper jams (M426, M427)
Introduction
Experiencing frequent or recurring paper jams?
Jam locations
Clear paper jams in the document feeder
Clear paper jams in Tray 1
Clear paper jams in Tray 2
Clear paper jams in optional Tray 3
Clear paper jams in the fuser
Clear paper jams in the output bin
Clear paper jams in the duplexer
Solve paper-handling problems
The printer picks up multiple sheets of paper
The printer does not pick up paper
Solve image quality problems
Print quality examples
Clean the printer
Clean the pickup and separation rollers
Clean the paper path
Clean the paper path (LCD control panel)
Clean the paper path (touchscreen control panel)
Clean the touchscreen
Solve performance problems
Factors affecting print performance
Print speeds
The product does not print or it prints slowly
The product does not print
The product prints slowly
Solve connectivity problems
Solve direct-connect problems
Solve network problems
Poor physical connection
The computer is using the incorrect IP address for the product
The computer is unable to communicate with the product
The product is using incorrect link and duplex settings for the network
New software programs might be causing compatibility problems
The computer or workstation might be set up incorrectly
The product is disabled, or other network settings are incorrect
Solve wireless network problems
Wireless connectivity checklist
The control panel displays the message: The wireless feature on this product has been turned off
The product does not print after the wireless configuration completes
The product does not print, and the computer has a third-party firewall installed
The wireless connection does not work after moving the wireless router or product
Cannot connect more computers to the wireless product
The wireless product loses communication when connected to a VPN
The network does not appear in the wireless networks list
The wireless network is not functioning
Service mode functions
Service menu
Service menu settings
Restore the factory-set defaults
Restore the factory-set defaults (LCD control panel)
Restore the factory-set defaults (touchscreen control panel)
Secondary service menu
Open the secondary service menu
Open the secondary service menu (LCD control panel)
Open the secondary service menu (touchscreen control panel)
Secondary service menu structure
Developer’s menu
Open the Developer’s menu (LCD control panel)
Open the Developer’s menu (touchscreen control panel)
Product resets
NVRAM initialization
Solve fax problems (fax models only)
Introduction
Fax troubleshooting checklist
Solve general fax problems
Faxes are sending slowly
Fax quality is poor
Fax cuts off or prints on two pages
Solve email problems (M426, M427 printes)
Cannot connect to the email server
Validate the SMTP gateway (Windows)
Validate the LDAP gateway (Windows)
Manually update the firmware
Manually update the firmware (LCD control panel)
Manually update the firmware (touchscreen control panel)

Appendix A Printer specifications
Printer dimensions M426 and M427
Printer dimensions M402 and M403
Printer space requirements
Power consumption, electrical specifications, and acoustic emissions
Operating-environment range
Certificate of Volatility
Index

Number of pages: 1532.