HP LaserJet Pro 400 color M451 - Page 9

Duplex reverse-drive assembly ................................................................... 89
Remove the duplex reverse-drive assembly .................................... 89
Fuser ...................................................................................................... 92
Remove the fuser ....................................................................... 92
Reinstall the fuser ...................................................................... 97
Paper-delivery assembly ............................................................................ 98
Remove the paper-delivery assembly ............................................ 98
2 Solve problems ............................................................................................................................... 101
Solve problems checklist ....................................................................................................... 102
Menu map .......................................................................................................................... 102
Troubleshooting process ........................................................................................................ 103
Pretroubleshooting checklist .................................................................................... 103
Power-on checks ................................................................................................... 105
Tools for troubleshooting ....................................................................................................... 106
Engine diagnostics ................................................................................................ 106
Diagrams ............................................................................................................. 106
Plug/jack locations ................................................................................. 106
Location of connectors ............................................................................ 107
DC controller PCA ................................................................... 107
Location of major components ................................................................. 108
Major components .................................................................. 108
Solenoids, clutches, and sensors ............................................... 109
Rollers .................................................................................... 111
Motors and fans ...................................................................... 112
PCAs ..................................................................................... 113
General timing charts ............................................................................. 114
General circuit diagram .......................................................................... 115
CPU/ASIC diagrams .............................................................................. 116
HVT/Toner EMP diagram ........................................................................ 118
Driver PCA diagram ............................................................................... 119
Duplexer PCA diagram ........................................................................... 120
FSR diagram .......................................................................................... 121
Internal print quality test pages ............................................................................... 122
Print quality troubleshooting page ............................................................ 122
Print quality assessment page .................................................................. 122
Print the configuration page ..................................................................... 122
Print-quality troubleshooting tools ............................................................................ 123
Repetitive image defects .......................................................................... 123
Calibrate the product .............................................................................. 123
Control panel menus .............................................................................................. 124
ENWW vii
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