User Guide

Failure detection.................................................................................................................154
Drum motor failure detection..............................................................................155
Fuser motor failure detection.............................................................................155
ETB motor failure detection...............................................................................155
Rear exhaust fan failure detection.....................................................................155
Cartridge fan failure detection............................................................................155
Delivery fan failure detection..............................................................................155
Power supply fan failure detection.....................................................................156
Scanner fan failure detection.............................................................................156
ADF fan failure detection....................................................................................156
Control fans #1 and #2 failure detection............................................................156
Sub power supply fan failure detection..............................................................156
ETB fan failure detection....................................................................................156
Low-voltage power supply..................................................................................................156
Fuser control circuit............................................................................................157
Low-voltage power supply circuit.......................................................................159
Protective functions...........................................................................160
Safety................................................................................................160
Sleep mode.......................................................................................160
Power supply recognition..................................................................160
Heater temperature control.................................................................................................160
Initial rotation temperature control.....................................................................161
Start-up temperature control..............................................................................161
Print temperature control....................................................................................162
Between-sheets temperature control.................................................................162
Temperature protective function.........................................................................................162
Protective function by the CPU..........................................................................162
Protective function by the fuser heater safety circuit.........................................162
Protective function by the thermoswitch............................................................163
Temperature failure detection.............................................................................................163
Start-up failure (warm-up failure).......................................................................163
Abnormal low temperature of main thermistor (no conduction).........................163
Abnormal high temperature of main thermistor.................................................163
Abnormal low temperature of sub thermistor (no conduction)...........................163
Abnormal high temperature of sub thermistor...................................................164
Drive circuit abnormality.....................................................................................164
High-voltage power supply.................................................................................................164
Generation of biases..........................................................................................165
Sub power supply assembly...............................................................................................167
Video interface control........................................................................................................167
Laser/scanner system.........................................................................................................................169
Laser control.......................................................................................................................170
Scanner control...................................................................................................................171
Image formation system......................................................................................................................173
Image formation process....................................................................................................174
Electrostatic latent image formation block..........................................................................176
Step 1: Pre-exposure.........................................................................................176
Step 2: Primary charging....................................................................................177
Step 3: Laser beam exposure............................................................................177
Development block.............................................................................................................177
ENWW ix