Xerox Phaser 8400 Service Manual page 206

2.
Transient on AC line tripped protective circuitry in printer power supply.
a. Cycle power to printer to reset protective circuits in power supply.
3. Short circuit on 3.3 V power supply within the electronics module. ESD damage
to the printer may occur if static electricity is discharged to printer electronics
a.
With power cord connected, touch the metal electronics module to discharge
any static electricity.
b.
Turn off printer and wait 30 seconds for power supply capacitors to
discharge. Damage to circuits within the electronics module may occur if the
power supply capacitors are not allowed to fully discharge.
c. Unplug power cord and remove printer's covers.
Caution
Use caution around motors, pulleys and live AC connections when working
with the printer covers off.
d. Unplug the following electronics module connectors: This step removes all
other circuits so the electronics module can be tested alone.
■
Power Control to I/O board (J800)
■
Power Control right (J400)
■
Preheater solenoid (interconnect cable)
■
Printhead tilt gear solenoid (interconnect cable)
■
Printhead data (J130)
■
Waveamp signal (J790)
■
Power Control left (J390)
■
Y-Axis motor (J280)
e. Plug in power cord and turn on power to the printer
f.
If the PE and PS indicators do not flash momentarily, the short is inside the
electronics module. Replace the electronics module and retest the printer. If
PE and PS indicators flash, continue with debug.
g. Plug in all cables removed during service.
h.
Trace through all service steps performed to reattach any cables that were
unplugged during debugging.
i. Attach printer covers.
j.
Perform full test of printer.
4.
Short circuit on 3.3 V power supply within the I/O board.
a. REQURIED: Follow all procedures from Step 3 before proceeding with
these steps. The I/O board needs to be isolated from other systems in the
printer to be effectively tested.
b. Turn off printer and wait 30 seconds for power supply capacitors to
discharge. Damage to circuits within the electronics module may occur if the
power supply capacitors are not allowed to fully.
c.
Unplug the Control Panel connector (J220) on the I/O board. This removes
the Control Panel from the I/O board.
4-66 Phaser 8400/8500/8550 Color Printer