Z840/Z850 Electronics Troubleshooting Guide - Xerox Phaser 840 Service Manual

Z840/Z850 Electronics Troubleshooting Guide

This troubleshooting guide is composed of two sections. The first section is to be used for printer failures
that occur during the printer's power on sequence.
The second section is to be used for all other failures relating to electronics that can occur at any point other
than during the power on sequence.
Failures Occurring During Power On Sequence
I. No Lights, No Sound
ADDITIONAL CLUES
1.
Fan twitches; lights may
flash on for a moment.
2.
No reaction to power
switch; fan does not
move lights don't blink.
PROBABLE ROOT CAUSE
A. Short in power system.
A. No wall power.
B. Power supply failed.
C. Short in power system.
ACTIONS (follow in order)
A1. Check for shorted motor
drivers on power control
board by removing 40V
Jumper and replace it with
40V Service Plug.
A2. If the printer powers up
with 40 V Service Plug, put
40 V Jumper back in place
and systematically remove
cables from power control
board until it does power
up; replace appropriate
part.
If printer still does not work
after removing cables from
power control board,
replace power control
board.
A3. If it does not power up
with 40 V Service Plug,
replace power supply. If it
still does not power up with
new power supply, replace
main board.
2A. Check wall power. for
proper voltage.
2B. Check power supply
fuses F1, F2, and F3 to
line. If open, replace
power supply.
2C. Check for shorted motor
drivers on power control
board as in step 1a.
Appendix 253