Xerox Phaser 4500, Service Manual

Page: 180 / 537

General Troubleshooting 4-27
Troubleshooting Procedure
Steps Actions and Questions Yes No
1 Check the 5 V Interlock:
1. Disconnect P/J142.
2. Test for continuity across P/J142-1 <=>
P/J142-2 while manually operating the
switch.
Is the switch continuous when pushed
and open when released?
Go to step 2. Replace the 5 V
Interlock
(page 8-49).
2 Check the Interlock Switch Assembly
1. Disconnect P/J144.
2. Test for continuity across P/J144-1 <=>
P/J144-2 while manually operating the
Laser Interlock.
Is the switch continuous when pushed
and open when released?
Go to step 3. Replace the
Interlock Switch
Assembly
(page 8-13).
3 Check the LVPS Harness Assembly
1. Disconnect P/J141, P/J142 and P/J144
of LVPS Harness Assembly.
2. Test for continuity across the following
points:
■
J141-2 <=> P142-1
■
J141-1 <=> P144-2
■
J142-2 <=> P144-1
Are all continuous?
Go to step 4. Replace the
LVPS Harness
Assembly.
4 Check the Laser Unit Harness Assembly:
1. Disconnect P/J141, P/J14 and P/J140 of
the Laser Unit Harness Assembly.
2. Test for continuity across the following
points:
■
P141-1 <=> J14-1
■
P141-2 <=> P140-8
Are both continuous?
Go to “LVPS (Low
Voltage Power
Supply)” on
page 4-4.
Replace the
Laser Unit
Harness
Assembly.