Xerox Phaser 4500, Service Manual

Page: 168 / 537

General Troubleshooting 4-15
9 Check the /ROSMOT ON signal of the
Scanner Motor:
1. Install the Print Cartridge.
2. Close the Top Cover.
3. Measure the voltage across P/J13-3 <=>
P/J13-2 on the HVPS/Engine Logic
Board.
Does the voltage measure 0 V just after
the power is turned ON, and 5 VDC 10
seconds after stopping Main Motor?
Go to step 11. Go to step 10.
10 Check the Laser Unit Harness Assembly:
1. Disconnect P/J13 from the HVPS/
Engine Logic Board.
2. Test each conductor in the harness
P/J13 <=> P/J130 for continuity.
Do all the conductors exhibit
continuity?
Replace the
HVPS/Engine
Logic Board.
(page 8-89)
Replace the
Laser Unit
Harness
Assembly.
11
Check the Laser Unit Harness Assembly:
1. Disconnect P/J17 and P/J16 from the
HVPS/Engine Logic Board.
2. Disconnect P/J170 and P/J160 from
Laser Unit Assembly.
3. Measure the following for continuity:
■
P/J17 <=> P/J170
■
P/J16 <=> P/J160
Do the conductors exhibit continuity?
Go to step 12. Replace the
Laser Unit
Harness
Assembly.
12 Check the SOS power circuit of the Laser
Unit Assembly:
1. Disconnect P/J140 from Laser Unit
Assembly.
2. Measure the following for continuity:
■
P/J140-8 <=> P/J201-1
■
P/J140-6 <=> P/J201-2
■
P/J140-7 <=> P/J201-3
Do the conductors exhibit continuity?
Go to step 13. Replace the
Laser Unit
Assembly
(page 8-46).
13 Replace the HVPS/Engine Logic Board
(page 8-89).
Does the problem still occur after
replacement? Go to step 14. Problem solved.
14 Replace the Laser Unit Assembly
(page 8-46
Does the problem still occur after
replacement? Go to Electrical
Noise.
Problem solved.
Troubleshooting Procedure (Continued)
Steps Actions and Questions Yes No