Xerox Phaser 4500, Service Manual

Page: 167 / 537

4-14 Phaser 4500 Service Manual
4 Check the LVPS Harness:
1. Disconnect P/J141 of the LVPS Harness
(near the Laser Unit PWBA).
2. Test for continuity between P/J141-1
<=> P/J141-3 while opening and closing
the Top Cover.
Is there continuity when the Top Cover
is closed, and no continuity when the
Top Cover is open?
Go to step 5. Replace the
LVPS Harness
Assembly.
5
Check the Laser Unit Harness:
1. Disconnect P/J14 from the HVPS/
Engine Logic Board.
2. Disconnect P/J140 from Laser Unit
Assembly.
3. Test for continuity between P/J14-1 <=>
P/J140-8 while opening and closing the
Top Cover.
Is there continuity when the Top Cover
is closed, and no continuity when the
Top Cover is open?
Go to step 6. Replace the
Laser Unit
Harness
Assembly.
6
Check power to the HVPS/Engine Logic
Board:
1. Remove the LVPS Shield Plate
(page 8-75).
2. Install the Print Cartridge.
3. Disconnect P/J41 from the LVPS.
4. Measure the voltage across P/J41-4 <=>
P/J41-3 on the board.
Does the voltage m5 VDC?
Go to step 7. Replace the
LVPS
(page 8-78).
7 Check the HVPS/Engine Logic Board for
continuity:
Disconnect P/J14 and P/J11 from the
HVPS/Engine Logic Board.
Test for continuity between P/J14-1 <=>
P/J11-13.
Is there continuity? Go to step 8. Go to step 13.
8 1. Disconnect P/J11 from the HVPS/
Engine Logic Board.
2. Test for continuity between P/J11-13
<=> P/J41-4.
Is there continuity?
Go to step 9. Replace the
LVPS Harness
Assembly (1).
Troubleshooting Procedure (Continued)
Steps Actions and Questions Yes No