Phaser 4500/4510 Service Manual 4-11
General Troubleshooting
Print Engine Troubleshooting
Main Motor 
Troubleshooting Reference 
Applicable Parts Wiring and Plug/Jack Map References
■ Main motor
■ LVPS harness assembly
■ LVPS
■ HVPS/engine logic board
■ “P4500: 24 V Interlock, Rear Cover Switch, 
Main Motor, Sub Fan, Exit Motor Assembly” on 
page 10-21
■ “Print Engine Wiring Diagrams” on page 10-19
■ “Print Engine Plug/Jack Locator” on page 10-3
Troubleshooting Procedure
Steps Actions and Questions Yes No
1 1. Remove the print cartridge.
2.Close the top cover.
3.Turn ON power and listen for the sound 
of the main motor.
Does main motor rotate?
Go to step 2. Go to step 3.
2 Is the trouble eliminated? Problem 
solved.
Go to step 3.
3 Check the LVPS harness assembly for 
continuity:
1.Remove the LVPS Shield Plate 
(page 8-60).
2.Disconnect P/J41 from the LVPS.
3.Disconnect P/J11 from the HVPS/engine 
logic board.
Is each cable of P/J41 <=> P/J11 
continuous?
Go to step 4. Replace the 
LVPS harness 
assembly.
4 1. Remove the LVPS Shield Plate. 
(page 8-60)
2.Disconnect P/J42 from the LVPS.
3.Disconnect P/J10 from the HVPS/engine 
logic board.
4.Check each wire in the LVPS harness (2) 
between P/J42 and P/J10 for continuity.
Does each wire in the harness exhibit 
continuity?
Replace the 
LVPS 
(page 8-62), 
then go to 
step 5.
Replace the 
LVPS harness 
assembly.