Phaser 4500/4510 Service Manual 3-31
Error Messages and Codes
Fan Failure
Diagnostic Error Code
U-5: Fan Fail
Troubleshooting Reference
Applicable Parts Wiring and Plug/Jack Map References
■ Main fan
■ Sub Fan
■ LVPS
■ HVPS/engine logic board
■ “150-Sheet Feeder, 550-Sheet Feeder, Main
Fan” on page 10-27
■ “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 Turn the power ON.
Does the main fan rotate?
Go to step 2. Go to step 3.
2 Does the Sub Fan rotate when the
power is turned ON?
Go to step 3. Go to step 9.
3 Enter Service Diagnostics, and from the
Motors/Fan Test menu select the
Fan Motors High Speed test.
Does the main fan rotate at high-
speed?
Go to step 4. Go to step 5.
4 Enter Service Diagnostics, and from the
Motors/Fan Test menu select the
Fan Motors High Speed test.
Does the Sub Fan rotate at high-
speed?
Replace the
HVPS/engine
logic board
(page 8-73).
Go to step 9.
5 Measure the voltage across P/J24-18
<=> P/J24-17 on HVPS/Main Logic
board.
Does the voltage measure 24 VDC?
(12 VDC at low-speed)
Go to step 6. Replace the
LVPS
(page 8-62)
then go to step
8.
6 Measure the voltage across P/J24-17
<=> P/J24-16.
Does the voltage measure 0.82 VDC
or higher?
Replace the
main fan
(page 8-68)
then go to step
7.
Replace the
HVPS/engine
logic board
(page 8-73).
7 Turn the power ON.
Does the fan error occur when the
power is turned ON?
Go to step 8. Problem solved.