Phaser 4500/4510 Service Manual 3-73
Error Messages and Codes
No Recognition of Duplex Unit
Troubleshooting Reference
Applicable Parts Wiring and Plug/Jack Map References
■ HVPS/engine logic board
■ LVPS harness assembly
■ Duplex unit PWBA
■ Duplex unit assembly harness
■ “Duplex Unit Signal Diagram” on page 10-35
■ “Duplex Unit General Wiring Diagram” on
page 10-34
■ “Duplex Unit Plug/Jack Locator” on page 10-14
Troubleshooting Procedure
Steps Actions and Questions Yes No
1 Check the duplex unit detection signal:
1.Remove the duplex unit PWBA
(page 8-102).
2.Remove the duplex unit assembly
harness (page 8-100).
3.Connect J2750 of the duplex unit
assembly harness to P2750 of the
LVPS harness assembly.
4.Measure the voltage across P2750-
5 and J2750-6.
Does the voltage measure +3.3 VDC?
Go to step 4. Go to step 2.
2 Check the duplex unit detection signal
(2):
Measure the voltage across P/J27-4
and
P/J27-3 on the HVPS/engine logic
board.
Does the voltage measure +3.3 VDC?
Go to step 3. Replace the
HVPS/engine
logic board
(page 8-73).
3 Check the LVPS harness assembly:
1.Remove the duplex unit assembly
harness (page 8-100).
2.Check the following for continuity:
■ J27-4 <=> J2750-5
■ J27-3 <=> J2750-6
■ J27-2 <=> J2750-7
■ J27-1 <=> J2750-8
Is each continuous?
Go to step 4. Replace the
LVPS harness
assembly.