4-54 Phaser 4500 Service Manual
Duplex Unit PWBA
Troubleshooting Reference
Applicable Parts Wiring and Plug/Jack Map References
■ Duplex Unit PWBA
■ Duplex Unit Assembly Harness
■ HVPS/Engine Logic Board
■ LVPS Harness Assembly
■ “Duplex Unit Signal Diagram” on page 10-30
■ “Duplex Unit General Wiring Diagram” on
page 10-29
■ “Duplex Unit Plug/Jack Locator” on page 10-12
Troubleshooting Procedure
Steps Actions and Questions Yes No
1 Check the Duplex Unit Assembly Harness:
1. Remove the Duplex Unit.
2. Disconnect P/J50 from the Duplex Unit
PWBA.
3. Test each cable between J2750 <=> J50
for continuity.
Is each cable continuous?
Go to step 2. Replace the
Duplex Unit
Assembly
Harness.
2 Check the LVPS Harness Assembly:
1. Disconnect P/J27 from the HVPS/
Engine Logic Board.
2. Test each cable between J27 <=> J2750
for continuity.
Is each cable continuous?
Go to step 3. Replace the
LVPS Harness
Assembly.
3 Replace the Duplex Unit PWBA
(page 8-123).
Is the problem cleared after
replacement?
Problem solved. Replace the
HVPS/Engine
Logic Board
(page 8-89).