3-26 Phaser 4500 Service Manual
Main Motor Failure
Error Code
U1: Main Drive Motor Failure
Troubleshooting Reference
Applicable Parts Wiring and Plug/Jack Map References
■ Main Motor
■ Gear Assembly Housing
■ Plate Gear Assembly
■ LVPS
■ HVPS/Engine Logic Board
■ “24 V Interlock, Rear Cover Switch, Main Motor, Sub
Fan, Exit Motor Assembly” on page 10-18
■ “Laser Unit, 5 V Interlock, Interlock Switch
Assembly” on page 10-24
■ “Print Engine General Wiring Diagram” on
page 10-17
■ “Print Engine Plug/Jack Locator” on page 10-3
Troubleshooting Procedure
Steps Actions and Questions Yes No
1
1. Remove the Left Cover (page 8-9).
2. Enter Service Diagnostics and check
Main Motor operation.
Does the Main Motor rotate, and each
gear rotate normally?
Replace the
HVPS/Engine
Logic Board.
(page 8-89)
Go to step 2.
2
Rotate and check each gear of the Gear
Assembly Housing and Plate Gear
Assembly.
Does each gear rotate normally?
Go to Main Motor
(page 4-11).
Replace the parts
causing the
obstruction.