Panasonic UF-490 Service Manual page 85

4.4.5. Vertical Dark Lines
Is the printout in Service
Mode 3 normal?
Is the Toner Cartridge/
Drum Unit Assembly
operational?
Are there any foreign particles
or stains on the BTR?
Is the Laser Unit (LSU)
normal?
Are the Fuser and Pressure
Roller surfaces clean?
START
Yes
No
No
Yes
Yes
No
No
Yes
No
Yes
END
P
Check the Scanner mechanism.
Replace the Toner Cartridge/
Drum Unit Assembly.
1. Clean the BTR with a soft, dry
cloth.
2. Replace the BTR.
Replace the Laser Unit (LSU).
Clean or replace the rollers.
85