Toshiba DP4500 Service Handbook page 202

(13) Black banding (at right angle with the feeding direction)
Defective area Step
Main charger wire 1
Fuser roller, separation 2
finger and thermistor
Cleaning roller for 3
pressure roller
High-voltage transformer 4
(main charger/
transfer charger)
Drum 5
6
Scanner carriage 7
December 2000 © TOSHIBA TEC
Check Items
Is the charger wire dirty or deformed?
Are the fuser roller, separation finger and
thermistor dirty?
Has the cleaning roller for the pressure
roller reached its PM life?
Is the output from the high-voltage trans-
former normal?
Is there a deep scratch on the drum sur-
face?
Are there thin scratches (drum pitting) on
the drum surface?
Is there a foreign object on the carriage
rail?
5 - 107
Prescription
Clean or replace the charger wire.
Clean them.
Replace it.
Check the circuit and replace the high-voltage
transformer if it is defective.
Replace the drum if the scratch has reached the
aluminum base.
Check and adjust the contact condition of the
cleaning blade and recovery blade.
Remove the foreign object.
DP4500/3500 TROUBLESHOOTING