Toshiba DP4500 Service Handbook page 203

(14) White spots
Defective area
Developer unit/
Toner cartridge
Doctor-sleeve gap
Main charger
High-voltage transformer
(main charger/ developer
bias/transfer charger)
Transfer/Separation
charger
Developer material
DP4500/3500 TROUBLESHOOTING
Step Check Items
1 Is the toner density in the developer ma-
terial appropriate?
2 Is the doctor-sleeve gap proper?
3 Is there any foreign object on the charger?
4 Is the charger wire dirty or deformed?
5 Is the output from the high-voltage trans-
former normal?
6 Is there any object such as fiber in the
paper transport area of the transfer/sepa-
ration charger?
7 Has the developer material reached its
PM life?
Check and correct the auto-toner sensor and toner
supply operation.
Check if the amount of the toner is sufficient in the
toner cartridge.
Adjust it.
Remove it.
Clean or replace the charger wire.
Adjust the output.
Clean the charger.
Replace the developer material.
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Prescription
December 2000 © TOSHIBA TEC