Toshiba DP4500 Service Handbook page 201

(12) Black banding (in the feeding direction)
Defective area
Scanner
Main charger grid
Main charger
Cleaner
Fuser unit
Drum
Laser optical unit
Shading correction plate
DP4500/3500 TROUBLESHOOTING
Step Check Items
1 Is there a foreign object on the light path?
2 Is there a foreign object on the grid?
3 Is the grid dirty or deformed?
4 Is there a foreign object on the main
charger?
5 Is the charger wire dirty or deformed?
6 Is there a foreign object inside the charger
case?
7 Is inside the charger case dirty?
8 Is there paper dust or something sticking
to the cleaning blade edge?
9 Is the cleaning blade working properly?
10 Has the used toner been recovered properly?
11 (1) Is the fuser roller surface dirty or dam-
aged?
(2) Is the thermistor cleaned at the pre-
ventive maintenance?
12 Are there scratches on the drum surface?
13 Is there a foreign object or stain on the slit
glass?
14 Is there dust or stains on part of the original
glass where the shading correction plate
is placed on top.
Clean the lens and mirrors.
Remove the foreign object.
Clean or replace the grid.
Remove the foreign object.
Clean or replace the charger wire.
Remove the foreign object.
Clean inside the case.
Clean or replace the cleaning blade.
Check the pressurization of the drum cleaning
blade.
Clean the toner recovery auger.
(1) Clean or replace the fuser roller.
(2) Clean the thermistor.
Replace the drum.
Remove the foreign object or the stain.
Clean the plate.
5 - 106
Prescription
December 2000 © TOSHIBA TEC