Oce 3121 Technical & Service Manual page 86

The copy has white spots (horizontal).
Cause
Developing unit
Developing unit
OPC unit
Paper
Transfer unit
Developing bias
The scanning rail, and
the scanner cable
ed.1
Step Checks
1 Execute ( ' * 4 * ' ) , '
L-TEET1 ' in service
mode. Are there white
lines in the resulting
image?
2 Is the problem repeated
at intervals of approxi-
mately 35 mm?
3 Is the problem repeated
at intervals of approxi-
mately 94 mm?
4 Using an alternative copy
paper, is the image
darker?
5 Are there white spots on
the photosensitive drum
during copying?
6 Are there white spots on
the photosensitive drum
during copying?
7 Is the problem repeated
at the same location on
every copy?
Y/N Action
Yes Go to step 4.
Yes Clean the developing
I
roller.
Wipe the surface of the
I
developing roller, until
it is dry.
If scratches are found
I
on the developing cyl-
inder, replace the devel-
oping unit.
Yes Clean the OPC.
I
If there are scratches,
I
replace the OPC unit.
Yes The paper may be moist.
Advise the user regarding
the correct method of
storing paper.
No Check the transfer unit
assembly for leakage.
Yes Check the developing
bias.
Yes Check the scanner rail
I
for foreign matter.
Adjust the tension of
I
the scanner cable.
Image quality 13