Oce 3121 Technical & Service Manual page 80

The copy is too light. (including solid black)
Cause
Transfer unit
(Transfer fault)
Paper
(Transfer fault)
Transfer guide
(Transfer fault)
High-voltage cable, high
voltage transformer, DC
control PBA
(Transfer fault)
ed.1
Step Checks
1 Carry out the image
adjustment procedure. Is
the problem corrected?
2 Switch OFF in the mid-
dle of the copying cycle.
Open the front door. Is
there a fairly normal
toner image on the OPC ?
3 Is the transfer unit prop-
erly installed?
4 Is there a leakage of
charge from the transfer
roller?
5 Is there dirt, cracks or
scratches on the transfer
roller?
6 Check the spring for the
transfer roller:- undam-
aged,- correct tension.
7 Using an alternative copy
paper, is the image
darker?
8 Position the feeding unit
in the operating position.
Measure the resistance
between the transfer
guide and the support of
the rail for the transfer
unit. Is the resistance 0
ohm?
Y/N Action
Yes End.
The image will be much
lighter if the pattern print
is placed in reverse
(left/right) orientation.
Ensure correct orienta-
tion of the test chart.
No Go to step 9
I
No Correctly fit the transfer
unit.
Yes Check the transfer unit.
Yes Replace the transfer
charging roller.
No Correct the position of
the spring, or replace the
spring.
Yes The paper may be
I
moist. Advise the user
regarding the correct
method of storing pa-
per.
Advise the user that the
I
use of non-recommend-
ed paper may reduce
the quality.
Yes Check the mechanical
connection of the metal
components (e.g. the side
plate of the feeding unit).
No Check the high-voltage
I
cable for electrical con-
tinuity.
Check the high voltage
I
transformer, and the
DC control PBA
Image quality 7