Oce 3121 Technical & Service Manual page 90

The copy has horizontal lines of background
Cause
Scanning lamp, power
supply PBA
Developing unit
Scanner
OPC drive
OPC unit
The copy is not sharp
Cause
Platen
Scanner (dirty)
Position of the mirror
Developing bias
OPC unit, the transfer
system
ed.1
Step Checks
1 Is the location of the
problem area on the copy
consistent for all copies
made in direct mode?
2 Does the scanning lamp
flicker while the scanner
is moving?
3 Is there an even coating
of toner on the develop-
ing roller?
4 Make reduced size cop-
ies. Compare the copies
with the copies made in
direct mode. Has the
location of the problem
changed?
Step Checks
1 Is a printed photo (with
raster pattern) copied in
photo mode?
2 Is there oil on the platen? Yes Clean the platen
3 Clean the scanning lamp,
the exposure reference
strip, the mirror, the lens
and the exposure aper-
ture.
4 Is the horizontal repro-
duction ratio within the
specified range, in direct
mode?
5 Is the developing bias
generated correctly?
6 Replace the OPC unit. Is
the problem corrected?
Y/N Action
Yes Go to step 4
Yes Check the scanning lamp
and the power supply
PBA (lamp ON circuit),
and the 2.4V power sup-
ply.
No Check the developing
bias.
Yes Check the scanning sys-
tem
No Check the feeding system
Y/N Action
Yes Advise the user that
moiré may occur at
times.
No Adjust the distance
between the mirror 1 and
the mirror 2.
No Replace the power sup-
I
ply PBA
Replace the DC control
I
PBA
No Check the transfer sys-
tem
Image quality 17