Image Quality Problems; Printer System; White Lines/Bands, Colored Lines/Bands In Sub Scan Direction - Konica Minolta bizhub c20 Service Manual

Field Service Ver. 1.0 Sep. 2008

20. Image quality problems

20.1 Printer system

NOTE
• Typical faulty image samples shown in the following are all printed with A4S set-
ting.
20.1.1

White lines/bands, colored lines/bands in sub scan direction

A. Typical faulty images
white lines in
sub scan direction
B. Troubleshooting procedure
Step Section
1
2
Imaging unit
3
4
5 PH unit
6
Transfer belt unit
7
8 Transfer roller
9 Paper path
10
Fuser unit
11
12
white bands in
sub scan direction
Check item
Are there scratches or lines evi-
dent on photo conductor surface?
Is the outside dirty?
Is the connector or contact termi-
nal between each imaging unit
and PH unit connected properly?
Is the developing bias contact ter-
minal in good contact?
Is the window surface dirty?
Is the transfer belt dirty with fin-
gerprints or oil?
Is the transfer belt dirty or
scratched?
Is the transfer roller dirty or
scratched?
Is there a foreign matter on the
paper path?
Is the fusing entrance guide plate
dirty or scratched?
Is the separator fingers dirty?
Has the problem been eliminated
through the checks of steps up to
11?
20. Image quality problems
colored lines in colored bands in
sub scan direction sub scan direction
Result
YES Change the imaging unit.
YES Clean.
Clean the contact terminal or
NO
reconnect the connector.
Clean the contact terminal or
NO
check the terminal position.
YES Clean.
YES Clean.
Wipe the surface clean of dirt with
YES a soft cloth. Change a scratched
transfer belt for a transfer belt.
YES Change the transfer roller.
YES Remove foreign matter.
Clean.
YES
Change the fuser unit.
YES Change the fuser unit.
Change the transfer belt unit.
NO
Change the PH unit.
A0CRF4C503DA
Action
353