Printer Monocolor: Uneven Density In Sub Scan Direction - Konica Minolta bizhub C200 Service Manual

19. Image quality problem
19.3.17

Printer monocolor: uneven density in sub scan direction

A. Typical faulty images
B. Troubleshooting procedure
Step Section
High image
density original
1
Imaging unit
2
3
PH unit
4
Image transfer
5
belt unit
6
392
Check item
Uneven density in sub scan direc-
tion occurs at a pitch of 40 mm to
50 mm when a multi-copy cycle is
run using an original with high
image density (50% or more).
The surface of the PC drum is
scratched.
Dirty on the outside.
The surface of the PH window is
dirty.
Is abnormality found in the cam
gear?
The problem has been eliminated
through the checks of steps up to 5.
Field Service Ver. 2.0 Dec. 2008
Result Action
YES Feed 10 to 20 blank sheets of
paper with no originals placed, as
the IU fails to keep up with a high
demand for toner.
YES Change imaging unit.
YES Clean.
YES Clean with cleaning jig.
YES Change transfer belt unit.
NO Change IU.
→ Change PH unit.
→ Change printer control board
→ Change high voltage unit.
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