Monocolor: Uneven Density In Sub Scan Direction - Konica Minolta magicolor 7450 Service Manual

Field Service Ver. 1.0 May 2006
16.3.3

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
5 Transfer Belt
6
4036fs4043c0
Check Item
Uneven density in Sub Scan Direc-
tion occurs at a pitch of 40 mm to
50 mm when a multi-print 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.
Cam gear operates properly.
The problem has been eliminated
through the checks of steps up to 5.
16. Image quality problem
4036fs4044c0 4036fs4045c0
Result
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.
NO Change Transfer Belt.
NO Change IU.
→ Change PH Unit.
→ Change Controller Board.
→ Change High Voltage Unit
(Image Transfer, Neutralizing).
Action
217