Printer Monocolor: Gradation Reproduction Failure - Konica Minolta Magicolor 8650 Service Manual

16. Image quality problem
16.3.6

Printer monocolor: gradation reproduction failure

A. Typical faulty images
B. Troubleshooting procedure
Step Section
Warning display
1
Photo/density
2
3 Imaging unit
PH unit
4
[Level History1]
on the list pro-
duced through
5 [Service Mode]
→ [List Output]
→ [Adjustment
List]
Service Mode →
ProcessAdjust-
6
ment → Dmax
Density
Service Mode →
ProcessAdjust-
ment → Stabili-
7
zarion →
Initialize + Stabi.
8
352
Confidential – for internal use only, do not distribute
Check item
The warning code is displayed on
the panel.
Original type and screen pattern are
selected properly.
Dirty on the outside.
The surface of the PH window is
dirty.
IDC output value is around 4.3 V.
The problem has been eliminated
through the adjust of Dmax Density.
After the Initialize + Stabi. sequence
has been completed, run gradation
adjust;
The problem has been eliminated
through the checks of steps up to 7.
Field Service Ver. 2.0 Nov. 2007
Result Action
YES Take action according to the
warning code shown on the
state confirm screen.
NO Change screen pattern.
YES Clean.
YES Clean with cleaning jig.
NO Clean IDC sensor and execute
the stabilization.
Check transfer belt for damage
and correct as necessary.
NO Go to next step.
NO Go to next step.
NO Change imaging unit.
→ Change printer control
board.
→ Change PH unit.
→ Change high voltage unit.
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