Printer 4-Color: Low Image Density - Konica Minolta bizhub C250 Service Manual

18. Image quality problem
18.3.30

Printer 4-Color: low image density

A. Typical Faulty Images
B. Troubleshooting Procedure
Step Section
Paper
1
Image Transfer Belt
2
Unit
2nd Image Transfer
3
Roller Unit
4
5 IDC Sensor
Image Process
Adjustment → Grada-
6 tion Adjust
(Service Mode)
Image Process
Adjustment → D Max
7
Density
(Service Mode)
Image Process
Adjustment → Stabi-
8
lizer → Reset + Stabi-
lizer (Service Mode)
9
508
ABCDE
ABCDE
ABCDE
ABCDE
ABCDE
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Check Item
Paper is damp.
Terminal is dirty.
Image Transfer Roller is installed
properly.
Image Transfer Roller is dirty or
scratched.
Sensor is dirty.
"Conv. Value" falls within the speci-
fied range as checked through Gra-
dation Adjust.
Max: 0 ± 100
Highlight: 0 ± 60
The problem has been eliminated
through the adjust of D Max Den-
sity.
After the Reset + Stabilizer
sequence has been completed, run
Gradation Adjust.
The problem has been eliminated
through the checks of steps up to 8.
Field Service Ver. 3.0 Aug. 2006
Result Action
YES Change paper to one just
unwrapped from its pack-
age. Install Paper Dehu-
midifying Heater.
YES Clean.
NO Reinstall.
NO Change 2nd Image Trans-
fer Roller Unit.
YES Clean with blower brush.
YES Go to step 9.
NO Go to next step.
NO Go to next step.
NO Change Image Transfer
Belt Unit.
→ Change MFP Control
Board.
→ Change High Voltage
Unit (Image Transfer,
Neutralizing).