Printer System: Foggy Background - Konica Minolta bizhub 250 Service Manual

21. Image quality problem
21.3.10

Printer System: Foggy background

A. Typical Faulty Images
B. Troubleshooting Procedure
Step Section
1 -
2 Imaging Unit
3
4
5
6 Erase Lamp
7
8 Tech. Rep. Mode
→ Image Den-
sity
9 Tech. Rep. Mode
→ Grid Voltage
Adjustment
10 -
262
EDNord - Istedgade 37A - 9000 Aalborg - telefon 96333500
ABCD
ABCD
ABCD
ABCD
ABCD
Check Item
Sunlight or any other extraneous light
enters the machine.
Photo Conductor is dirty.
Comb Electrode contact terminal is dirty
or deformed.
Grid voltage contact terminal is dirty or
deformed.
Charge Neutralizing Sheet contact ter-
minal is dirty or deformed.
Erase Lamp is dirty.
Is there continuity across the Erase
Lamp?
Select Tech. Rep. Mode → [Tech. Rep.
Choice] → [Printer] → [Image Density].
The image problem can be corrected by
selecting an Image Density setting
toward the - end.
Select Tech. Rep. Mode → [Tech. Rep.
Choice] → [Printer] → [Grid Voltage
Adjustment].
The image problem can be corrected by
selecting an VG Adjust setting toward
the - end.
The problem has been eliminated after
performing step 9.
Field Service Ver. 1.0 Aug. 2005
4036fs4030c0
Result
YES Protect the copier from
extraneous light.
YES Change Photo Conductor
Unit.
YES Clean.
Change Photo Conductor
Unit.
YES Clean.
Change Photo Conductor
Unit.
YES Clean.
Change Photo Conductor
Unit.
YES Clean.
NO Change Erase Lamp.
YES Make setting again.
YES Make setting again.
NO Change Photo Conductor
Unit.
Change Developing Unit.
Change PH Unit.
Change High Voltage
Unit.
Change Mechanical Con-
trol Board.
Action