Printer Monocolor: Low Image Density - Konica Minolta bizhub C200 Service Manual

19. Image quality problem
19.3.19

Printer monocolor: low image density

A. Typical faulty images
B. Troubleshooting procedure
Step Section
Warning display
1
State Confirma-
tion → Table Num-
2 ber
(Service Mode)
State Confirma-
3
tion → Level His-
tory 1
(Service Mode)
4
5 Level history data
check results
6
7
8
9
10 Imaging unit
PH unit
11
Transfer belt unit
12
13
394
ABCDE
ABCDE
ABCDE
ABCDE
ABCDE
Check item
The maintenance call mark is
displayed on the panel.
Check data for Vg and Vdc.
Color Vdc: around 400 V
Vg : around 500 V
Black Vdc: around 400 V
Vg : around 500 V
Check TCR data.
(specified rang: 6 to 8 %)
IDC output value is around 4.3 V.
Low TCR and low Vg and Vdc
Low TCR and high Vg and Vdc
TCR falling within specified range
and low Vg and Vdc
TCR falling within specified range
and high Vg and Vdc
The situations other than the above-
mentioned.
Dirty on the outside.
The surface of the PH window is
dirty.
Transfer belt unit makes positive
contact with plates on rails.
Is abnormality found in the cam
gear?
Field Service Ver. 2.0 Dec. 2008
A02EF4C516DA
Result Action
YES Take action according to the
warning code shown on the
state confirm screen.
⎯
Go to next step.
NO Go to next step.
NO Clean IDC sensor and exe-
cute the image stabilization.
Check image transfer belt for
damage and correct as nec-
essary.
YES Go to step 10.
YES Go to step 14.
YES Go to step 10.
YES Go to step 14.
YES Go to step 10.
YES Clean.
YES Clean with cleaning jig.
NO Check and correct contacts.
YES Change transfer belt unit.