Olivetti d-color MF651, Service Manual, Page: 941 / 1053

Field Service Ver. 2.0 Jul. 2009 22. IMAGE QUALITY PROBLEM
881
TROUBLESHOOTING
22.3.19 Printer monocolor: low image density
A. Typical faulty images
B. Troubleshooting procedure
A02EF4C516DA
ABCDE
ABCDE
ABCDE
ABCDE
ABCDE
Step Section Check item Result Action
1 Warning display The maintenance call mark is
displayed on the panel. YES Take action according to the
warning code shown on the
state confirm screen.
2 State Confirm
o
Table Number
(Service Mode)
Check data for Vg and Vdc.
Color
Vdc: around 400 V
Vg : around 500 V
Black Vdc: around 400 V
Vg : around 500 V

Go to next step.
3 State Confirma-
tion
o
Level His-
tory 1
(Service Mode)
Check TCR data.
(specified rang: 6 to 8 %) NO Go to next step.
4 IDC output value is around 4.3 V. NO Clean IDC sensor and exe-
cute the image stabilization.
Check image transfer belt for
damage and correct as nec-
essary.
5 Level history data
check results Low TCR and low Vg and Vdc YES Go to step 10.
6 Low TCR and high Vg and Vdc YES Go to step 14.
7 TCR falling within specified range
and low Vg and Vdc YES Go to step 10.
8 TCR falling within specified range
and high Vg and Vdc YES Go to step 14.
9 The situations other than the above-
mentioned. YES Go to step 10.
10 Imaging unit Dirty on the outside. YES Clean.
11 PH unit The surface of the PH window is
dirty. YES Clean with cleaning jig.
12 Transfer belt unit Transfer belt unit makes positive
contact with plates on rails. NO Check and correct contacts.
13 Is abnormality found in the cam
gear? YES Change image transfer belt
unit.
Y110571-1 Service Manual