Printer Monocolor: Foggy Background - Olivetti d-Color MF651 Service Manual

22. IMAGE QUALITY PROBLEM
22.3.21

Printer monocolor: foggy background

A. Typical faulty images
B. Troubleshooting procedure
Step Section
1 Warning display
2 State Confirma-
tion Table
Number
(Service Mode)
3 State Confirma-
tion Level His-
tory 1
4
(Service Mode)
5 Level history data
check results
6
7
8
9
10 Imaging unit
11 PH unit
12 Image Process
Adjustment
Background Volt-
age Margin
(Service Mode)
884
ABCD
ABCD
ABCD
ABCD
ABCD
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.
The problem is eliminated after
background voltage margin has
been adjusted.
Service Manual
Field Service Ver. 2.0 Jul. 2009
A02EF4C510DA
Result Action
YES Take action according to the
warning code shown on the
state confirm screen.
NO Go to next step.
NO Go to next step.
NO Clean IDC sensor and execute
the image stabilization.
Check image transfer belt for
damage and correct as neces-
sary.
YES Go to step 10.
YES Go to step 12.
YES Go to step 10.
YES Go to step 12.
YES Go to step 10.
YES Clean.
YES Clean with cleaning jig.
NO Go to next step.
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