19. Image quality problem
Field Service Ver. 1.0 Jun. 2008
342
T
roubleshooting
19.3.20
Printer monocolor: gradation reproduction failure
A. Typical faulty images
B. Troubleshooting procedure
A02EF4C522DA
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
Photo/density
Original type and screen pattern are
selected properly.
NO
Change screen pattern.
3
Imaging unit
Dirty on the outside.
YES
Clean.
4
PH unit
The surface of the PH window is
dirty.
YES
Clean with cleaning jig.
5
State Confirma-
tion
o
Level His-
tory 1
(Service Mode)
IDC output value is around 4.3 V.
NO
Clean IDC sensor and execute
the image stabilization.
Check transfer belt for damage
and correct as necessary.
6
Image Process
Adjustment
o
Gradation
Adjust
(Service Mode)
“Conv. Value” falls within the
specified range as checked through
gradation adjust.
Dark: 0 ± 100
Highlight: 0 ± 60
YES
Go to step 9.
7
Image Process
Adjustment
o
D Max Density
(Service Mode)
The problem has been eliminated
through the adjust of D Max.
NO
Go to next step.
8
Image Process
Adjustment
o
Image Stabili-
zation
o
Initial-
ize + Image
Stabilization
(Service Mode)
After the Init Image Stabiliza-
tion sequence has been completed,
run gradation adjust;
NO
Go to next step.
9
The problem has been eliminated
through the checks of steps up to 8.
NO
Change imaging unit.
o
Change printer control board
o
Change PH unit.
o
Change high voltage unit.
d-Color MF201
Service Manual Y109660-1
