19. Image quality problem
Field Service Ver. 1.0 Jun. 2008
354
T
roubleshooting
19.3.31
Printer 4-color: low image density
A. Typical faulty images
B. Troubleshooting procedure
A02EF4C516DA
ABCDE
ABCDE
ABCDE
ABCDE
ABCDE
Step
Section
Check item
Result
Action
1
Paper
Paper is damp.
YES
Change paper to one just
unwrapped from its package.
2
Transfer belt unit
Terminal is dirty.
YES
Clean.
3
Transfer roller
unit
Transfer roller is installed properly.
NO
Reinstall.
4
Transfer roller is dirty or scratched.
NO
Change transfer roller unit.
5
IDC sensor
Sensor is dirty.
YES
Clean IDC sensor and execute
the image stabilization.
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
Density.
NO
Go to next step.
8
Image Process
Adjustment
o
Image Stabiliza-
tion
o
Init
Image Stabiliza-
tion
(Service Mode)
After the Init Image Stabili-
zation sequence has been com-
pleted, run gradation adjust.
NO
Go to next step.
9
The problem has been eliminated
through the checks of steps up to 8.
NO
Change image transfer belt unit.
o
Change printer control board
o
Change high voltage unit.
d-Color MF201
Service Manual Y109660-1
