Color Spots - Konica Minolta BIZHUB C3100P Service Manual

1 Image Check
2
3 Transfer belt unit
4
5 Transfer roller
6
7 Paper path
8
9

5.2.12 Color spots

(1) Typical faulty images
The arrow in the exemplary image troubles indicates the paper feeding direction.
(2) Initial troubleshooting procedure
Step Section
1 IDC sensor
2 AIDC PROCESS
3 Secondarytransfer
4 Image check
(3) 1-color troubleshooting procedure
Step Section
1 Imaging unit
2
3
(4) 4-color troubleshooting procedure
Step Section
1 Transfer belt unit
2
3 Transfer roller
4 Paper path
5 Fusing unit
There are void areas at the front side or high density
section.
There is void area at the rear side section.
Fingerprints, oil, or other foreign matter is evident on the
transfer belt.
Transfer belt is dirty or scratched.
Transfer roller is dirty or scratched.
Charge neutralizing needle is not separated and ground
terminal is connected properly.
There is foreign matter on paper path.
Pre-image transfer guide plate is damaged or dirty.
The problem has been eliminated through the checks of
steps up to 8.
Check item
• IDC sensor is dirty.
• IDC sensor cover does not operate properly.
Select [Service Mode] -> [SYSTEM 2] -> [AIDC
PROCESS] and the image trouble is eliminated.
Select [Service Mode] -> [SYSTEM 2] -> [MEDIA
ADJUSTMENT] and the image trouble is eliminated.
* Decrease the setting value for color spots.
• Select [Service Mode] -> [PRINT MENU] ->
[HALFTONE 64]. Load tray with A4 paper. This runs a
print cycle for C, M, Y, and K in that order.
• Check the image after printing to determine which color
causes the abnormal image.
Check item for the faulty color
Developing bias contact terminal makes good connection.
The surface of the PC drum is scratched.
Dirty on the outside.
Check item
Fingerprints, oil, or other foreign matter is evident on the
image transfer belt.
Transfer belt is dirty or scratched.
Transfer roller is dirty or scratched.
There is foreign matter on paper path.
Fusing belt is dirty or scratched.
K TROUBLESHOOTING > 5. IMAGE QUALITY PROBLEM
YES
YES
YES
YES
YES
YES
YES
Result
YES
1 to 3
colors
colors
Result
YES
YES
Result
YES
YES
YES
YES
YES
K-33
K.7.2.6 Faint image, low image
density (ID lowering)
Make the following adjustment:
[Service Mode] -> [SYSTEM 2] ->
[MEDIA ADJUSTMENT].
Clean it with the tender cloth or paper
which is dusted with the toner.
• Clean dirty belt with a soft cloth.
• Replace the transfer belt unit
is damaged.
Replace the transfer roller.
NO Correct or change.
Remove foreign matter.
Clean or change.
NO Replace the transfer belt unit.
Action
• Clean.
• Clean or correct the IDC sensor
cover.
NO Go to the next step.
NO Return the setting value to the original
one and go to the next step.
Go to the 1-color troubleshooting
procedure.
4 Go to the 4-color troubleshooting
procedure.
Action
NO Clean contact terminal and check
terminal position.
Replace the imaging unit.
Clean.
Action
Clean it with the tender cloth or paper
which is dusted with the toner.
• Clean dirty belt with a soft cloth.
• Replace the transfer belt unit
is damaged.
Replace the transfer roller.
Remove foreign matter.
Replace the fusing unit.
if belt
if belt