Abnormal Image - Konica Minolta bizhub PRO C6501 Troubleshooting Manual

31 Abnormal Image

[Symptom]
During printing multiple sets of a job, the abnormal image as shown in below suddenly appears
and it continues until the end of job.
=> When power switch of main body is turned OFF/ON, the machine returns to the normal
printing.
- Negative-positive reversed like image
- Like the posterlization applied image with the abnormal gradation
- Colored background
[Probable cause]
- Noise on the communication between controller and main body is the cause.
Possible factors for noise occurrence are multiple.
1) Connection failure between main body, controller, I/F board and cables.
2) Device operation clock switch during data communication
[Solution]
Noise occurrence factor is not just one. Therefore, it is necessary to classify the cause and to
take appropriate solution. Check following points
1. Is main body and controller connected properly?
=> Check individual cable problem by replacing cable.
2. Is pull-up register (R144) of C6500/C5500 Image Processing Board (A03UH02015)
removed type?
* Subject is C6500/C5500 only.
3. Is pull-up register on controller I/F board removed?
If the subject pull-up register is installed, remove it.
IC-303/305/408 => R7401
IC-305 => R127
[CAUTION]
*
On C6501/C5501 image processing board, the device has been changed.
Therefore, DO NOT remove register.
Table of contents
R7401
43
R127