White Spot - Konica Minolta bizhub PRO C6501 Troubleshooting Manual

2 White spot

[Symptom]
White spot appears on the image.
Spot with core
A: When symptom occurs only for single color, see probable cause A.
B: If the symptom is solved when changing the paper type to the recommended paper, see
probable cause B.
[Probable causes and solutions]
A: If the spot has core, white spot appears due to the increase of the inside machine
temperature according to the high room temperature or other factor. By the temperature
increase, toner forms core in the developer and the poor transfer (1
occurs around the core, causing the white spots.
If the spot does not have core, the cause is the high charge developer by the many prints
of the low coverage original etc. When the charge amount of the developer increases,
the transfer ability decreases at the part, causing white spots.
To correct the above, perform toner refresh mode:
Utility menu => [03 Machine Admin. Setting] => [01 System Setting] => [05 Expert
Adjustment] => [08 Execute Adjust Operation] => [Toner refresh mode]
If it does not improve, after checking the following setting, perform the toner refresh mode
again.
Service mode => [02 Process adjustment] => [05 Interval/Quantity adjustment] => [03
Auto refresh interval] => [Refresh quantity] => Select from [small], [middle], [large]
Refresh amount
Small
Middle
Large
If toner refresh is performed excessively, not only too much toner is consumed but may
cause cleaning failure of the transfer belt (passing through, packing). Therefore, keep the
above max number when performing the refresh mode.
B: If the used paper and the set current for the 1
transfer ability becomes poor and tends to generates white spots. To correct the above,
st
perform 1 transfer manual adjustment and 2
adjustment procedure, see
Table of contents
Toner consumption per one
refresh operation
A3 solid, 3 sheets equivalent
A3 solid, 5 sheets equivalent
A3 solid, 8 sheets equivalent
(8050 equivalent)
13 Problem with non-recommended
4
Spot without core
Max number for refresh
mode execution
3 times
Twice
Once
st nd
transfer and the 2
nd
transfer manual adjustment. For the
paper.
st nd
transfer/2 transfer)
transfer do not match,