Konica Minolta BIZHUB 25E Field Engineering Manual page 230

4.5.5 Dark image density
Scanner section
Section Step Check item
Scanner section 1
2
3
4
5
Printer section
Section Step Check item
Drum cartridge 1
2
Circuit boards 3
4
Are the ADF glass and document
glass dirty?
Are the CIS (lens and lamp) and
document glass dirty?
Is the CIS installed properly?
Do the connection from CIS to main
control board remain intact?
Is the trouble settled with above
steps?
Are the developing bias, supply bias
and blade bias contact terminal dirty
or deformed?
Are the grid bias, charge bias and
drum ground contact terminal dirty or
deformed?
Are the connections from LED print
head and from high-voltage board to
main control board in good condition?
(Check plugs firmly plugged and
snapped harness.)
Is the trouble settled with above
steps?
Result Remedy
Yes Clean
Yes Clean
No Install it properly
No Reconnect / Replace harness.
No 1. Adjust the background level.
2. Replace CIS.
3. Replace main control board.
Result Remedy
Yes Clean / Repair
Yes Clean / Repair
No Reconnect / Replace harness
No 1. Replace drum cartridge.
2. Replace LED print head.
3. Replace main control board.
4. Replace high-voltage power
board.
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