IV - 5
Possible cause
Step
Check
Result
Remedy
Contrast
failure
1
Is the contrast adjustment dial at
the center click position?
No
Set it to the center click
position or reasonable
position.
Corona failure
(soiled wire)
2
Is the corona wire soiled?
Yes
Clean the corona wire.
Corona failure
(contact failure)
3
Are the corona electrodes between the printer
body (bottom plate spring) and drum unit
soiled?
Is the bottom plate spring normal?
No
Clean both electrodes.
If the spring is abnormal,
replace it.
Drum unit failure
4
Is the problem solved when the drum unit is
replaced?
Yes
Replace the drum unit with
a new one.
I-2
Dark
Possible cause
Step
Check
Result
Remedy
Developing bias
contact failure
1
Are the developing bias contacts between the
printer body and drum unit soild ?
Yes
Clean the electrodes at
both sides.
Scanner harness
connection failure
2
Is the scanner LD controlharness connected
normally?
Is there any play in the connection?
Yes
Connect the connector
correctly.
Main/driver PCB
connection failure
3
Are printing signals being input to the scanner?
No
Replace the main PCB or
driver PCB.
Completely blank
I-3