Brother HL1060 - B/W Laser Printer Service Manual page 71

I-3 Completely blank
Possible cause Step
Developing bias
contact failure
Drum unit
Drum unit failure
Scanner harness
connection failure
Main/Driver PCB
connection failure
Scanner unit
failure
Check
1 Are the developing bias
contacts between the printer
body and drum unit dirty?
2 Are the drum shaft and drum
electrode of the printer body
connected correctly?
3 Is the problem solved after the
drum unit is replaced?
4 Is the scanner harness
connected securely?
Is there any play in the
connection?
5 Are printing signals being input
to the scanner?
Is the problem solved after the
main PCB or the driver PCB
replaced?
6 Scanner interlock lever
damaged.
Scanner mirror is broken or
loose.
CHAPTER IV -7
Result Remedy
Yes Clean the electrodes
at both sides.
Yes Clean the shaft and
the electrode.
No Check the connection
between the shaft and
the electrode.
Yes Replace the drum
unit.
Yes Reconnect the
connector properly.
Yes Replace the main
PCB or the driver
PCB.
Yes Replace the scanner
unit.
No Replace the H.V.
power supply.
HV.GND
contacts
E
(Fig.4-5)
?
?