Brother HL-1040 - Manual (Page 74)

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