Brother HL-1040 - Manual (Page 75)

IV-8
I-4 All black
Possible cause Step Check Result Remedy HV.GND
contacts
(Fig.4-5)
Corona failure 1 Is the corona wire of the drum
unit broken? Yes Replace the drum
unit.
2 Are the electric terminal
springs in the printer body and
the electrode on the bottom
face of the drum unit dirty? Yes Clean the terminals
in the printer and on
the drum.
➅
Harness
connection 3 Is the scanner unit connected
with the panel sensor PCB
correctly? No Check the harness
connection between
the scanner unit and
the panel sensor
PCB.
High-voltage
power supply
PCB 4 Is the problem solved after
high-voltage power supply
PCB replaced? Yes Replace the high-
voltage power supply
PCB.
Ditto 5 Perform the same check as in
step 3. Yes Replace the panel
sensor PCB.
Main PCB 6 Is the problem solved after
main PCB is replaced? Yes Replace the main
PCB.
Panel sensor
PCB 7 Is the problem solved after the
panel sensor PCB is replaced? Yes Replace the panel
sensor PCB.