Brother HL-1040 - Manual (Page 73)

IV-6
I-2 Dark
Possible cause Step Check Result Remedy HV.GND
contacts
(Fig.4-5)
Corona failure
(soiled wire) 1 Is the corona wire dirty? Yes Clean the corona wire
by using the wire
cleaner.
➇
Corona failure
(contact failure) 2 Are the corona electrodes
between the printer body and
drum unit dirty? No Clean both electrodes.
➅
Drum unit failure 3 Is the problem solved when the
drum unit is replaced? Yes Replace the drum
unit with a new one.
High-voltage
power supply
PCB 4 Are there any disconnected
connectors? No Replace the high-
voltage power supply
PCB.
Main PCB 5 Are there any disconnected
connectors? No Replace the main
PCB.
Panel sensor
PCB 6 Are there any disconnected
connectors? No Replace the panel
sensor PCB.