Brother HL-4040CN - Image Distortion

Confidential
1-45
Completely blank
User Check
- Replace the toner cartridge or drum unit with a new one.
Step Cause
Check Result Remedy
1 Developing bias
voltage
conduction failure
Are the electrodes on the
drum unit and machine
body dirty?
Yes Clean both electrodes.
2 Scanner harness
connection failure
Is the scanner harness
connected securely?
No Reconnect the scanner
harness.
3 Engine PCB
failure
Is the problem solved
after replacing the engine
PCB ASSY?
Yes Replace the engine PCB
ASSY.
4 Laser unit failure Is the problem solved
after replacing the Laser
unit?
Yes Replace the laser unit.
5 Transfer HVPS
PCB failure
Is the problem solved
after replacing the
transfer HVPS PCB
ASSY?
Yes Replace the transfer
HVPS PCB ASSY.
6 Charge HVPS
PCB failure
Is the problem solved
after replacing the charge
HVPS PCB ASSY?
Yes Replace the charge
HVPS PCB ASSY.
Image distortion
Step Cause
Check Result Remedy
1 Laser unit not
assembled
correctly
Is the laser unit
assembled into the
machine securely?
(Check if there is no gap.)
No Assemble the laser unit
correctly and secure the
screw.
2 Incorrect radiation
angle of scanner
diode
Scanner motor
rotation failure
Is the problem solved
after replacing the laser
unit?
Yes Replace the laser unit.