Brother HL-L5000D Service Manual page 128

 Image distortion
Step
1 Laser unit attachment failure
2 Laser unit failure
3 Main PCB failure
 All black
Step
Dirt on the electrodes of the drum
1 unit and those of the machine
2 Laser unit flat cable failure
Dirt on the electrodes of the
3
machine
High-voltage power supply PCB
4
failure
5 Laser unit failure
6 Main PCB failure
Cause
<User Check>
- Clean the corona wire of the drum unit.
- Replace the drum unit with a new one.
Cause
2-102
Remedy
Reattach the laser unit.
Replace the laser unit.
Replace the main PCB ASSY.
Remedy
Clean the electrodes of the drum unit and
those of the machine. (Refer to
Fig. 2-7.)
Replace the laser unit flat cable.
Clean the electrodes of the machine.
(Refer to Fig. 2-7.)
Replace the high-voltage power supply PCB
ASSY.
Replace the laser unit.
Replace the main PCB ASSY.
Fig. 2-6 and
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