Image Distortion; All Black; Dirt On The Back Of Paper - Brother HL-2250DN Service Manual

4.2.6 Image distortion

Step
Laser unit not assembled correctly
1
2 Laser unit failure
3 Main PCB failure

4.2.7 All black

Step
Dirt on drum unit and printer body
1
electrodes
Scanner harness of the laser unit
2
connection failure
FG plate connection failure
3
High voltage power supply PCB
4
ASSY failure
5 Main PCB failure
6 Laser unit failure

4.2.8 Dirt on the back of paper

Step
1 Dirt on the fuser unit
2 Dirt in the paper feed system
Cause
User Check
• Clean the corona wire of drum unit.
• Replace the drum unit with a new one.
Cause
User Check
• This problem may disappear after printing approximately
10 pages of completely blank sheets.
Cause
2-33
Remedy
Assemble the laser unit correctly and
secure the screw.
Replace the laser unit.
Replace the main PCB ASSY.
Remedy
Clean the electrodes of the drum unit and
printer body. (Refer to Fig. 2-8, Fig.
Reconnect the scanner harness of the
laser unit.
Reconnect the FG plate between the laser
unit and develop drive sub ASSY securely,
and secure the screw.
Replace the high voltage power supply
PCB ASSY.
Replace the main PCB ASSY.
Replace the laser unit.
Remedy
Replace the fuser unit.
Wipe dirt off.
2-9.)
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