Image Distortion - Brother FAX-2840 Service Manual

Image distortion

Step
1 Laser unit attachment failure
2 Laser unit failure
3 Main PCB failure
All black
<User Check>
- Clean the corona wire of the drum unit.
- Replace the drum unit with a new one.
Step
Dirt on electrodes of the drum unit
1 and those of the machine
Connection failure of the scanner
2
harness of the laser unit
Earth plate connection failure
3
High voltage power supply PCB
4
failure
5 Laser unit failure
6 Main PCB failure
Dirt on the back of paper
Step
1 Dirt on the fuser unit
2 Dirt in the paper feed system
Cause
Attach the laser unit correctly and secure the screw.
Replace the laser unit.
Replace the main PCB ASSY.
Cause
Clean the electrodes of the drum unit and
those of the machine. (Refer to
and
Reconnect the scanner harness of the laser
unit.
Reconnect the earth 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 laser unit.
Replace the main PCB ASSY.
<User Check>
- This problem may disappear after printing
approximately 10 pages of completely blank sheets.
Cause
2-69
Remedy
Remedy
Fig. 2-11.)
Remedy
Replace the fuser unit.
Wipe off the dirt.
Fig. 2-10
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