Brother MFC-7240 - Image Distortion

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