Brother MFC-7450

1-41
Confidential
■ Downward fogging of solid color
■ Horizontal lines
User Check
• Toner may be empty. Replace the toner cartridge with a new one.
Step Cause Check
Result Remedy
1
HVPS PCB
failure
Is the problem solved
after replacing the
HVPS PCB ASSY?
Ye s
Replace the HVPS PCB
ASSY.
2
Main PCB failure Is the problem solved
after replacing the main
PCB ASSY?
Ye s
Replace the main PCB
ASSY.
User Check
• The paper tray ground terminal located in the machine
body may be dirty. Clean the contact with a dry cloth.
Step Cause Check
Result Remedy
1
Dirt on charge
electrode
Are the electrodes on
the drum unit and
machine body dirty?
Ye s
Clean both electrodes.
(Refer to Fig. 1-1, Fig. 1-2.)
2
Paper tray
ground terminal
located in
machine body
Is the paper tray ground
terminal bent, which is
located in the machine
body?
Ye s
Correct the bending of
paper tray ground terminal.
3
Laser unit failure Is the problem solved
after replacing the laser
unit?
Ye s
Replace the laser unit.