Brother DCP 8085DN

3-49
Confidential
■ Completely blank
■ Image distortion
<User Check>
- Replace the drum unit with a new one.
- Replace the toner cartridge with a new one.
Step Cause Check
Result Remedy
1
Developing bias
voltage
conduction
failure
Are the electrodes on
the drum unit and
machine body dirty?
Yes
Clean both electrodes.
(Refer to Fig. 3-2, Fig. 3-3.)
2
Scanner harness
of the laser unit
connection
failure
Is the scanner harness
of the laser unit
connected securely?
No
Reconnect the scanner
harness of the laser unit.
3
Laser unit failure Is the problem solved
after replacing the laser
unit?
Yes
Replace the laser unit.
4
HVPS PCB
failure
Is the problem solved
after replacing the
HVPS PCB ASSY?
Yes
Replace the HVPS PCB
ASSY.
5
Main PCB failure Is the problem solved
after replacing the main
PCB ASSY?
Yes
Replace the main PCB
ASSY.
Step Cause Check
Result Remedy
1
Laser unit not
assembled
correctly
Is the laser unit
assembled into the
machine securely?
(Check if there is no
gap.)
No
Assemble the laser unit
correctly and secure the
screw.
2
Incorrect
radiation angle of
scanner diode of
laser unit.
Scanner motor
rotation failure
Is the problem solved
after replacing the laser
unit?
Yes
Replace the laser unit.
3
Main PCB failure Is the problem solved
after replacing the main
PCB ASSY?
Yes
Replace the main PCB
ASSY.