Brother HL-5340D Service Manual page 104

Downward fogging of solid color
<User Check>
- Toner may be empty. Replace the toner cartridge with a new one.
Step Cause
Toner sensor
failur
1
HVPS PCB
2 failure
Main PCB failure Is the problem solved
3
Horizontal lines
Step Cause
Dirt on charged
1 electrode
Paper tray
ground terminal
2
provided in
machine body
Laser unit failure
3
Check
Is the toner sensor
performed normally by
following the procedure
in "Factory Inspection
Mode" in 1.3 Service
Mode in Chapter 7.
Is the problem solved
after replacing the
HVPS PCB ASSY?
after replacing the main
PCB ASSY?
<User Check>
- The paper tray ground terminal provided in the machine
body may be dirty. Clean the contact with a dry cloth.
Check
Are the electrodes on
the drum unit and
machine body dirty?
Is the paper tray ground
terminal bent, which is
provided in the machine
body?
Is the problem solved
after replacing the laser
unit?
3-46
Result Remedy
Replace the toner sensor
PCB unit ASSY and the
toner LED PCB ASSY.
No
Replace the HVPS PCB
Yes ASSY.
Replace the main PCB
Yes ASSY.
Result Remedy
Clean both electrodes.
Yes (Refer to Fig. 3-2, Fig.
Correct bending of paper
tray ground terminal.
Yes
Replace the laser unit.
Yes
3-3.)
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