Brother HL-3040CN Service Manual page 142

■ Fogging
<User Check>
- Replace the toner cartridge with a new one.
- Replace the drum unit with a new one.
- Do not use acid paper.
Step Cause
1 Toner/new
sensor PCB failure
2 HVPS control PCB
failure
3 High-voltage power
supply PCB failure
4 Engine PCB failure
Note:
This problem often occurs when the drum unit or toner cartridge is nearly at the end of life.
Check
Is the toner sensor
performed normally by
following the procedure
described in "Function
code 32" to check?
Is the problem solved
after replacing the HVPS
control PCB ASSY?
Is the problem solved
after replacing the
high-voltage power
supply PCB ASSY?
Is the problem solved
after replacing the
engine PCB ASSY?
3-78
Remedy
Result
No Replace the toner/new
sensor PCB ASSY.
Yes Replace the HVPS
control PCB ASSY.
Yes Replace the
high-voltage power
supply PCB ASSY.
Yes Replace the engine
PCB ASSY.
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