Brother HL-4040CN Service Manual page 40

Error code 76
Print Unable 76
Turn the power off and then back on again.
Fuser unit failure (The center thermistor detects rapid temperature rising.)
Step
1 Fuser unit failure
Error code 78
Print Unable 78
Turn the power off and then back on again.
Fuser unit failure (The center thermistor detects rapid temperature falling.)
Step
1 Harness connection failure
between fuser unit connector
and engine PCB
2 Fuser unit failure
Error code 7D
Drum Error
Slide the Green tab on Drum Unit in each color. Refer to the User's
Guide for the procedures.
Dirt on drum unit
User Check
- Clean the corona wire in the drum unit.
- Replace the drum unit with a new one.
Step
1 Dirt or dust on drum unit
electrodes
2 Charge HVPS PCB failure
3 Engine PCB failure
Cause
Replace the fuser unit.
Cause
Check the harness connection between the fuser
unit connector and engine PCB, and reconnect it.
Replace the fuser unit.
Cause
Clean the electrodes on the drum unit.
(Refer to
Replace the charge HVPS PCB ASSY.
Replace the engine PCB ASSY.
1-23
Remedy
Remedy
Remedy
Fig. 1-2.)
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