Troubleshooting For Fuser Unit Problems; Fuser Unit Failure - Brother HL-5440D Service Manual

4.8

Troubleshooting for Fuser Unit Problems

4.8.1 Fuser unit failure

Step
Harness connection failure
1 between fuser unit and eject sensor
PCB
Harness connection failure
2 between fuser unit and low-voltage
power supply PCB
Connection failure of the eject
3
sensor harness
Eject sensor PCB failure
4
Low-voltage power supply PCB
5
failure
6 Fuser unit failure
7 Main PCB failure
CAUTION:
• Turn the power switch OFF and then ON again. Leave the machine for ten minutes.
This problem may then be cleared.
• The machine may recover from the error, when fuser unit inspection print is conducted
after the following operation: Open the cover, and turn the power switch ON while
pressing the [Go] button, then press the [Go] button one time, and then press the [Go]
button three times. However, conducting this operation while the heater has not yet
cooled may cause the fuser unit to melt. Be careful.
Cause
Check the harness connection between the
fuser unit and the eject sensor PCB, and
reconnect it if necessary.
Check the harness connection between the
fuser unit and the low-voltage power supply
PCB, and reconnect it if necessary.
Check the connection of the eject sensor
harness, and reconnect it if necessary.
Refer to
(function code: 32)" in Chapter 5
the sensor operation. If the sensor operation
is faulty, replace the eject sensor PCB
ASSY.
Replace the low-voltage power supply PCB
ASSY.
Replace the fuser unit.
Replace the main PCB ASSY.
2-77
Remedy
"1.3.8 Check sensor operation
to check
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