Troubleshooting For Pcb Problems - Brother HL-5440D Service Manual

4.10 Troubleshooting for PCB Problems

4.10.1 Main PCB failure
<User Check>
- Turn the power switch OFF and then ON again.
- Install the latest firmware.
Step
1 Main PCB failure
4.10.2 High-voltage power supply PCB failure
Step
Connection failure of the high-
voltage power supply PCB harness
1
Contact failure of electrode
2 terminals of the high-voltage power
supply PCB
High-voltage power supply PCB
3
failure
Low-voltage power supply PCB
4
failure
5 Main PCB failure
4.10.3 Low-voltage power supply PCB failure
Step
Connection failure of the low-
1 voltage power supply PCB harness
Low-voltage power supply PCB
2 failure
3 Main PCB failure
CAUTION:
• The irregular power supply detection error (error code EF00) occurs when there is a
large distortion in the power supply voltage supplied to the machine. In this case, if the
same power supply is used, the same error may occur even when the low-voltage
power supply PCB ASSY is replaced. Ask the user to review the installation
environment.
The following LED status also indicates that this error is current: When the Back Cover,
Toner, Drum, Paper, Error and Ready LEDs flash, press the [Go] button. The Toner,
Drum, Paper and Error LEDs remain lit. Press the [Go] button again, and the Toner and
Ready LEDs remain lit.
Cause
Replace the main PCB ASSY.
Cause
Check the harness connection between the
high-voltage power supply PCB and the
main PCB ASSY, and reconnect it if
necessary.
Clean the electrode terminals of the high-
voltage power supply PCB.
Replace the high-voltage power supply PCB
ASSY.
Replace the low-voltage power supply PCB
ASSY.
Replace the main PCB ASSY.
Cause
Check the connection of the low-voltage
power supply PCB harness, and reconnect
it if necessary.
Replace the low-voltage power supply PCB
ASSY, and reset the irregular power supply
detection counter.
Replace the main PCB ASSY.
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Remedy
Remedy
Remedy
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