Low Voltage Power Supply Pcb Assy Failure; Ncu Assy Failure - Brother DCP-7055 Service Manual

3.13.4 Low voltage power supply PCB ASSY failure

User Check
• Turn the power off and on.
Step
Harness connection failure of low
1 voltage power supply PCB ASSY
Low voltage power supply PCB
failure
2
3 Main PCB failure
CAUTION :
• The irregular power supply detection error EF occurs when there is a large fluctuation
in the power supply voltage supplied to the machine.
In this case, if the same power supply is used, the same error might occur again even
if the low voltage power supply PCB ASSY is replaced.

3.13.5 NCU ASSY failure

User Check
• Verify that the telephone cord is securely inserted into the right socket..
Step
Harness connection failure of NCU
1
ASSY
2 NCU ASSY failure
Cause
Cause
2-103
Remedy
Check the harness connection of the low
voltage power supply PCB ASSY, and
reconnect it.
Replace the low voltage power supply
PCB ASSY. However, in the failure case
of that the irregular power supply is
detected, reset the irregular power supply
detection counter following the procedure
described in "3.1 Reset of Irregular Power
Supply Detection Counter" in Chapter
Replace the main PCB ASSY.
Remedy
Check the harness connection of the
NCU ASSY, and reconnect it.
Replace the NCU ASSY.
4.
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