Brother DCP-7090 Service Manual page 90

 Error code 0900
Detected irregular power supply for more than 100 times.
Step
Low-voltage power supply PCB
failure
1
2 Main PCB failure
Note:
The irregular power supply detection error (Error code 0900) of the low-voltage power
supply PCB 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 might occur
again even if the low-voltage power supply PCB ASSY is replaced. For this reason, be sure
to ask the user to rearrange the installation environment.
 Error code 0A02
Detected a fan failure.
Step
Connection failure of the fan
1
harness
Connection failure of the high-
2 voltage power supply PCB
harness
3 Fan failure
High-voltage power supply PCB
4
failure
5 Main PCB failure
Cause
Cause
2-50
Remedy
Replace the low-voltage power supply
PCB ASSY. Refer to "1.3.30 Reset
irregular power supply detection counter
of low-voltage power supply PCB
(Function code 88)" in Chapter 5
the irregular power supply detection
counter after the replacement.
Replace the main PCB ASSY.
Remedy
Reconnect the fan harness.
Reconnect the high-voltage power supply
PCB harness.
Replace the fan.
Replace the high-voltage power supply
PCB ASSY.
Replace the main PCB ASSY.
to reset
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