Brother MFC-7240 - Other Troubleshooting; The Machine Is Not Turned on or the LCD Indication Does Not Appear; Main Fan Does Not Rotate; The Room Temperature Is High or Low

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3.12 Other Troubleshooting
3.12.1 The machine is not turned ON or the LCD indication does not appear
3.12.2 Main fan does not rotate
3.12.3 The room temperature is high or low
Step Cause Remedy
1 AC cord failure Replace the AC cord.
2
Connection failure of the panel PCB
harness
Reconnect the panel PCB harness.
3
Connection failure of the LCD
harness
Reconnect the LCD harness.
4 LCD failure Replace the LCD.
5
Low voltage power supply PCB
ASSY failure
Replace the low voltage power supply PCB
ASSY.
6 Panel PCB failure Replace the panel PCB ASSY.
7
High voltage power supply PCB
failure
Replace the high voltage power supply PCB
ASSY.
8 Main PCB failure Replace the main PCB ASSY.
Step Cause Remedy
1
Connection failure of the main fan
harness
Reconnect the main fan harness.
2
Connection failure of the high
voltage power supply PCB harness
Reconnect the high voltage power supply
PCB harness.
3 Main fan failure Replace the main fan.
4
High voltage power supply PCB
failure
Replace the high voltage power supply PCB
ASSY.
5 Main PCB failure Replace the main PCB ASSY.
<User Check>
- Adjust the room temperature to 10°C to 30°C.
- Check that the exhaust opening is not blocked.
Step Cause Remedy
1
Internal temperature thermistor
failure
Replace the internal temperature
thermistor.
2 Main PCB failure Replace the main PCB ASSY.