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 - Brother FAX-2840 Service Manual

3.12 Other Troubleshooting

3.12.1 The machine is not turned ON or the LCD indication does not appear

Step
1 AC cord failure
Connection failure of the panel PCB
2
harness
Connection failure of the LCD
3
harness
4 LCD failure
Low voltage power supply PCB
5
ASSY failure
6 Panel PCB failure
High voltage power supply PCB
7
failure
8 Main PCB failure

3.12.2 Main fan does not rotate

Step
Connection failure of the main fan
1
harness
Connection failure of the high
2
voltage power supply PCB harness
3 Main fan failure
High voltage power supply PCB
4
failure
5 Main PCB failure

3.12.3 The room temperature is high or low

<User Check>
- Adjust the room temperature to 10°C to 30°C.
- Check that the exhaust opening is not blocked.
Step
Internal temperature thermistor
1
failure
2 Main PCB failure
Cause
Replace the AC cord.
Reconnect the panel PCB harness.
Reconnect the LCD harness.
Replace the LCD.
Replace the low voltage power supply PCB
ASSY.
Replace the panel PCB ASSY.
Replace the high voltage power supply PCB
ASSY.
Replace the main PCB ASSY.
Cause
Reconnect the main fan harness.
Reconnect the high voltage power supply
PCB harness.
Replace the main fan.
Replace the high voltage power supply PCB
ASSY.
Replace the main PCB ASSY.
Cause
Replace the internal temperature
thermistor.
Replace the main PCB ASSY.
2-84
Remedy
Remedy
Remedy
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