Brother MFC-7240 - Control Panel Troubleshooting; Nothing Is Displayed on the LCD; The Control Panel Does Not Work; Lamp Malfunction

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3.10 Control Panel Troubleshooting
3.10.1 Nothing is displayed on the LCD
3.10.2 The control panel does not work
3.10.3 Lamp malfunction
<User Check>
- Check that the power switch is turned ON.
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
failure
Replace the low voltage power supply PCB
ASSY.
6 Panel PCB failure Replace the panel PCB ASSY.
7 Main PCB failure Replace the main PCB ASSY.
<User Check>
- Turn the power OFF and ON.
Step Cause Remedy
1 Panel unit attachment failure Reattach the panel unit.
2
Connection failure of the panel PCB
harness
Reconnect the panel PCB harness.
3 Rubber key failure Replace the rubber key.
4 Panel PCB failure Replace the panel PCB ASSY.
5 Main PCB failure Replace the main PCB ASSY.
Step Cause Remedy
1
Connection failure of the panel PCB
harness
Reconnect the panel PCB harness.
2 Panel PCB failure Replace the panel PCB ASSY.
3 Main PCB failure Replace the main PCB ASSY.