Brother MFC-L6700DW - Nothing Is Displayed on the LED; Control Panel Is Inoperable

2-110
Confidential
4.6.2 Nothing is displayed on the LED
4.6.3 Control panel is inoperable
<User Check>
• Turn the power switch OFF and then ON again.
Step Cause Remedy
1
Connection failure of the key PCB
flat cable
Reconnect the key PCB flat cable.
2 Panel PCB failure Replace the panel PCB ASSY.
3 Key PCB failure Replace the panel unit.
4 Main PCB failure Replace the main PCB ASSY.
<User Check>
• Turn the power switch OFF and then ON again.
Step Cause Remedy
1
Connection failure of the panel flat
cable
Reconnect the panel flat cable.
2 Panel PCB failure Replace the panel PCB ASSY.
3 Touch panel failure Replace the touch panel ASSY.
4
Low-voltage power supply PCB
failure
Replace the low-voltage power supply PCB
ASSY.
5 Key PCB failure Replace the panel unit.
6 Main PCB failure Replace the main PCB ASSY.