Troubleshooting For Control Panel Problems; Nothing Is Displayed On The Lcd; Nothing Is Displayed On The Led - Brother HLL3290CDW Service Manual

4.6

Troubleshooting for Control Panel Problems

4.6.1

Nothing is displayed on the LCD

<User Check>
• Turn the power switch OFF and then back ON again.
• Unplug the AC cord and then plug it again.
Step
1
2
3
4
5
6
7
8
9
10
4.6.2

Nothing is displayed on the LED

<User Check>
• Turn the power switch OFF and then back ON again.
Step
1
2
3
4
Cause
Connection failure of the
panel flat cable
Connection failure of the low-
voltage power supply harness
Connection failure of the high-
voltage power supply flat cable
(Touch panel models only)
Connection failure of the LCD
flat cable
AC cord failure
Panel flat cable failure
LCD failure
Panel PCB failure
Low-voltage power supply
PCB failure
Main PCB failure
Cause
Connection failure of the key
flat cable
Panel flat cable failure
Key PCB failure
Main PCB failure
Reconnect the panel flat cable.
Reconnect the low-voltage power supply
harness.
Reconnect the high-voltage power supply flat
cable.
Reconnect the LCD flat cable.
Replace the AC cord.
Replace the panel flat cable.
Replace the LCD.
Replace the panel PCB.
Replace the low-voltage power supply PCB.
Replace the main PCB.
Reconnect the key flat cable.
Replace the panel flat cable.
Replace the key PCB.
Replace the main PCB.
2-138
Remedy
Remedy
Confidential