Troubleshooting For Control Panel Problems; Nothing Is Displayed On The Lcd - Brother DCP-L8400CDN Service Manual

4.6

Troubleshooting for Control Panel Problems

4.6.1

Nothing is displayed on the LCD

< User Check >
- Turn the power OFF/ON.
Step
1
2
3
4
5
6
7
8
9
10
11
Cause
The version of the panel
firmware and the main
firmware do not match.
Connection failure of the key
PCB flat cable
Connection failure of the
panel PCB harness
Connection failure of the LCD
flat cable
Connection failure of the
low-voltage power supply
PCB harness
AC cord failure
Panel PCB failure
LCD failure
Key PCB failure
Low-voltage power supply
PCB failure
Main PCB failure
Install the latest panel firmware and main
firmware.
Reconnect the key PCB flat cable.
Reconnect the panel PCB harness.
Reconnect the LCD flat cable.
Reconnect the low-voltage power supply
PCB harness.
Replace the AC cord.
Replace the panel PCB unit.
Replace the LCD.
Replace the panel cover ASSY.
Replace the low-voltage power supply PCB
unit.
Replace the main PCB ASSY.
2-116
Remedy
Confidential