Troubleshooting Of The Control Panel; Nothing Is Displayed On The Lcd; The Control Panel Does Not Work - Brother DCP-9055CDN Service Manual

3.11 Troubleshooting of the Control Panel

3.11.1 Nothing is displayed on the LCD

<User Check>
- Verify if the power switch is turned off.
Step
1
2
3
4
5
6
7
8
9

3.11.2 The control panel does not work

<User Check>
- Check whether the function lock is not set.
Step
1
2
3
4
5
Cause
AC cord failure
Connection between main
PCB and panel PCB
Connection between main
PCB and low-voltage power
supply PCB
Power switch holder failure
LCD or LCD unit failure
Panel PCB failure
High-voltage power supply
PCB failure
Low-voltage power supply
PCB failure
Main PCB failure
Cause
Key sticking
Connection between main
PCB and panel PCB
Fine adjustment of touch
panel misalignment (for
models with a touch panel)
Panel PCB failure
Main PCB failure
Replace the AC cord.
Connect the connector between the main
PCB ASSY and panel PCB ASSY correctly.
Connect the connector between the main
PCB ASSY and low-voltage power supply
PCB ASSY correctly.
Replace the power switch holder.
Replace the LCD or LCD unit.
Replace the panel PCB ASSY.
Replace the high-voltage power supply PCB
ASSY.
Replace the low-voltage power supply PCB
ASSY.
Replace the main PCB ASSY.
Re-assemble the panel unit.
Connect the connector between the main
PCB ASSY and panel PCB ASSY correctly.
Perform the fine adjustment of touch panel.
(Function code
Replace the panel PCB ASSY.
Replace the main PCB ASSY.
2-133
Remedy
Remedy
61)
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