Troubleshooting For Control Panel Problems; Nothing Is Displayed On The Lcd; Nothing Is Displayed On The Led; Control Panel Is Inoperable - Brother HL-L2300D 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 ON again.
Step
Rubber key attachment failure
1
Connection failure of the panel PCB
2
flat cable
Connection failure of the LVPS
3
harness
Power cord failure
4
Rubber key failure
5
Panel PCB failure
6
LCD failure
7
Low-voltage power supply PCB
8
failure
Main PCB failure
9

4.6.2 Nothing is displayed on the LED

<User Check>
- Turn the power switch OFF and then ON again.
Step
Connection failure of the panel PCB
1
flat cable
Connection failure of the LVPS
2
harness
Power cord failure
3
Panel PCB failure
4
Low-voltage power supply PCB
5
failure
Main PCB failure
6

4.6.3 Control panel is inoperable

<User Check>
- Turn the power switch OFF and then ON again.
Step
Rubber key attachment failure
1
(LCD models)
Connection failure of the panel PCB
2
flat cable
Connection failure of the LVPS
3
harness
Rubber key failure (LCD models)
4
Panel PCB failure
5
Low-voltage power supply PCB
6
failure
Main PCB failure
7
Cause
Reattach the rubber key.
Reconnect the panel PCB flat cable.
Reconnect the LVPS harness.
Replace the power cord.
Replace the rubber key.
Replace the panel PCB ASSY.
Replace the LCD.
Replace the low-voltage power supply PCB
ASSY.
Replace the main PCB ASSY.
Cause
Reconnect the panel PCB flat cable.
Reconnect the LVPS harness.
Replace the power cord.
Replace the panel PCB ASSY.
Replace the low-voltage power supply PCB
ASSY.
Replace the main PCB ASSY.
Cause
Reattach the rubber key.
Reconnect the panel PCB flat cable.
Reconnect the LVPS harness.
Replace the rubber key.
Replace the panel PCB ASSY.
Replace the low-voltage power supply PCB
ASSY.
Replace the main PCB ASSY.
2-70
Remedy
Remedy
Remedy
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