Troubleshooting Procedures; 1 ] Control Panel Related; 2 ] Telephone Related - Brother MFC4820C Service Manual

8.2.4 Troubleshooting Procedures

[ 1 ] Control panel related
Trouble
(1) LCD shows nothing.
(2) Control panel inoperative.
[ 2 ] Telephone related
Trouble
(1) No phone call can be made.
(2) Speed dialing or one-touch
dialing will not work.
(3) Dial does not switch between
tone and pulse.
(4) Telephone does not ring.
• Panel-main harness
• Control panel PCB
• Power supply PCB
• Main PCB
• Panel-main harness
• Control panel PCB
• Main PCB
• Control panel PCB
• NCU PCB
• Main PCB
• Ordinary dialing function (other than the speed and one-touch
dialing)
If it works normally, check the driver PCB; if not, refer to
item (1) above.
• Main PCB
• Speaker
• NCU PCB
• Main PCB
8 -1 5
Check:
Check: