Troubleshooting Procedures; 1 ] Control Panel Related; 2 ] Telephone Related - Brother MFC6800 Service Manual

6.2.4 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) Speaker silent during on-hook
dialing.
(4) Dial does not switch between tone
and pulse.
(5) Telephone does not ring.
Panel harness between the control panel PCB and relay
PCB
Relay (CCD/PANEL) harness between the relay PCB
and main PCB
Control panel PCB
Low-voltage power supply PCB
Main PCB
LCD
Panel harness between the control panel PCB and relay
PCB
Relay (CCD/PANEL) harness between the relay PCB
and main PCB
Control panel PCB
FPC key
Main PCB
FPC key
Control panel PCB
NCU PCB
Main PCB
Ordinary dialing function (other than the speed and
one-touch dialing)
If it works normally, check the main PCB; if not, refer
to item (1) above.
Ordinary dialing function (other than the on-hook
dialing with the hook key)
If it works normally, proceed to the following checks; if
not, refer to item (1) above.
Main PCB
NCU PCB
Speaker
NCU PCB
Main PCB
6 -1 9
Check:
Check: