Troubleshooting Procedures; 1 ] Control Panel Related; 2 ] Telephone Related - Brother MFC 9760 - B/W Laser - All-in-One Service Manual

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
l
relay PCB
Main-relay (panel) harness between the relay PCB and
l
main PCB
Control panel PCB
l
Low-voltage power supply PCB
l
Main PCB
l
LCD
l
Panel harness between the control panel PCB and
l
relay PCB
Main-relay (panel) harness between the relay PCB and
l
main PCB
Control panel PCB
l
FPC key
l
Main PCB
l
FPC key
l
Control panel PCB
l
NCU PCB
l
Main PCB
l
Ordinary dialing function (other than the speed and
l
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
l
dialing with the hook key)
If it works normally, proceed to the following checks; if
not, refer to item (1) above.
Main PCB
l
Speaker
l
NCU PCB
l
Main PCB
l
VI - 19
Check:
Check: