Troubleshooting Procedures; 1 ] Control Panel Related; 2 ] Telephone Related - Brother FAX255 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.
• Main-panel harness between the main PCB and the
control panel PCB
• Interfaces between the main PCB, NCU PCB and power
supply PCB
• Control panel PCB
• Power supply PCB
• Main PCB
• Main-panel harness between the main PCB and the
control panel PCB
• Interfaces between the main PCB, NCU PCB and power
supply PCB
• Control panel PCB
• FPC key
• Main PCB
• FPC key
• Control panel PCB by using the maintenance-mode
function No. 13. If any defective keys are found, replace
them. (Refer to Chapter V, Section 3.7.)
• 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
VI – 12
Check:
Check: