VI - 13
2.4 Troubleshooting Procedures
[ 1 ] Control panel related
Trouble Check:
(1) LCD shows nothing. •Panel-main harness between the main PCB and the control PCB
•Interfaces between the main PCB, NCU PCB and power supply
PCB
•LCD
•Control panel PCB
•Power supply PCB
•Main PCB
(2) Control panel inoperative. •Panel-main harness between the main PCB and the control PCB
•Interfaces between the main PCB, NCU PCB and power supply
PCB
•Control panel PCB
•FPC key
•Main PCB
[ 2 ] Telephone related
Trouble Check:
(1) No phone call can be made. •FPC key
•Control panel PCB by using the maintenance-mode function
code 13. If any defective keys are found, replace them. (Refer
to Chapter V, Section 3.7, "Operational Check of Control Panel
PCB.")
•NCU PCB
•Main PCB
(2) Speed dialing or one-touch
dialing will not work. •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.
(3) Speaker silent during on-hook
dialing. •Ordinary dialing function (Pick up the handset and press the
numerical keys.)
If it works normally, proceed to the following checks; if not, refer
to item (1) above.
(4) Dial does not switch between
tone and pulse. •Main PCB
(5) Telephone does not ring. •Speaker
•NCU PCB
•Main PCB