Brother FAX-921 - Manual (Page 164)

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