■ Speaker is silent during on-hook dialing.
Step
Cause
Connection
between main
1
PCB and
speaker
Speaker
2
Connection
between main
3
PCB and NCU
PCB
Connection
between main
4
PCB and control
panel PCB
NCU PCB
5
Main PCB
6
■ Dialing function does not switch between "tone" and "pulse".
Step
Cause
Connection
between main
1
PCB and NCU
PCB
NCU PCB
2
Main PCB
3
Check
Are the main PCB and
speaker connected
correctly?
Is the problem solved
after replacing the
speaker?
Are the main PCB and
NCU PCB connected
correctly?
Are the main PCB and
control panel PCB
connected correctly?
Is the problem solved
after replacing the NCU
PCB ASSY?
Is the problem solved
after replacing the main
PCB ASSY?
Check
Are the main PCB and
NCU PCB connected
correctly?
Is the problem solved
after replacing the NCU
PCB ASSY?
Is the problem solved
after replacing the main
PCB ASSY?
1-56
Result
Remedy
Reconnect the connector.
No
Replace the Speaker.
Yes
Reconnect the connector.
No
Reconnect the connector.
No
Replace the NCU PCB
Yes
ASSY.
Replace the main PCB
Yes
ASSY.
Result
Remedy
Reconnect the connector.
No
Replace the NCU PCB
Yes
ASSY.
Replace the main PCB
Yes
ASSY.
Confidential