Brother DCP-8070D Service Manual page 167

■ Speaker is silent during on-hook dialing.
Step Possible cause
Connection
between main
1
PCB and
speaker
Connection
between main
2
PCB and NCU
PCB
Connection
between main
3
PCB and control
panel PCB
Speaker
4
NCU PCB
5
Main PCB
6
■ Dialing function does not switch between "tone" and "pulse".
Step Possible cause
Connection
between main
1
PCB and NCU
PCB
NCU PCB
2
Main PCB
3
Check
Are the main PCB and
speaker connected
properly?
Are the main PCB and
NCU PCB connected
properly?
Are the main PCB and
control panel PCB
connected properly?
Is the problem solved
after replacing the
speaker?
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
properly?
Is the problem solved
after replacing the NCU
PCB ASSY?
Is the problem solved
after replacing the main
PCB ASSY?
3-76
Result Remedy
Reconnect the connector
properly.
No
Reconnect the connector
properly.
No
Reconnect the connector
properly.
No
Replace the Speaker.
Yes
Replace the NCU PCB
Yes ASSY.
Replace the main PCB
Yes ASSY.
Result Remedy
Reconnect the connector
properly.
No
Replace the NCU PCB
Yes ASSY.
Replace the main PCB
Yes ASSY.
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