YES
Can the video/voice
communication be made?
NO
YES
Are all parts on
Talk Signal Path (Transmitting)
of Extension Monitor Station
OK?
NO
Advance preparation:
Connect a non-defective Door
Station and Extension Monitor Station
to the Main Monitor Station.
Communicate between the Extension
Monitor Station and the Door Station.
Replace the fault parts.
START
END
YES
Are all parts on
Talk Signal Path (Receiving)
of Extension Monitor Station
OK?
NO
Replace the fault parts.
YES
Are all parts on
Image Signal Path
of Extension Monitor Station
OK?
NO
Replace the fault parts.
Replace the Main board of
EXtention Monitor Station. (*1)