1. The bell does not ring.
When the INTCOM key of
the base is pressed, does
the ringer on the handset
ring?
OK
When the TEL SG is joined
with the base to make bell
signal, is there pulse wave
at Pin 4 of IC3?
OK
Is there pulse wave at
Pin 33?
OK
Check IC18 and its
peripheral circuit.
TROUBLESHOOTING HINTS
See 2. The bell does not
NG
ring & page does not ring.
Check IC3 and TEL network
NG
circuit.
NG
Check R42, R80, R107 and
C51.
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