4. Cannot make a phone call (pulse).
Can the base and handsetNGSee 3. The base and handset
be connected?cannot be connected.
OK
While in TALK MODE, pressNG
dial key of the handset.Check IC4.
Check whether square
waveform from pin 80 of
IC4 is fed.
OK
Check Q21, RL1 and their
peripheral circuits.
5. Cannot make a phone call (tone).
Can the base and handset beNGSee 3. The base and handset
connected?be cannot be connected.
OK
While in TALK MODE, pressNG
dial key of the handset.Check IC4.
Can tone waveform from Pin
36 of IC4 is fed?
OK
Can tone signal be heardNGCheck Q13, IC1, Q3 and
from the handset speaker?their peripheral circuits.
OK
Check the base TEL-line
circuit and RELAY control
circuit.
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