Toshiba FT-8901A, Руководство по обслуживанию

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7. The voice of the caller cannot be heard (incoming call).
Can the base and handset be
connected? See 3. The base and handset
cannot be connected.
OK
NG
The 1 kHz, -10.5dBm sine
waveform is applied to TEL-
line of the base, can the 1 kHz
sine waveform from the Q3
collector be fed? Check the base TEL-line
circuit and RELAY control
circuit.
NG
Check whether there is the
1 kHz sine wavefor m at
Pin 24 of IC2. Check Q15 and its peripheral
circuit. NG
OK
OK
Check whether there is the
1 kHz sine wavefor m at
Pin 20 of IC2. Check IC2 and its peripheral
circuit.
NG
OK
TX output signal from the
base is detected by the liner
detector, can the 1 kHz sine
waveform be fed?
Check base RF section.
NG
OK
Check whether there is the
1 kHz sine waveform at Pin 9
of IC603 on the handset unit. Check IC603 and its
peripheral circuit. NG
OK
Check whether there is the
1 kHz sine waveform at Pin 3
of IC602 and Pin 5 or Pin 6
of IC602. Check IC602 and its
peripheral circuit. NG
OK
Check whether there is the
1 kHz sine waveform at the
Q615 collector. Check Q615 and its
peripheral circuit. NG
OK
Check whether there is the
1 kHz sine waveform at Pin
1, 2 of SP801. NG
OK
Check SP801 and W801,
W802.
Check handset RF section.
NG
OK
Check whether there is the
1 kHz sine wavefor m at
RT2. Check RT2 and its
peripheral circuit. NG
OK
Check Q604 Q605 and
their peripheral circuits.