Toshiba FD-4809, Service Manual

Page: 18 / 47

19
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, 86.9mV sine
waveform is applied to TEL-
line of the base, can the 1 kHz
sine waveform from the Q2
collector be fed? Check the base TEL-line
circuit and REPLAY control
circuit.
NG
Check whether there is the
1 kHz sine wavefor m at
pin 12 of IC2. Check Q3 and its peripheral
circuit. NG
OK
OK
TX output signal from the
base is detected by the liner
detector, can the app. 30kHz
pulse waveform be fed?
Check base RF unit.
NG
OK
Check whether there is the
1 kHz sine waveform at pin 22
of IC602 on the handset unit. NG
OK
Check whether there is the
1 kHz sine waveform at pin
17 of IC602. Check C611, R631, R629,
R639, R641, C670, C671. NG
OK
Check whether there is the
1 k H z s i n e w a v e f o r m
between 1 and 2 of SP801. Check C612, C614, W801,
W802. NG
OK
Check SP801.
Check handset RF unit.