Toshiba FT-7807R Service Manual page 15

Then, can the sine wave
be seen at the Q2 Collector.
OK
Check the surrounding
circuit of T1.
4. Cannot make a phone call (pulse).
Can the base and handset
be connected?
OK
While in TALK MODE,
press dial key of the
handset. Can pulse
feedback be heard from
the handset speaker?
OK
Check the base TEL-line
network primary circuit.
5. Cannot make a phone call (tone).
Can the base and handset
be connected?
OK
While in TALK MODE,
press dial key of the
handset. From the
speaker, does the TONE
ring up?
OK
Check the base TEL-line
circuit and RELAY control
circuit.
NG
NG
NG
NG
NG
Check the base modulation
sensitivity.
At Pin 20 of IC5 of the
base, can the TONE
wave output be seen?
Check R45, R46, R49 and
C56.
— 16 —
NG
OK
NG
OK
Check Q2 and surrounding
circuit of Q2.
See 3. The base and
handset cannot connect.
Check the base RELAY
control (around Pin23
of IC2.
See 3. The base and
handset cannot connect.
Check the base TX AF
circuit (around Pins 17,
19~21 of IC1).
Check IC5 by using
voltage chart.