Toshiba FT-8509 Service Manual page 18

3. The base and handset cannot be connected.
Check whether the
base is able to set in the
test mode 1.
OK
Check the TX POWER
and the TX FREQUENCY
on the base unit.
OK
Set the base in the test
mode 3, check whether
deviation of the TX data
is app. 8 kHz Dev.
OK
Set the base in the test
mode 8, 902.952467
MHz (250 Hz ±8 kHz
Dev.) 1mV output signal
from RF jack is applied.
Does the bell ring?
OK
Check whether the
handset is able to set in
the test mode 1.
OK
Check the TX POWER
and the TX FREQUENCY
on the handset unit.
OK
A
NG
Check IC10 and its
peripheral circuit.
NG
Check base RF unit.
NG
Check whether there is
a 250Hz data waveform
at C50.
OK
Check base RF unit.
NG
Check whether there is
a 250 Hz data waveform
at pin 9 of IC2.
OK
Check whether there is
a 250 Hz data waveform
at the Q2 collector.
OK
Check whether there is
a 250 Hz data waveform
at pin 17 of IC10.
OK
Check IC10 and its
peripheral circuit.
NG
Check IC404 and its
peripheral circuit.
NG
Check handset RF unit.
NG
Check RT3, R56, C60,
C59, R55 and C50.
NG
Check base RF unit.
NG
Check RT2, Q2 and
their peripheral circuit.
NG
Check IC1 and its
peripheral circuit.
18