Toshiba FT-8901, Service Manual

Page: 15 / 49

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3. The base and handset cannot be connected.
Check whether the base
is able to set in the test
mode 8.
OK
NG
A
Check IC4 and its
peripheral circuit.
Check base RF unit.
NG
Check the TX POWER
and the TX FREQUENCY
on the base unit.
OK
OK
NG
Check base RF unit.
NG Check whether there is a
250 Hz data waveform at
“MOD” of RF unit. Check RT3, R76, R91,
R49, C129, C122,
C33 and C52. NG
OK
Check base RF unit.
OK
NG Check whether there is a
250 Hz data waveform at
RT2 AF test point. Check IC3, Q1 and their
peripheral circuit. NG
OK
Check whether there is a
250 Hz data waveform at
the Q2 collector. Check RT2, Q2 and their
peripheral circuit. NG
OK
Check whether there is a
250 Hz data waveform at
pin 64 of IC4. NG
OK
Check IC4 and its
peripheral circuit.
Check whether the
handset is able to set in
the test mode 1.
OK
NG Check IC604 and its
peripheral circuit.
Check the TX POWER
and the TX FREQUENCY
on the handset unit.
OK
NG
Check handset RF unit.
OK
Check R27, R171, R172,
IC1 and their peripheral
circuit.
Set the base in the test
mode 10, check
whether deviation of the
TX data is app. 9.0 kHz
Dev.
Set the base in the test
mode 13,
902.952467MHz
(250 Hz ±8 kHz Dev.)
1mV output signal from
RF test point is
a p p l i e d . D o e s t h e
CHARGE LED light?