TOSHIBA FT7800A
Manual de Servicio

Press the "3" key, check whether deviation of the TX data is app. ±35 kHz Dev. OK

NG

Check whether there is a 250Hz data waveform at C717. OK Check handset RF unit (B850).

NG

Check RT603, R626, R672, R673, R679, R680 and C642.

Press the "6" key, and apply NG 926.207269 MHz (250 Hz ±35 kHz Dev.) 1mV output signal from RF jack. Check whether the bell ring. OK Place the handset on the base to charge about 5 seconds, then connect again.

Check whether the 250 Hz data wareform from pin 28 of IC601. OK Check whether there is a 250 Hz data waveform at pin 24 of IC601. OK

NG

Check handset RF unit and the peripheral circuit of IC601.

NG

Check R614, R703, C631, C632 and their peripheral circuits.

Check whether there is a 250 Hz data waveform at pin 40 of IC602. OK Check IC602 and its peripheral circuit.

NG

Check R616, R663 and their peripheral circuits.

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