TOSHIBA FT8908
Service Manual

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. 7 kHz Dev. OK Check base RF unit. NG Check whether there is a 250 Hz data waveform at Pin 9 of J2. OK NG Check R37, R38, R39 R68, R69 and C27. NG Check base RF unit. NG Check IC22 and its peripheral circuit.

Set the base in the test mode 8, 902.984676 MHz (250 Hz ±7 kHz Dev.) 1 mV output signal from RF jack is applied. Does the bell ring? OK

NG

Check whether there is a 250 Hz data waveform at Pin 1 of J2. OK Check whether there is a 250 Hz data waveform at the Q1 collector. OK Check whether there is a 250 Hz data waveform at Pin 38 of IC22. OK Check IC22 and its peripheral circuit.

NG Check base RF unit.

NG

Check RT1, Q1 and their peripheral circuits.

NG

Check Q9, Q10 and their peripheral circuits.

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

NG

Check IC603 and its peripheral circuit.

NG Check handset RF unit.

� 28 �