Set the handset in the test mode 3, check whether deviation of the TX data is app. 7 kHz Dev. OK
NG
Check whether there is a 250Hz data waveform at Pin 9 of J601. OK
NG
Check VR601, R619, R632, R634, R635, R636 and C611.
Check handset RF unit.
Set the handset in the test mode 6, 927.000602 MHz (250 Hz ±7 kHz Dev.) 1mV output signal from RF jack is applied. Check whether the bell ring. OK Place the handset on the base to charge about 5 seconds, then connect again.
NG
Check whether the 250 Hz data wareform from Pin 1 of J601 is fed. OK Check whether there is a 250 Hz data waveform at the Q601 collector. OK
NG Check handset RF unit.
NG
Check VR602, Q601 and their peripheral circuits.
Check whether there is a 250 Hz data waveform at Pin 55 of IC603. OK Check IC603 and its peripheral circuit.
