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Troubleshooting Flow Chart
Descriptions of normal situation:
[1] Output voltage by Q601 Pin 3 is about 3.3 V.
[2] Output voltage by U306 Pin 5 or input voltage by Q601 Pin 4 is about 3.3V.
[3] Check the collector voltage and base voltage of Q602 when the radio is not receiving. Normally, the
base voltage is about 0.7 V, the collector voltage is about 2.7 V and the emitter voltage is 0 V.
[4] Check the collector voltage and base voltage of Q604 when the radio is not receiving. Normally, the
base voltage is about 0.7 V, the collector voltage is about 2.9 V and the emitter voltage is 0 V.
[5] Cut off the front-end circuit, and input an IF signal (with modulation signal) at C651 to test IF
sensitivity. Normally, the IF sensitivity is -109 dBm.
[6] Input a -40 dBm RF signal in the antenna port and test at R631. Normally, gain is greater than 10 dB
and output signal is greater than -30 dBm.
[7] Test at C659 when the post-stage circuit has not been cut off. Normally, the frequency equals the
difference between the current channel frequency and IF, and the amplitude is about 1 dBm.
[8] Test at D1008 when the post-stage circuit has not been cut off. Normally, the frequency is difference
between the current channel frequency and IF, and the amplitude is about 5 dBm.
[9] Frequency output by mixer is the value of IF.
[10] The input signal at antenna port, with standard tuning information (AF=1 kHz; FM=3 kHz), is -47
dBm.
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