QCX+ Audio Problem


N1SP
 

Please forgive an often asked question, but in doing a search I only found folks with low voltages on IC10, which is different than my results...

Symptom: No audio tone when doing the BPF alignment, which was successful. Attempting IQ Balance indicated an audio level of 0 so could not be completed.

Using a 12.31 power supply (battery) and an external high impedance DVM I performed the following tests...
1) Voltage measurements of IC 10 pins. Pins 1,2,3,4,7,8 all within specs, Pins 5 and 6 higher than spec by 1 and 2 volts (5.94 vdc on each).
2) Resistance measurements on component side around IC10. All seem reasonable compared to schematic-  pin 5 to ground =10k (after cap C24 charged), pin 5 to B+ =10k, pin 6 to pin 7= 119k, pin 3 to pin 7 =0, pin 1 to pin 2 =0.

Without an o-scope I don't know how I can look for the signal from the CW Filter, and don't know how to check that audio muting from Q7 is not on. But most of all, I can't find a reason why pins 5 and 6 are high unless this indicates they are not conducting.

Any thoughts greatly appreciated!!! Kit was built very carefully with each joint inspected after soldering- but yes- "it" happens.

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