[Chester Stone]

Forest, I had this problem and it turned out to be several problems. First, someone had replaced the breakers with 10 amp instead of 20 amp breakers. Next, the condenser motor on the front A/C had worn out bushings, the 110 volt cable to the control board was loose, and finally, I had to rebuild the control board due to a bad relay. I think your idea of switching the control boards will isolate the problem to capacitors, fan motors or compressor. Then work from there.