Having some trouble with a RTAA 80 ton. I replaced both EXVs and the EXV board. I started getting nusiance trips "EXV failure" on both circuits every now and then. But now, circuit 2 will not run at all. I can run the diognostic and the valve drives both ways. I understand that the EXV board sends out a pulse to test the windings before a startup. Has anybody else had simular faults?