1: Looking for the display cct board (85-1416-1). Any chance of finding it? 2: I have 3, "C" cct boards (85-1229-3) with problems. Is there some place I could send them for repairs, and how much is it likely to cost? 3: I found that the SB-104A was putting power when keying the mic with the "Mic Level" turned all the down,