Hi there The set +/- knob would not turn anymore so I took it apart and it is the the small electrical board with the control that turns soldered to it. It will not turn at all, it is frozen. Is there anyway I can get buy this electrical part anywhere? It just plugs into the main board. I have looked everywhere. I hate to throw away the whole thing just because of this small electrical part. Please let me know. My email is bdean@wpcsd.org or terpy08@yahoo.com thank you Bill Dean