Thanks for the replies, guys. Yes, I have tested it at home, same results. I suspected a power problem too, but apparently not. It's Tuesday, 4:30 local, and I am going to take the top off and see what we can see. I read somewhere on the forum that sometimes ribbon cables can disconnect, and it seems logical that there might be one between the upper and lower sections of the unit. When we were setting up, when I put it on the floor, one end was already on the floor, and the other end slipped out of my hand and fell maybe 4-5 inches to the floor. Might have knocked something loose, but if a tiny bump like this can damage it, it's not suited for live performance anyway. Very frustrating. I'll report my results. Thanks again!
Mike