This was a while ago so I may not remember everything, but here’s an attempt. I think what happened was that the monitor’s software or firmware went crazy and stopped talking to the C100. It was camera specific, so the monitor worked with other cameras, just not the C100. Fortunately, I live about 15 minutes away from Marshall in L.A. so I was able to go over there. They reset the firmware, or reloaded or whatever they called it, and it worked again. That’s the good news. The bad news is that it happened again a little later. I’ve been fine for about 6 months now, so I hope this is behind me. If you live close, drop in on them in El Segundo. They were VERY helpful and friendly. If you aren’t local, call them and I bet they will expedite a repair. Hope this helps.