Was the receiver on top of the tv or just below it? Still sounds like a static or magnetic problem if the flyback is ruled out. On the other hand the video out of the receiver may have been damaged when an arc discharged in the TV. I've seen this happen before. Is your system in a dry area? Might want to consider picking up some anti static spray for the carpet or maybe a humidifer. Glad you found the problem! Much cheaper than the TV! And lighter too!! Best of luck!