Chosen Solution
Last night we had a major thunderstorm. Several hours later, the volume went on my tv. I was watching it, the picture on the screen flashed on and off twice and then there was no volume, but the picture was fine. Nothing else in the house lost power and the upstairs tv is fine.
It MAY have been a power surge that killed something but more likely a bad HDMI cable. I had this happen with an Xbox 360 and a new cable fixed it. Edit: Or the input device to the TV is having issues. I also had this happen with an Xbox 360.
