I'm having some new issues with Panasonic TC-P65VT50. I have the December 2012 model. As of last night, each of the 4 HDMI ports will not display a signal (no signal detected, or a similar message). I was watching the soccer game on my Chromecast, then the picture began to distort, and went "black" shortly after and displayed the 'no signal' message. I powered off the TV, tried each or the HDMI ports, unplugged all other HDMI devices, but I can't seem to get any of the ports to work. The VGA/Antenna inputs still seem to work fine.
I'm guessing one of the boards went bad, my guess was the "main board". I believe the model number is "TNPH0988 1A". Does this sound like the right part to replace, based on my description above? Any tips on opening this TV and replacing this board? Unfortunately, the TV is out of warranty.