My mom's tv made a loud pop then the screen had muti colored vertical lines. It would not respond to the remote so we unplugged it. Now the strange part. When we turned it back and tuned it to a over the air channel the tv worked. I changed the dvr to another hdmi port and the tv is working but a few hours later it did it again. I don't want to spent 300 fixing the tv. While its somewhat working now I would like to have a part handy if it breaks again. The other post have made a case for the Main board, tcon or the power supply. Can anyone give me a clue which one I really need to change?