Why my TV is stuck on standby

@colonel62932 the power LED shows that the power supply provide standby voltage the mainboard. Once the mainboard receive a signal from the IR board to turn on, it signals the power board to do so. In your case, this could be a bad main board or a bad IR board.

Time to unplug it, and to remove the back cover. Then take a look for any obviously damaged looking parts on those boards. Take a couple of good pictures of the boards and post those with your Question. That way we can see what you see and hopefully guide you further,

iFixitでの質問に画像を追加する方法