I would think the tv is a few years old? Disconnect the set from AC power, then press and hold the power button on the TV itself (not the remote), for 10 seconds. After another minute, plug the set back in and press power once. Do you still have the same problem.
If the TV still does not power up, then there is a short inside the set stopping it from fully powering up.
It is most probable that there is a failure on the power supply board inside the TV. Commonly the capacitors on this board will receive a surge and then fail. They can sometimes be visually verified by removing the rear of the set and inspecting them for bulges or leaking fluid at the top or the base of the caps. This is the most common mode of failure for these sets.
The capacitors are located on the power board inside the set, where the AC cord plugs into power board.
flyatyou66, May 2014
