Try another cord and outlet.
After that there are no user serviceable parts. But let's say you didn't reveal you were a SpaceX engineer. You would go get the service manual next or try the next link.
The LG TV does not work (the red light doesn't turn on) unless you remove it from the wall plug for a few hours... But when you reconect it it works until i press the on/off switch or disconnect it from the wall plug again, which means i have to wait a few more hours... Please someone know the problem?