Symptoms. My second hand TV (I traded it for a memory card and micro SD card reader) would not come on by either the remote or on switch. It would not light up or make any sounds.
Diagnosis: The diagnosis was that the TV was not receiving any power. After trying different wall outlets, and plugging in known working appliances, I ruled out that it was not a faulty wall outlet. (I would use a lamp but that doesn't work either). No sense in cracking open a TV and risking your life if the wall outlet is not working or not on at all.