If your TV is plugged into a power strip or surge protector, try plugging it directly into a wall outlet; also remove the power cord from the back of the TV and plug it back in, making certain it is plugged all the way in (you would be surprised at the number of times this simple step will correct power-on issues). If your TV does not come on after these steps it will need service.
Hope this helps.
I have a 40' Samsung LCD t.v. Everything was fine. I had playstation running, My computer, as a display board, everything was fine. I shut it down for the night. When I pushed the control buttom to come on nothing. Unplugged everything I had hooked up and ran straight cable from satalite box to tv. Nothing, later in the day I noticed a red light blinking on and off. and a white light building up and going off under the samsung logo at the bottom of the T.v. I thought it might be a standby light now that has gone off and the system is totally dead. Any help would be appreciated.