Problem with my 25' Toshiba TV sCREEN

Question

I bought a 25"Toshiba TV screen( Model NO. 2560XHE ) from a friend who was going finish some three years ago.Just recently I encountered a problem with this tv screen. There is no indication of picture display on the screen- a complete black out. Upon depressing the switch of the screen, a red light comes on, and after a while a green light (LED) comes on and off. Can you tell me what could be a possible cause of the problem with my TV please ?