MY PIONEER GOES BLACK?

PIONEER 50INCH RANDOMLY LOSES PICTURE AND SOUND I CANT TELL IF THE WHOLE SET JUSTS SHUTS DOWN OR GOES INTO TO STANDBY. MAY HAVE TO DO WITH THE POWER SAVE?? BUT I DO NOT KNOW HOW TO TURN THAT OFF AND WATCH TV-WHEN OFF THE SET WILL NOT TURN ON THIS SET IS 6 YEARS OLD AND A HAND ME DOWN FROM MY DAUGHTER I'VE BEEN TOLD LAMPS BUT NO REPAIR SERVICE HERE