Were you attempting to access the service menu?
Recently my samsung LN-S4092D LCD TV turned on into a never seen before white configuration screen with what appeared to be sort of a bios setup. It was not possible to leave that screen without attempting to change one or more settings. I set the resolution setting to 1080i and now I cannot view anything and get the famous "not supported mode" message on the blue screen. My question is does anyone know how to get back to that bios like setup screen so I can change the resolution back to 720? That setting is not in any of the normal setup screens of the television set.