I have an intermittent problem with my SONY big screen. It has a great picture but then the picture goes black, but the sound is still on. When this occurs a small red light, where the volume and channel control is located, starts to flash ( I think 7 times and then repeats). However, when this occurs sometimes the other video inputs still are operational, but not always. For example, it can be on the LD setting and go black, but the video two Input will still show a picture. I have had a TV guy out and I cannot get him there when the problem occurs. Does anyone know what part needs to be replaced or what is going on?