Screen flashes. My Vizio P4 46" plasma is flashin like a strobe light with a green color in the

Question

My Vizio P4 46" plasma is flashin like a strobe light with a green color in the backgroud. You can still see the picture at times but not a clear as it originally was. Another strange thing is when watching with Comcast I can hit the "guide" or "info" button and it will clear up momentarily. Anyone have any ideas. I also can't seem to find a repair manual anywhere on the internet.