I have been using this Sylvania HDTV, HDMI as my computer monitor. It has been working great until I put in a new computer game. Once the game loaded up, the screen went to black and "Does not recognize format" appeared. I removed the game, and got same message..I can hear my computer starting up, has sound, no picture. I attached another monitor and my pc works fine. Only with the Sylvania. Can you please Help?