I've had my Sony Google 46" tv for a few months and love it. Only problem is when turning the TV on, it defaults to TV, not to the HDMI input it was last on (which is the input for my Comcast HD box). The result is a few seconds of loud snow since there isn't a cable signal before it auto-mutes. How do I set the TV to automatically default to HDMI 4 when turning on the TV? Thanks for any suggestions!