RCA model RCL3157A no picture

I bought this 27" TV new from Walmart in dec 2011. I was playing my Xbox on it fine. I shut the Xbox off and went to watch tv but the tv has sound only now, no picture. I tried unplugging cables, tried a five minute unplug of the tv, even tried a 3 sec power button push to see if it was the radio only feature. I tried pushing the menu and input buttons but they do not appear on the blackish gray screen. I'm stumped, last resort is the one hour unplug for a "cold start". Zany ideas out there? Tv is only 3 weeks old