Suddenly my tv has no tv signal. Why?

As of last week my Toshiba Regza got a basic cable signal through an existing cable and also through a digital antenna. Suddenly neither work and I get 100% snow. Every other feature on the tv works perfectly. I've tried everything in the menu, double-checked all the settings and the coax connections, and factory reset the tv. Any other ideas would be greatly appreciated as I need my Olympics! Is there a unit inside new flat screens that can just break while all other features work perfectly? Thanks!