My son recently gave me a 42" Panasonic TV to replace the 32" Insignia that I had in my bedroom. The Insignia is hooked up directly to cable via coaxial (no box) and after doing a channel scan, I get a surprising number of channels. Definitely suitable for the limited viewing I do in that room. Unfortunately, when I hooked up the Panasonic, I get nothing. It will let me do a channel scan, but there are no results. I'm sure I have the correct input selected. Any ideas on why this won't work?