Unfortunately, I'm unable to assist after the service menu has been accessed. If you can recall if something was changed, you might try changing it back. Otherwise, it may likely require service.
Also, try a different cable input just to test and see if the problem is consistent with a different co-ax input. Maybe something happened to the cable as you were removing it. The likelihood of this happening is small, but I've seen stranger things...
Haven't seen this problem yet. I had accessed my service menu to see how much Panel time was used, after turning the tv back off and back on the cable settings were gone, and I can not acquire a cable signal the VGA output from my computer works just fine, however the coaxial cable does not. Any suggestions would be great.