RCA TV Help

[kentwillow]

I have an RCA F35665 TV with 15,234 hrs. on it. Now when I turn it on, I get a message "no useable signal". Have made sure it is on Chan. 4 for the cable converter box. Have sound coming thru on the surround sound system. Have same problem when trying to watch VCR. However, the DVD shows up fine (it connects directly thru a Video jack; whereas the cable and VCR go into the TV thru a coaxial jack).
Have tried a different cable box, and have hooked up directly thru the cable outlet; neither produced any change. The TV has been working fine until this occured 2 nights ago when we turned it on.
My questions are:
Is this a problem with the coaxial input jack; and if so what can be done to fix this?
Are there other possible causes for the problem?
The TV is very heavy (you know the kind - takes two men and a boy to lift it). The nearest repair shop is 45 minutes away from where I live; thus I'd rather not take it to a repair shop if I can avoid that.
Any advice or suggestions would be greatly appreciated.

[kenwooten]

turned tv on and got double imaging of picture what could it be is it repairable?