Only HD input works on Sony Aquos

I have a Sony Aquos model LC-26D40U, I was using this tv on a Dish Network receiver, non HD. It has 2 composite inputs, a coaxial, and HD inputs. It stopped working completely on one of the composite inputs, I get sound only on the other composite input, nothing on the coaxial input. I tried it on my other Dish Network receiver which is HD and it works fine on the HD inputs.