I sure hope someone can help a Newbie. I have an older rear projection Samsung 53" (PCJ534), with 2 Component inputs on the rear. I am just getting into HDTV, and have a question. When I connect the Cable TV set top box ( HDTV Scientific Atlanta 8300HD) to the Component Input marked TV, I get a "No Connection" response when trying to change sources on the TV, and cannot get any picture. When I move the connection to the DVD Component in connections on the TV, it works great. Do I have a TV problem, or is this Pilot Error? Is this TV one that cannot accept both DVD and TV Component inputs at the same time?

Thanks for the help