Are you talking about/do you have a TV (with tuners built in) or a display/monitor (you connect everything to it, through set-tops or a A/V switcher)?
My "display" (a HD FPTV) has no outputs. I run everything, including all set-top boxes into my Yamaha A/V unit and the only thing my display gets is one monitor out cable fed from the Yamaha via a hidden wall run and ceiling outlet..
In fact, I just looked at my HD UltraVision RPTV in the bedroom (its about 5yo or so) and it too has no outputs.