A:Answer If by Comcast HD box you mean the cable box, then no, there would be no reason I could conceive of that you would ever want to attempt to connect a player to that box. The Samsung smart player has no ability to record and is only setup to output a video/audio signal. If, on the other hand, your Comcast HD box has multiple HDMI inputs (meaning those inputs are intended for accepting signal from other sources) to such extent that it will function as a video hub, then there may be some reason you would want to connect it to there. To do so you would simply use an HDMI cable and ensure that it is connected to an HDMI in port on your Comcast HD box. To be clear, I dont know if Comcast makes any type of box that functions in this way. Check with Comcast.