Does your Slingbox have an internal tv tuner? If so, you need a coax cable to the Slingbox to use the internal tuner as one of your video sources. I don't think it matters which comes first, the Slingbox or cable box as I think they both have a coax pass through. Anyway, from your cable box, you should go HDMI to your tv and component video to your Slingbox. This is how mine is hooked up and it works fine. If you have problems, you can go component to your tv and S-video to your Slingbox, but it won't be HD. With both coax and component to your Slingbox, you can watch tv from your cable box or from your Slingbox internal tuner as a second source.