Why won't my Comcast cable box work?

Why doesn't my comcast infiniti cable box work with my home theater receiver?

• i plug it in to my receiver but the tv will not get a signal from it i know i have it on the right input and the hdmi cable works really good for everything else can someone please help me

• Answer:

  Hello, try running your HDMI cable from the cable box output to the HD tv HDMI input. Then run an optical cable from the Comcast box optical out to the AV receiver optical input. Check the receivers settings to make sure the optical input is active. I know it sounds like an extra cable. but you need two HDMI cables to do the same thing through the HDMI ports and you will not lose any audio quality by using the optical ports for your tv sound.