I acquired a new HDMI cable to use with my new desktop, which came with an HDMI output. I plugged in the HDMI cable and am currently using it to connect with my monitor, but when I tested with a video, I got no sound. I looked in "Realtek HD Audio Manager" and saw an option for HDMI sound out, but it indicates that it is not plugged in. There is only one HDMI out on my desktop. Where do I go from here?
I found out the problem is in the interaction between my ATI graphics card and my Yamaha RX-V663 AV receiver. There is an extensive thread that discusses the problem and several options for solutions at http://www.avsforum.com/avs-vb/showthread.php?t=1043267. I have "fixed" the problem by running the HDMI cable into my TV and then digital coaxial cable from my TV to my receiver. With this solution I am able to get 5.1 sound. I do not have a Blu-ray drive and so I can't test for 7.1 sound. If you run into this problem, the best solution is to ask ATI to update their drivers to be compatible with your receiver.