I have the original 360 without HDMI, so I am using component cables. I turned on my 360 yesterday and had no audio. The video is fine, so I swapped inputs on my TV and still did not get audio. I own a pair of Turtle Beach headphones with an optical input, so when i plugged my headphones directly into the 360 (using the slot on the factory component cables) I had perfect audio. I purchased a new set of component cables today and tested them out, but did not have audio again until I switched to a direct optical feed.
Any ideas what I can do? It doesn't seem like it's a setting or something that has gone wrong.