Just another couple of "just in case" suggestions:
- Plug a pair of headphones in to all three jacks, just to see. It probably won't make a difference, but it'll narrow down the search by eliminating the cable and the stereo (or by implacting them!).
- If the jacks are auto-sensing (not likely on a motherboard) then check using the software provided for it that they haven't auto-sensed incorrectly (as I've seen happen often). If so, set them manually.
Best of luck.
- Plug a pair of headphones in to all three jacks, just to see. It probably won't make a difference, but it'll narrow down the search by eliminating the cable and the stereo (or by implacting them!).
- If the jacks are auto-sensing (not likely on a motherboard) then check using the software provided for it that they haven't auto-sensed incorrectly (as I've seen happen often). If so, set them manually.
Best of luck.