No Sound from Speakers with Onboard Audio

This is a new build, so dust is a non-issue. I am starting to think it is a hardware issue, as well. However, there is one more thing which may be behind this.

This is actually the second MSI motherboard involved in this installation. The first one had some non-working USB ports, so I took it back to Fry's and exchanged it for this one. Unfortunately, I can't recall if the sound worked on the first board, because I was focused on the USB ports at the time.

I did not do a clean install when I got the replacement, because I figured it was the same make and model. Is it possible a clean install would help? I did try a 32 bit Vista installation, as well as a virtual XP installation, and sound did not work on either of those.

I REALLY don't want to have to make another trip to Fry's, but or looks like I am running out of options.

Lane

It IS a brand new motherboard, which I got after returning the first one (same make and model) with the non-functioning USB ports. It definitely might be hardware, but I want to rule out everything else before going through the process of exchanging this board yet again.

Thanks, Neo. Tried that, too. It's looking more and more like a faulty board. I'm starting to get a very bad taste in my mouth for MSI