Tony,

I was fairly confident it was the sound card at fault, and the good news is that installation of a new one should not take more than a few minutes. Sound cards, like all electronic components, do take a dirt-nap. I've replaced several for friends that had the same problem, and in each case, the first thing they thought was at the heart of the problem was the speakers. In reality, unless a speaker is overdriven, they rarely fail.

Good Luck,

Gary