Not too uncommon. I have seen it a couple of times where you have different cables and adapters (sometimes different ground potentials) let the smoke out of components.
The sound card is onboard, meaning it is integrated into the motherboard. You got lucky if sound was the only thing effected as it is possible to toast a motherboard in your situation. From your description, I am going to assume physical damage to the sound card/audio chip and skip to replacement.
You have a couple of choices, PCI-E, or PCI soundcards. Your board has both slots.
Choices PCI (the white slots on your motherboard): http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100009293%20600011977&IsNodeId=1&name=PCI
or PCI-E 1X (short black slots): http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100009293%20600011982&IsNodeId=1&name=PCI%20Express%20x1
No real advantage of one type over another. They are easy to install. Go into the BIOS, disable onboard sound. Pull the side cover, free up a backplate space, insert card into the free slot and follow install directions. Literally a 5 minute job, if you take it slow.
I didn't cover any more diag/repair steps above. Once in awhile you run across a capacitor that pops, and it is an easy fix if you are handy with a soldering iron and not afraid of pulling the motherboard. It looks like there are 3 little filter caps near the audio I/O, so if you see a little metal case rolling around in the bottom of the case, you know where it came from. By the time you figure in labor, it is usually a losing proposition from a monetary standpont to fix it instead of just replacing/adding a soundcard.
Edited by dpunisher, 14 August 2011 - 07:27 AM.
I am a retired Ford tech. Next to Fords, any computer is a piece of cake. (The cake, its not a lie)
3770K @4.5, Corsair H100, GTX780, 16gig Samsung, Obsidian 700 (yes there is a 700)