Did I fry my onboard sound?

Greetings everyone.

I am using an ASUS P5KPL-VM and I have reason to believe I might have friend the audio chipset. I was messing around by plugging in the output of a mixer amp (http://www.hifi-forum.de/viewthread-268-329.html) to the input of my computer while trying to make some microphone recordings. At one point I dropped the microphone too close to the mixer/speakers, I obviously got this loud screaming noise coming from everywhere, and then the sound of the computer vanished. Only a buzz remains, and the system itself doesn't recognize any of my hardware (device manager list being empty). I tried downloading drivers but that didn't help. Is there any chance to save this? I have no free PCI port so getting a soundcard is not an option.

Sigh...

Thank you all in advance. Help greatly appreciated.