Laptop audio not working

[DangerIsGo]

So, I'm running ubuntu for the past couple of days, getting the feel of everyday use with it, when all of a sudden today, my sound stopped. It was working fine earlier today. Throughout the day today, the speakers (Z5500's using a stereo cable from the headphone jack) would make a buzzing noise. id turn them off and back on and it'd stop. When I went to play something today, no audio came out. I pulled the headphone jack and audio came out of the internal speakers for a few seconds then stopped. Thinking it might be an ubuntu thing, i restarted and booted windows xp. Same thing. Control panel showed the device as there and functioning properly, but when I go to play an audio or video file, nothing is heard. Any ideas? I took out the mobo and found the chip but there was no cosmetic damage. BTW, I'm using a gateway M275 notebook.