I have the 2011 Quad Core iMac, after upgrading to 10.8 I no longer have any sound output devices showing up. There is no red light coming out of the headphone jack, I have already cleared PRAM/SMC and it doesn't help, with that being said, when I hold Command, Option, P, R everyone says "let it go after x beeps" problem is, I don't hear any beeps because the speakers aren't sending sound. I also am unable to hear sound if I plug in headphones, nothing shows up on the Output Device menu there either. I have the ability to adjust the volume (but hear no clicks). Any suggestions?