How I fixed broken internal audio by zapping pram

Oops. I think I stole my own thunder. It was a serious wtf moment though… by all rights, I really don’t think this is supposed to happen. The worst part of this experience is not the increasingly frantic hour of me trying all the ‘right’ things to fix my apparently dead internal audio, failing, and then feeling queazy about the prospect of having to get a new mac pro right now. That was uncomfortable, but temporary. The worst part is that I can no longer mock people who zap pram in attempts to fix random problems that were never intended to be fixable by a pram reset. I wonder what mysteriously beneficial effect permissions repair has…

To continue the upside-down nature of this post, I should mention that the initial damage appears to have been done by windows 7, which I installed on a dedicated internal HDD via the BootCamp Assistant. It all appeared to be going well for the first couple days (of my Tera blitz, during which I didn’t boot over to OS X even once), but then I bounced back to OS X and was stymied by both a much longer than average boot time, and also… no internal audio. Apple System Profiler didn’t see much of anything:

system profiler window showing a basically empty window where the details of the internal audio device should be

I did several normal reboots, shutdown –> boot cycles, disconnection of various extra hardware and peripherals, SMC reset… but nothing was helping. The first time I booted back to win7, it offered to re-install the drivers. Windows could see the internal audio device (which it believes is of the RealTek variety) and allow me to select it as the default device, but still no actual sound was emitted. I figured it was kinda toasted at that point, but then, not expecting it to work, I zapped pram, and lo and behold:

system profiler window showing normal internal audio device details

Boot time is back to normal, too. Hopefully I don’t need to add any permanent pram cheese to this bootcamp sandwich…

UPDATE 1: oh noes, this is totally reproducible. Basically every time I go from win to mac, the audio device goes away until I zap pram. a bug has been filed.

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