MacBook OSX 10.6.5 No audio after update

Question

Hello, My aluminum 13" MacBook has been fine up until a few weeks ago. The internal speakers do not work after Mac OSX 10.6.5 boots up. I hear the 'gong' on initial start up... but no audio after OSX boots. I have tried plugging in headphones, using a toothpick- nothing works. The sound preferences show 'Internal Speakers' and Built in.
Another interesting fact is iTunes reports "an unknown error occurred -200". Very helpful message.
If I boot into Windows Vista using BootCamp.. audio works just fine. So, the speakers and audio hardware are not malfunctioning. It's clearly an OSX configuration problem.
Any ideas on what I can do to get my audio back? The only thing that has changed was I let Apple Updater install a few patches.

Answer 1

If you have not already done so, run Disk Utility's "Verify Disk" & "Repair Permissions" routines on your startup drive (in that order). If the verify disk step finds any problems, you must correct them before continuing.
Try creating a new, temporary user account. Restart your Mac, logging into that account only. If the speakers now work then something associated with your normal user account is the problem, such as a login item or bad preference file.
If the speakers still don't work with this account, you can delete it. Then try starting up in Safe Mode. If the speakers now work something that Safe Mode disables is the culprit, such as a third party or non-essential extension, an add-on system modifier, startup item, etc.
If none of the above help, try downloading & installing the 10.5.6 combo update. If that doesn't help then you may need to reinstall the OS & update it to the current version.