Help with coreaudiod no longer running

[Mr E]

Hey guys, new user here, both to the forum and Macs in general.

My problem is, coreaudiod on my MB Air 13.3 2010 no longer starts/runs. I've tried resetting the PRAM and following the usual steps for the seemingly common "missing system sounds"-fix (that's how I discovered coreaudiod no longer running, I had no system sounds).

If I start /usr/sbin/coreaudiod manually from a shell it works, I have system sounds, and all applications I use (so far CS5, VLC, FaceTime, Skype) seem to have no issues with sound at all. Starting it like this doesn't fork it into the background, though, and as soon as I Ctrl+C it, it obviously stops.

I've compared com.apple.audio.coreaudiod.plist as well as any other seemingly related plists (/L/P/A/c.a.audio.DeviceSettings, /L/P/c.a.audio.DeviceSettings, /L/P/c.a.audio/SystemSettings, etc. basically all files referenced by "strings /usr/sbin/coreaudiod") with another equally new and pristine MB Air 11.6 2010, and there are no differences or discrepancies that could account for this problem. I'm not running any 3rd party audio programs/tools/utilities, USB audio devices etc.

This problem surfaced out of the blue, over a week since my last software install or update of any kind. Is there anyone who can help/point me in the right direction? What vexes me is that I can start /usr/sbin/coreaudiod manually and it seems to work fine while it's running.

The MB Air 13.3 is a BTO 2.13 with 4 GB of RAM.

Mr E.

 

[satcomer]

Install the 10.6.5 Combo and see if that fixes the problem.

 

[Mr E]

Right, ran the update, the problem persists =(

The weird thing is when I do sudo launchctl load -wF /S/L/LaunchDaemons/c.a.audio.coreaudiod.plist launchctl responds with "nothing found to load", however, if I load -wF it from inside the launchctl shell, I can then start it with "launchctl start com.apple.coreaudiod" and I have audio until next reboot/awake.

It's not a huge hassle to have to do this, it just seems strange that a relatively untouched system would do this. Any ideas?

Mr E.

 

[satcomer]

Since this is a 2010 then I would call AppleCare ASAP. This is NOT normal.

 

[Mr E]

Hi again and thanks for your suggestions,
AppleCare seemed as baffled as me over the phone, suggesting I send it in or do a full reinstall. I really don't want to, this seems to totally be a software / OS issue and not a hardware one so it should be possible to fix.

Now, it's not super-annoying to have to remember to start coreaudiod manually after every reboot, but something is definitely not right:

[snip]
edge:~> sudo launchctl load /System/Library/LaunchDaemons/com.apple.audio.coreaudiod.plist
Password:
nothing found to load
edge:~> launchctl load /System/Library/LaunchDaemons/com.apple.audio.coreaudiod.plist
edge:~> launchctl start com.apple.audio.coreaudiod
edge:~> ps aux|grep coreaudio
edge 169 0.0 0.1 2451256 3292 ?? S 5:16PM 0:00:13 /usr/sbin/coreaudiod
[snip]

Is there any specific drawback to running coreaudiod under my uid/gid as opposed to the _coreaudiod-user? I didn't su to it since it doesn't have a login shell. It'd be trivial to write a little script/program that sets uid/gid to 202:202 and runs the launchctl commands, but what is really going on here?

Would appreciate any thoughts, explanations and possibly even a solution =)

Mr E.