No audio after clean install of 10.6.3

[miTunes75]

I have a 1st gen Mac Mini running a 1.66 intel core duo.

After an internal HDD failure, I had no choice but to install the operating system on an external drive I wasn't using connected via Firewire. Installation ran smoothly, and updates ran without a hitch. But for some reason, I have no sound. It's as if sound drivers didn't get installed at all

I have searched and searched online, but can't seem to get anywhere. Has anyone had this issue? Attached are some screenshots so you know what we're looking at here.

 

[Quad5Ny]

1. Reset NVRAM & SMC
2. Open Terminal & Run all the periodic scripts - "sudo periodic daily, sudo periodic weekly, sudo periodic monthly", Repair Disk Permissions, Restart
3. Boot in Safe Mode, Restart, Open Terminal & run "sudo update_dyld_shared_cache -force", Restart
4. Rebuild kext cache - Open Terminal & Type "sudo touch /System/Library/Extensions/", Repair Disk Permissions, Restart
5. Mac OS X 10.6.8 Update Combo v1.1, Repair Disk Permissions

 

[miTunes75]

still not working....

 

[iLog.Genius]

1. Run Apple Hardware Test to see if anything gets flagged.
2. Reinstall one more time - if same result, looks like hardware is to blame and you might be looking at a repair.