Macbook Pro.[Mid-2012] Sound isn't working
Something killed your coreaudio drivers, or the sound hardware/motherboard.

I would suggest to do following order of investigation (Fixes)


Open Activity monitor and look for following: (use sort by "Audio")




If found use terminal to reset the coreaudiod

sudo killall coreaudiod



Copy/paste following in Terminal to find out if the audio drivers are loaded

kextstat &gt; ~/Desktop/kexts.txt


That will output a text file to your desktop. Use any text editor to search for "Audio"

You should have the

com.apple.iokit.IOAudioFamily   com.apple.driver.AudioAUUC



As reported the result is: AudioAUUC.kext is not been loaded?


Lets try to load it manually using Terminal sudo kextload /System/Library/Extensions/AudioAUUC.kext/


UPDATE: 

Based on new information I would suggest following (still trying to find out why your Audio is not loading in the profile.


Resetting the PRAM. Hold Down Cmd-Opt-P-R


Keep Holding until you have hear the "startup sound twice". If you do not hear the system sound then, you are on mute or your sound card is broken.

To un-mute use sudo nvram -d SystemAudioVolume

Test for start up sound!


If not run ioreg -i and look for the AudioAUUCDriver  &lt;class AudioAUUCDriver, id 0x1000003af, registered, matched, active, busy 0 (0 ms), retain 5&gt; (use Edit - Find AudioAUUCDriver)