Macbook Air without Sound, and missing Input/Ouput device options I have an up-to-date Macbook Air on which the sound no longer works.

I had installed Soundflowerbed on it, and for a long time everything was working fine until a couple of weeks ago when it started to not work after a while.

Then it stopped completely.

I uninstalled Soundflowerbed, reset using:


command + alt + P + R, and
shift + ctrl + alt


but, still the sound does not work.

The Sound devices view look like this:



and, the input devices:





What can I do to get the sound back? I did the hardware tests (pressing D while booting), and there are no issues.

Also, I am pretty sure it is not a hardware issue.

Is there a way to reinstall the sound drivers or something like that?



I did a fresh install, reinstalling the whole system and the sound worked for one day, and now I have the same issue...
Shut down the Macbook 
Press  shift + ctrl + alt and press the power button. Notice the change in power led color if the Macbook is connected to power. Note this won't start the Macbook.
Now, press command + alt + P + R, and press the power button. You will see the screen flashing a couple of times. This won't power on the Macbook either.
Now, start the Macbook normally.
Enjoy!