One day all of a sudden the audio just went on my MacBook Air. I've had this computer since 2010, it was a first gen MBA so I figured I might be SOL. However, I don't give up easily when it comes to computer problems.
The first thing I did was research the problem. From my experience I know that someone else has had the same problem and has posted questions or repairs somewhere on the Internet, to which others have responded.
So after reading a bunch of possible fixes, I figured that I would first try a reformat and rebuild of my computer instead of trying to hunt down some random preference files and the like.
My computer was in bad need of a "nuke and pave" anyway. The HD had bad blocks so I knew I had to reformat and zero out the data in order to move the blocks out of the way. If the reformat failed, then I knew I had to replace the hard drive. Fortunately, it did not.
Plus, the OS was dog slow, so I knew that a clean OS install would help. And I was going to streamline the computer with only the apps that I need to do my consulting work and novel writing.
However, after an extensive rebuilding of my OS and user profile, the 'no audio output device' message (and no audio at all) was still happening.
That led me to believe that I had a hardware problem. So I went back to the Internet and found this YouTube video that explains it all:
So, I did the repair as the YouTube poster demonstrated. His video shows you how to re-seat the MBA audio flex cable and more often than not it works just fine with the original cable.
And it did for a few hours for me!
But then it failed. However, now I was convinced that it definitely was the audio cable. How could it not be? The cable itself was almost 7 years old and sat under the battery all that time.
So I bought a new cable from iFixit, and a Spudger (which I had been meaning to get for a while now), and set about to doing the fix with a new cable.
The new cable comes with some sticky adhesive sheathed in some paper covering along certain points of the cable.
I didn't bother using the adhesives and left the paper coverings. Since the cable was now going to be on top of the batter away from any heat source, why bother?
And there's other paper labels in there anyway and the computer had never caught fire. So unlike the old power adapter issue and the battery issue from the old G4 Macbooks, I think I'm good here.
Anyway, did the audio flex cable replacement, closed up the Mac, and started it up.
As soon as I heard the startup chime I knew it worked.
Now I'm listening to the Game of Thrones soundtrack through my MBA's speaker as I type this.
My advice is this: Before any computer repair professional like the Apple Genius Bar people tell you that you need a new $600 logic board for your aging Mac, go to the Internet and do your research first.
Someone out there knows the answer because someone out there has already had the same problem and solved it.
Most likely you can do the fix or upgrade yourself with a little confidence, the right (inexpensive) tools and hardware, and with the generous help of the iFixit/YouTube/Other World Computing/Etc. people out there who have openly shared their knowledge.
The total cost of my fix was under $30, a far cry from the $600 new logic board, that wouldn't have fix the problem anyway since it was simply the audio cable!