No sound Early 2014 MacBook Air A1466

[razorwoods]

Working on a MacBook Air A1466 early 2014 with no sound output. It chimes when you reset the PRAM but after it boot it has no audio and the sound icon is greyed out. In the system preferences it reports there are no output devices. Does not output to the headphones when plugged into the I/O board either. Also verified that booting from a known good external drive loaded with El Capitan has the same NO AUDIO issues. Pointers on where to start looking on the board for issues ?

 

[razorwoods]

Forgot to mention that I ran the ASD 3S156 on this unit and it passed all tests.

 

[2informaticos]

Almost all the time I faced with this issue, it was fixed after deeply clean of headphone jack.
YouTube has some videos about that...
If that doesn't solve your problem, try another LIO board.
Be sure to have the correct LIO model.
LIO board with camera connector doesn't match your machine...

 

[JohnB8812]

Almost all audio is on the DC in board so try a known good DC in board and flat cable. If

 

[razorwoods]

Changed the IO board with one we thought was good and that threw us off for a bit. Ordered in a new one and that resolved the problem.