no sound on macbook air

I had this same issue off and on for over 2 years. My Apple TV assumed the sound from my MacBook Air and essentially made all my sound options "greyed" out. The only way I could listen through my MacBook Air is to use Apple TV and watch and and listen through the TV. I then used bluetooth to connect to another speaker source "bose" and then my sound options came back to my computer. I spent hours on the phone with customer service and no one could figure out the problem.

I now have full sound back to my computer. I think Apple TV causes an interference with the sound once they are connected. Even when I used my computer at other locations I still had same problem. It wasn't until I connected with another bluetooth source that I was able to gain sound control again. Hope this helps, I was a week away from buying a new computer!

Hopefully one of these steps should solve the problem.

1. System Preference > Sound > Output > Internal Speakers

Make sure Mute is not enabled.

2. Remove the headphone.

If you see red light in the headphone port, plug the headphone

in and out of the port 5 or 6 times to flip the microswitch inside.

Sound output may be stuck in the digital mode.

3. Reset PRAM. http://support.apple.com/kb/PH4405

4. Reset SMC. http://support.apple.com/kb/HT3964

Choose the method for:

"Resetting SMC on portables with a battery you should not remove on your own".

5. Applications > Utilities > Audio MIDI Setup.app

Audio Devices window

Side Bar

Click the Built-in Output.

Under Mute any of the boxes checked? If so uncheck it.

Best.

My audio and facetime camera just stopped working after I installed the latest security update earlier today. Nothing i have done is making them work again.

I got a tip from a colleague to install the 10.8.3 combo update (versus the app store one) and it fixed everything :-) http://support.apple.com/kb/DL1640

Thanks, the "Reset PRAM" part solved my problem! Very grateful for your help!

Thanks dominic23, resetting PRAM not only solved my audio problem but also solved my browsing problem too.

Thanks so much - resetting PRAM did the trick.

My Macbook Air has been without sound for a few weeks. It's only a couple of months old. At first the sound problem was intermittent and then restarts stopped working. Before resetting the PRAM and SMC I checkout Applications > Utilities > Audio Midi Setup per Dominic23's suggestion. His directions were:

Audio Devices window

Side Bar

Click the Built-in Output.

Under Mute any of the boxes checked? If so uncheck it.

None of my boxes were checked, however, I clicked the gear button at the bottom of the sidebar and clicked "Use this device for sound output" and the sound came on immediately.

This was super annoying. Thank you Dominic23 for pointing me in the right direction.

I had the same problem but when I restarted my macbook air, the sound started to work again! Maybe all you have to do is just restart your device!

I had the same problem and resetting the PRAM worked great.. Thank you so much ;o)

I was super frustrated. But all I had to do to fix my sound was go to: System Preferences/sound/output and then select a device for sound output. Then I selected internal speakers. Then my sound worked again. I think after I used my headphones it deslected my sound settings.

Hope this helps others.

Thanks. Resetting the PRAM solved it

Reset of PRAM worked.

tried to replace a known-good i/o board.