Cannot adjust Sound / Volume

I need a solution for this as well

It seems it just randomly happen to people....

Try resetting the PRAM

https://support.apple.com/kb/HT1379

I seem to be having the same problem on my new 2011 MacBook Pro. The only way I've been able to adjust the volume thus far is to plug an external keyboard into the USB, (due to my French Canadian keyboard), press the 'fn' (function) and 'command' keys at the same time and then press the volume keys. Only then do I see the pop-up volume window on the screen and adjustment bar.

I have the same problem on my 2011 Macbook Pro.

I've been using my computer with my lid closed and on external speakers and monitor and bluetooth devices for days on end and I haven't found a solution.

Has anyone out there found a solution yet?

This was the only place I found so far with the same exact issue I have.

I've had some virus trauma in my life, so my mind naturally goes to "VIRUS!" after any little strange thing happens. I'm pretty much imploding at the moment, so, if you guys have anything, let me know.

Hi, I had the same problem. My solution is to have the system prompt password login for every starting and restarting. See if this helps.

Hey. Thanks for the quick reply. I already do the prompt password activated. And nothing. But even if I didn't, it shouldn't have to be so much of a hassle, y'know?

I'll try taking it off and putting it back on, maybe that'll help. But still...

problem started with me today too..

anyone found a solution yet?

i even formatted my hard drive and reïnstalled the os, now it doesn't find any audio outputs anymore.

I installed the latest updates and scanned with Norton my machine and nothing...

However, like six or seven reboots later it started working fine by itself. I guess it goes away by itself.

Good luck.

Hi this problem happened to me yesterday,

it tried everything that people have suggested such as reseting etc. However after numerous shutting downs and resarting the sound finally came back (about 3-4 times)

It seems to be a problem that just occurs and then leaves, you may just have to wait it out.

This happened to me, where I couldn't uncheck the [mute] box in the preferences panel. Then Apple Support told me to do these startup things and then there was sound and I couldn't adjust it. Then I just restarted the computer and it all worked fine.

This happens to me too. Exact same symptoms, same MacBook I think (Early 2011). If anyone does find a conclusive solution, I'd really love to know what it is. It just started happening. Actually, I don't think it ever happened before I started using Internet Sharing occasionally. Anyone else having this problem and using Internet Sharing?

Had the same problem and just fixed it!!

Try this...

Go to System Preferences => Sound => Output

Select Line Out, or Internal Speakers from the list.

That should do it!

Somehow, it has jumped on Digital Out by itself!