os X yosemite keyboard volume not working

Try a PRAM reset:

http://support.apple.com/kb/PH14222?viewlocale=en_US

Ciao.

Don't know if this is your issue but I was having the same problem when my Macbook was hooked up to an external monitor. Go to Sound Settings and select "Internal Speakers". That should fix it.

That was definitely my issue. I didn't even realize that my monitor had speakers in it! Apparently Yosemite now supports audio over DisplayPort whereas Mavericks didn't.

Dave.M wrote:

That was definitely my issue. I didn't even realize that my monitor had speakers in it! Apparently Yosemite now supports audio over DisplayPort whereas Mavericks didn't.

Minidisplay ports supported audio from the 2010 model year MBP and later:

http://support.apple.com/kb/ht4241

Ciao.

I was having that same issue and I didn't know what to do because I had no control of my volume. I restarted my Macbook Pro and now it's working fine.

I had the same problem. I am connected to external display via HDMI, the external monitor does NOT have speakers.

For some reason, after upgrade from Mountain Lion to Yosemite - the sound preferences change the output to HDMI instead of the headphone jack or laptop speakers.

The issue was resolved by changing the sound output settings as Thomas has described.

I'm having the same issue. When I use the keyboard to change volume, the volume changes, but the bar icon don't update. I use one external sound board (focusrite saffire pro) and when I try to change the sound source, I have to restart the software. For exemple: If I'm using itunes with internal speaker and I want to use focusrite, I click on focusrite and the sound still on internal, so I have to restart itunes. In this case, until I restart my mbp the volume icon (bar) don't work with focusrtie. In both case, the icon don't update when I use keyboard to change volume.

Sorry for my english and I hope to find some fix to it.

Btw, I have a mbp later 2013 and I installed Yosemite over Mavericks.

Thanks a lot.

***** UPDATE *****

After some research, I found a solution. Use this command on terminal:

sudo killall coreaudiod

It fix my problem, and I think will solve yours.

***** UPDATE 2 *****

The command above fix the problema until you restart your mac. After the restart, you must type the command on terminal again.

I hope Apple should fix this as soon as possible.

Thanks for all.

I have this issue too, unfortunately it returns every day. I'm using external monitors and have two systems installed on my MBP Retina 2013, one system is Mavericks for working, and the other is Yosemite for private usage. Every time I boot in Yosemite, headphones do not react to the volume switches. Neither those on the keyboard nor those on the Apple Earphones itself. I can well hear sound and also the (new) beep tone each time I press a volume button, but the volume does not change.

I tried to change the audio device, without success. Removing Earphones or re-plug them does also not help. The only way I currently can control volume of headphones is using the volume slider in system sound preferences. :-/

Timo,

Do you have Pro Tools installed on your mac? I uninstall Pro tools and then my problem has gone. I don't need to use that command on terminal. I'll wait until Avid found the problem and update Pro tools to reinstall it.

AVID CoreAudio has caused this problem. Remove it and the sound goes back like it was on Mavericks.

This happens to me when I use headphones, and wake-up my computer from sleep mode. I hear no music from iTunes, and the trying the volume control only displays a "no speakers" icon on my screen.

To fix this, I have to unplug my headphones, and plug them back in again. After I do this, the volume control works properly.

I had to disable automagic login in to resolve this same problem on my 2009 13"MBP. Works great now.

Same problem. Did a PRAM reset, checked the Sys Prefs and now had the ability to choose Output as Headphones instead of Internal Speakers. Now it's working. However....my MacPro 2011 sure runs a lot slower under Yosemite. But at least it wasn't another logic board issue. Thanks for the suggestions.

MBP 15'' Purchased Nov 1 (updated to OS 10.10) and at random volume control stops working from keyboard and menu control. I get the volume icon with circle and line through it. I have used the terminal re-set and "Restart" to correct issue, but my question is what is Apple doing to correct this bug 100%. I didn't just purchase a 2K computer new out of the box to have volume issues at random.