F10, F11, F12 work as function keys, not volume

You can hold the Fn key while pressing these to evoke the special features, or go to the Keyboard system preferences, then to the keyboard tab, and uncheck the box to use the F1, F2, etc. keys as standard function keys. This will reverse the behavior, so the Fn key is required to issue F1, F2, etc., and the default function of these keys will be the special features (volume, brightness, etc.).

In addition, try checking your keyboard layout in the Input Sources list, and ensure it is set to a standard keyboard layout such as U.S. You might try changing it to something different, such as US Extended, and then change it back to see if this toggles a different behavior.

Hi had this exact problem. I spoke to apple support on the support Chat and they suggested I shut down my computer by pressing the Shift-Option-Control keys and the power button at the same time. I was initially a little unsure about this because I've had hardware problems in the past when doing this kind of troubleshooting. He advised me to press Command, Option, P and R before the grey screen appeared but I after my computer shut down following the first steps, I checked the keys and they worked again!

I had tried a few different options in System Preferences but could find no obvious solution! Hope this helps anyone!

System prefs - keyboard - use all F1 as standard - check uncheck the box.

Hi,

Same problem. I just upgrade to El Capitan.

My F1, F2, F3 ... etc and most importantly F10, F11 and F12 (volume keys) function as shortcuts for mission control. Why would this be default for when upgrading.

I restarted my iMac using cmnd option P R keys and nothing.

I tried configuring my keyboard settings, and can't seem to find "use all F1 as standard - check uncheck the box.". Super weird. Please advise.

Had the same problem.

Thank you! That's it!

I have the same problem. Have you solved this problem?

Cesar Benito

I have the same problem. Have you solved this problem?

Following the following suggestion. It worked for me.

http://davemeehan.com/technology/how-to-reset-an-apple-wireless-bluetooth-keyboa rd-mouse-or-trackpad

Hi. Try going to system preferences, then sound then select a device for sound output to headphones as "name" and headphones port as "type." Go back and test your volume keys.

This solution worked for me. I did exactly as instructed above by shutting down first with Shift-Option-Control and power button. Then I rebooted with P and R keys pressed and bingo all is fine once again. No matter what settings I redid or toggled in the keyboard preferences, nothing worked—including resetting the preferences.

Doing this reboot restart sequence did the trick.