For example, if the above option is enabled, press Fn-F10 to toggle mute on or off. To use the features shown on the icon printed on one of these keys while this option is enabled, press Fn. With this option enabled, the top row of keys will act as standard function keys (F1 - F12) and not perform special functions such as volume control. Mac OS X: How to change the behavior of function keys Please use the following article as a reference and let me know if you need further assistance. Are any of the other functions on the top row (function keys) such as screen dim or brightness (F1 and F2) working? If none of the function keys are reacting to what you would expect them to do, I suggest making sure they are not selected to be used as standard function keys (make sure the box is unchecked).

I understand that the keys for rewind, play, and skip are not functioning on your built in keyboard any longer. Welcome to the Apple Support Communities!