by gb2 » Fri Sep 16, 2016 4:05 pm
go to System Preferences and click on Keyboard. On the Keyboard tab you should find a checkbox titled "Use all F1, F2, etc. keys as standard function keys - when this option is selected, press the Fn key to use the special features printed on each key." check it and try that. You may have to restart your machine if it doesn't start working right away.