I've been having a recent problem with VO on OS X Yosemite where I will have it turned off for a while, and then it won't turn back on. Command+f5 simply does nothing, even when I am on the Finder window (or otherwise logged in to my Mac).
The only way I can get VO back on is by rebooting the entire machine and then pressing command+F5 once I'm logged back in.
Does anyone know what could be going wrong? This is inconvenient at best, and fairly annoying either way.
Just upgraded to Yosemite and Command + F5 isn't doing anything to turn VO off or on. I can however turn it on in Computer Preferences by checking the box.
Go into system preferences and I believe under keyboard there should be a check box labeled something like use all F1, F2, etc keys for hardware or something. It allows you to use the FN key on your laptop or other mac to change the display brightness with the F1 or F2 with the FN key held down.