Can anyone explain to me why, with Photoshop CC, the default keystroke Shift-F5 (for fill) does nothing with my Macbook Pro but works with my Mac Mini? I have the current version of Photoshop CC installed, but it has been this way with earlier versions for over one year. I checked the keystroke menu for Fill on the MBP and it has the correct keystroke setting for that function.
on a mac, the function keys do not operate by default as "function" keys but control other functions. For example F1 and F2 control screen brightness, f 10, 11, and 12 control volume functions.
There are two options. You can hold the fn key down whenever you want the F keys to operate "normally" (so in your example you would hold Shift-fn and press F5.)
You can also open the keyboard preference pane and set the F keys to operate as standard function keys, and then hold the fn key down to operate the mac alternate control. I think many Mac photoshop users do this as the function keys are used frequently in Photoshop. Most mac programs don't leverage the function keys so the majority of the mac user base get more use from Apple defined setup.
BTW, if you don't use the "fade" function (or rarely use it) which is the default for command-F you can change the keystrokes in Photoshop so command F brings up the fill dialog. That's what I've done as I use the fill function all the time, and rarely use the fade function. (which I've set to Command/Shift F)