Unmodified F4 no longer summons LaunchPad

One solution is to rm ~/Library/Preferences/com.apple.symbolichotkeys.plist and log out and back in. I just tried this and it seems to have restored the binding, no hack like FunctionFlip required. My other special keys all work, too. However, I lost my other customized Keyboard Shortcuts, like ctrl+← for switching spaces Mission Control. They worked after I re-enabled them.

It looks like com.apple.symbolichotkeys.plist is the preferences file, and MacOS works fine if it's missing. After I'd edited my Keyboard Shortcuts via the preferences panel that file was recreated and everything's back to normal except Launchpad launches again. Based on a diff of the two plist files I'm guessing the keycode for Launchpad is one of 118, 119, 64, or 65.

I found this solution on a MacRumors discussion.

To not lose your custom shortcuts, open ~/Library/Preferences/com.apple.symbolichotkeys.plist, look for the key named "160". Edit it as follows:

Then Log Out and back in.

I lost the F4 binding too, and after some investigation I got it working again. It's a bit of a hack, but here's what worked:

1. Install FunctionFlip, a free preference pane to modify the function keys.
2. In FunctionFlip click F4: Launchpad, so it's checked.
3. In System Preferences / Keyboard / Keyboard Shortcuts, doubleclick on the keybinding for Show Launchpad and press F4.

FunctionFlip should not be necessary: it should be enough to set the binding in Keyboard Shortcuts. The problem is by default the F4 key does not actually send the keycode for F4, it sends the magic code for LaunchPad. (Just like F8 isn't F8, it's pause iTunes.) And the Keyboard preferences pane won't let you bind that magic LaunchPad key. FunctionFlip solves the issue by making it so the F4 key really sends F4.

Note that FunctionFlip is a bit tricky. For it to work, you have to enable System Preferences / Universal Access / Enable access for assistive devices. Also there's a "Start FunctionFliip at Login" preference that you probably want to enable.

The FunctionFlip page points to two tutorials for LaunchPad: TUAW and Josh Sunshine's. Same procedure as I describe above.