I'm also experiencing this. Quite frustrating.
I'm on 15.04 and GNOME 3.16 with the gnome3-team and gnome3-staging PPA's. Only thing to add this message in terminal every time I hit the non functional brightness keys: (gnome-settings-daemon:13855): media-keys-plugin-WARNING **: No existing D-Bus connection trying to handle power keys -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-settings-daemon in Ubuntu. https://bugs.launchpad.net/bugs/1427877 Title: Media, brightness and volume keys don't work with GNOME 3.15.90 To manage notifications about this bug go to: https://bugs.launchpad.net/gnome-shell/+bug/1427877/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs