I upgraded my retina macbook pro to 10.9.5 osx and my external keyboard is not working. I'm not 100% certain that the keyboard stopped working immediately after the upgrade or shortly afterwards.
My keyboard used to be plugged into the laptop and the mouse used to be connected to the keyboard (laptop<=keyboard<=mouse) and everything used to work perfectly. Now my mouse works when i plug it directly into the laptop (so mac's usb system isn't shot). The keyboard works when I plug that into an older windows laptop (so the keyboard isn't shot). But the keyboard+mac combo doesn't work when I plug it into either of the usb ports.
The keyboard itself is an apple keyboard!
Looking at the USB entry under system report, under USB device tree, I see this:
USB 3.0 Hi-Speed Bus -Optical USB Mouse -BRCM20702 Hub --Bluetooth USB HostController -Apple Internal Keyboard/Trackpad USB 3.0 SuperSpeed Bus -Internal Memory Card Reader
Any ideas??