I have a fully working HP Elitebook 8440P,
Nvidea Graphics, trackpad, batterty status, its all working fine.
So was usb... untill i installed the 10.9.0 -> 10.9.4 update.
My usb stick light goes off after the niresh boot screen. The stick, and the wifi dongle just don't work.
For now the solution is: remove the IOUSBMassStorageClass.kext
When i remove this class, my usb stick light keeps on, the storage is not mounted... no wonder... and my wifi usb dongle works.
Can anyone tell me how to have usb working... including mass storage? If i need to provide more info, logs or whatever.. please let me know.