weird: USB 2.0 devices not recognized, but USB 3.0 devices work ok
I've got a MacBook Pro 15" Unibody (Mid 2012) that's exhibiting a strange problem. The customer reports that the USB ports stopped working a while back; i.e.: the computer would no longer recognize any of his USB devices. They are all USB 2.0 devices (external drive, MIDI controller, etc.).
I did some testing and confirmed that it does indeed not recognize any USB 2.0 devices. Here's the weird part: the computer works just fine with any USB 3.0 devices that I've tested it with.
I've already tried all the usual quick fixes: reset SMC, reset PRAM, etc.
Of course, the next logical assumption would be that it's a hardware fault (i.e.: logic board). Is it possible for a failed component on the USB bus to knock out USB 2.0 functionality, while still allowing USB 3.0 devices to function normally?
Any advice will be much appreciated.
Is this a good question?