I'm having some strange issues on a used Mac Pro (cheesegrater) that I recently acquired. It seems like it won't recognize USB-drives of any sort. I've had problems with all of the following: Generic USB Thumb-drives, LaCie external USB hard drives aaaaand my iPhone 5. Whenever I connect either of these the OS simply doesn't recognize them and does not respond as expected. Ie: connecting my iPhone 5 (Not jailbroken. Original cable) will not make it show up in neither iTunes nor Image Capture or in any other apps that should be able to see it such as Lightroom. It does charge though. Connecting a Thumb Drive results in nothing.

It makes no difference whather I'm using the USB-ports on the front or the back or the "second-hand" keyboard USB-ports.

Curiously I'm using an Apple USB keyboard which works just fine and plugged into one of the keyboards USB-ports I have a logitech mouse which is also behaving fine, so this seems to be an issue with recognizing USB volumes first and foremost.

I'm running the latest version of Mavericks on a mid-2010 Mac Pro.

Edit: I got a tip on another site that this might have something to do with broken permissions, so I did a repair persmissions in Disk Utility and ran through the maintenance scripts of Onyx for good measure. It now seems like the USB-ports on the back of the machine are working while those on the front are still borked unresponsive.

  • Additional info: Drives and iPhone does not show up in Disk Utility or in terminal with diskutil list.
    – Martin
    Mar 26, 2014 at 22:53
  • This sounds a bit like a missing/damaged driver. Anything weird in the OS setup? Also, do any messages show up in Console when you attach a USB disk? Mar 27, 2014 at 16:10

1 Answer 1


try a pram reset

  1. turn off computer
  2. hit power
  3. immediately hold [Command] [Option] [P] [R]

The computer will chime and then turn off, but keep holding. it will turn on again and chime and then turn off. When it turns on for the third time and chimes you can let go of Command Option P R

Cheers Keoflex.com

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