The strangest external hard drive problem...

Discussion in 'Mac Basics and Help' started by itsjustmeee, Jan 10, 2016.

  1. itsjustmeee macrumors 6502a

    Joined:
    Dec 28, 2008
    #1
    This one has me baffled. I have an external 1.5 gig USB 3 hard drive that's worked fine with my 6 month old macbook pro up until a few days ago. When I plug it in, it doesn't mount. As a matter of fact, it doesn't appear at all ... not in the disk utility or even in the "system report" under the USB in About This Mac info or in a new finder window. The drive lights up and I can hear it working but it's non existent. Now here's the odd thing. I can plug it in to my Mac Pro and it mounts fine and works perfectly. I'm using the same cable so that can't be the problem. And yes, I've tried both USB ports on my macbook pro and restarted the computer as well. Would anyone have any possible explanation as to why a drive would just stop mounting and showing up on one computer but work just fine on another?
     
  2. Fishrrman macrumors G4

    Joined:
    Feb 20, 2009
    #3
    Just some thoughts:

    Does the drive have an external "power port"?
    Did it come with a power adapter?
    Do you by any chance have a powered USB hub?
    Have you tried connecting the drive to the MacBook via the hub?

    I'm wondering if this could be a "USB bus power" problem -- in that the drive is drawing more power than the MacBook's USB bus is providing.

    Have you tried an SMC reset?
    Or as stacomer mentioned above, a PRAM reset?

    Are you near an Apple Store?
    You might take the MacBook and the drive to them, and demonstrate the problem...
     
  3. ProjectManager101 Suspended

    ProjectManager101

    Joined:
    Jul 12, 2015
    #4
    Use disk utilities, probably related with permissions. It is just a bug in OSX.
     
  4. itsjustmeee thread starter macrumors 6502a

    Joined:
    Dec 28, 2008
    #5
    Thanks for the suggestions. I ran First Aid in the disk utilities and didn't help. Then I a Pram Reset. That didn't work either. And no, the external drive doesn't have an external power port or has a power adapter. The thing is that this drive lights up and I can hear it spinning. It just doesn't mount or gives any indication that it's even hooked up other than the light on the drive coming on and I can hear it working. Yesterday I bought another external drive ... a 2 TB WD My Passport which works fine. And I've also plugged in a Glyph which also worked fine. It's really an odd thing. About the only thing that's changed with this drive is that I plugged it into my Mac Pro to transfer some files and that computer still has Snow Leopard on it and my Macbook Pro has El Capitan. I'm wondering if there's a bug in the OS?
     
  5. CoastalOR macrumors 68000

    CoastalOR

    Joined:
    Jan 19, 2015
    Location:
    Oregon, USA
    #6
    El Capitan seems to be a little inconsistent with mounting and unmounting USB drives. I had a USB that was inconsistent with mounting. It worked fine with a Mac using Yosemite. I checked it with Disk Warrior and the Directory Optimization was a 3 out of 10. I rebuilt/optimized the directory with Disk Warrior and it has been fine since.
     
  6. itsjustmeee thread starter macrumors 6502a

    Joined:
    Dec 28, 2008
    #7
    When you say "rebuilt/optimized the directory", are you referring to the drive with the OS or the problem external drive? I thinking that Disk Warrior can't work if the computer can't see the actual drive, can it?
     
  7. CoastalOR macrumors 68000

    CoastalOR

    Joined:
    Jan 19, 2015
    Location:
    Oregon, USA
    #8
    The directory on the external drive.
    You could run it from your Mac Pro which can mount and see it. Disk Warrior can also make a bootable USB thumb drive that you can run it from.
     
  8. BrianBaughn macrumors 601

    BrianBaughn

    Joined:
    Feb 13, 2011
    Location:
    Baltimore, Maryland
    #9
    Alternately you could back up the data that's on the drive, reformat it, then replace the data.
     

Share This Page