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Not recognize USB disks

781 Views 7 Replies Latest reply: Oct 12, 2013 9:43 PM by BDAqua RSS
all-mac Calculating status...
Currently Being Moderated
May 8, 2012 6:17 PM

My OLD Mini is crazy!


When I plug any Pendrive or External USB disk it is not reconized by OS X, even in USB Informations in System Information or in Disk Utilities app.

However, if I press ALT key in startup, every Pendrive or UDB disk is reconized.

AND if it is bootable... my Mini boots perfectly.


I already installed OS X from zero, and not solved.

Any other USB device works fine, like keyboards, mouse (even wireless USB mouse works).


Anybody has any idea about what could be happening? Thanx!!

Mac mini, Mac OS X (10.5.8), Macmini
  • BDAqua Level 10 Level 10 (114,685 points)
    Currently Being Moderated
    May 8, 2012 9:01 PM (in response to all-mac)

    Hello, yes that is very strange, but boot from your Install Disc & see if it shows up in DU.


    "Try Disk Utility


    1. Insert the Mac OS X Install disc, then restart the computer while holding the C key.

    2. When your computer finishes starting up from the disc, choose Disk Utility from the Installer menu at the top of the screen. (In Mac OS X 10.4 or later, you must select your language first.)

    Important: Do not click Continue in the first screen of the Installer. If you do, you must restart from the disc again to access Disk Utility.

    3. Click the First Aid tab.

    4. Select your Mac OS X volume.

    5. Click Repair. Disk Utility checks and repairs the disk."


  • BDAqua Level 10 Level 10 (114,685 points)
    Currently Being Moderated
    May 8, 2012 9:45 PM (in response to all-mac)

    But holding Option key or c key at bootup can or cannot boot from the Install Disc?

  • BDAqua Level 10 Level 10 (114,685 points)
    Currently Being Moderated
    May 8, 2012 9:55 PM (in response to all-mac)

    Might be time to replace the PRAM Battery, 4 years is close to their lifespan, far less if ever without AC power, & can cause strange startup problems...


  • BDAqua Level 10 Level 10 (114,685 points)
    Currently Being Moderated
    Oct 12, 2013 9:43 PM (in response to all-mac)

    What brand/model are these drives, & do they have AC power or are they Bus powered?


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