"USB Devices Disabled"

Discussion in 'MacBook Air' started by MSFT, Feb 22, 2014.

  1. MSFT macrumors member

    Joined:
    Dec 14, 2013
    #1
    Problem...

    I plugged in a flash drive (one that I always plug in). Now, every 30 seconds, I get a notification: "USB Devices Disabled--Unplug the device using too much power to re-enable USB devices."

    Thing is, I get it even when nothing is plugged in. And as far as I can tell, both USB ports work.

    I have reset the SMC, no change.

    Anyone have any ideas?

    Thanks
     
  2. Macman45 macrumors demi-god

    Macman45

    Joined:
    Jul 29, 2011
    Location:
    Somewhere Back In The Long Ago
    #2
    Are you using a hub by any chance? A faulty PSU on a hub can produce odd voltages, making even a stick unworkable.

    If you are plugging them straight into the Mac's ports, and have reset the SMC, then it points towards a low volt or faulty PSU in the Mac itself.

    If you can run the AHT ( Apple Hardware Tests) they may help diagnose any issues with hardware,

    If the tests come back clean, I'd be tempted to backup and try a fresh install of OSX

    AHT:

    http://support.apple.com/kb/ht1509
     

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