USB ports stopped working

Discussion in 'OS X El Capitan (10.11)' started by rubstrol, Apr 10, 2018.

  1. rubstrol macrumors newbie


    Apr 10, 2018
    Got a message a few times:"Unplug the USB device that is using too much power"
    and then,wired usb keyboard stopped working doesn't show on System profile,nothing .
    Is There a reset for USB?

    Mac pro early 2008
    El Captain
    every usb device unplugged

  2. Shadow Jolteon, Apr 10, 2018
    Last edited: Apr 10, 2018

    Shadow Jolteon macrumors regular

    Shadow Jolteon

    Feb 1, 2018
    United States
    It sounds like something may have gone wrong with one of your USB ports somewhere. Do you have any cards installed that add additional USB ports? If so, remove those and see if the problem persists.

    Otherwise, check inside each of your USB ports and make sure there is nothing stuck inside any of them or that none are damaged inside. If everything looks good, blow them out with some compressed air. The next thing you can try resetting the System Management Controller, and maybe NVRAM.

    If the problem persists after this, it's likely just a bad USB port somewhere on your machine that is actually drawing too much power. If it is a problem with the front USB ports, those aren't too terribly difficult to replace. I believe you can remove the front-facing ports and power button and power on the machine with a pad on the logic board, though it's been a few years since I've worked on one of these, and I can't find a page to reference where that would be. If it is one of the back built-in ports, however, that would be a problem with your logic board, unfortunately.

    Edit: Found an Apple repair guide for this machine here on iFixit. Pages 29-31 describe what to jump on the machine to power it on from the MLB, if you want to test with the power button disconnected.

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