1 Reply Latest reply: Oct 15, 2013 9:38 AM by mario49
Johnash Level 1 (0 points)

I have new thunderbolt screen and am connecting to a mid 2013 mba. I have a wired keyboard connected to the screen but the keyboard is never detected on startup. I need to disconnect and reconnect it, then all works fine. Any solutions, this is not a physical usb connection issue?

  • mario49 Community Specialists (3,995 points)

    Hello Johnash,


    Thanks for using Apple Support Communities.

    For more information on this, take a look at:


    Apple Computers and Displays: Powering peripherals through USB



    displays can provide up to 1100 mA at 5 V through the port to which the Apple peripheral or device is connected. This power is available under certain conditions:


    If your Apple computer or display is powered off, no power will be provided.



    If you have a peripheral that is acting unexpectedly—such as not turning on or not being recognized by the computer—the peripheral may require more power than is available. If you have a USB peripheral try one of these options:

    • Use a USB hub that comes with a power adapter.
    • Check that the peripheral offers the ability to connect to more than one USB port at once.
    • Find out if the peripheral comes with a power adapter.
    • If you cannot confirm your device's use with a hub, connect the device directly to the Apple computer.



    Best of luck,