10 Replies Latest reply: Dec 16, 2015 9:11 PM by itsalec
rodrigofromboston Level 1 (0 points)

Dear all,


My Macbook air (late 2011) USB Ethernet adapter stopped to work after I installed Samsung Kies and Android File Transfer. I already removed the apps and the USB continues to not work.
In System Report (About this mac -> More information) in the USB tab shows the device working with no problem, there is no USB issue, I already plugged other devices (USB HD for Time Machine and my iPhone). I also tested the cable and the USB Ethernet adapter and it works fine in other Macbook air.

I tried to remove the service and add it again and it keeps showing Cable Unplugged.

I upgraded my mac from Lion to Montain Lion trying to solve the issue, but no success and tried DHCP and Fixed IP in the config.
Does anyone have a clue of the issue or know a way to reinstall the USB drivers to fix this problem?





MacBook Air, OS X Mountain Lion (10.8.1)
  • rvaro2 Level 2 (310 points)

    Try this:


    Open Network Preferences

    Select the location you will be using

    Select the USB Ethernet

    Click the - sign at the bottom of the left column to remove

    Click the + sign at the bottom

    Interface: USB Ethernet


    Now the USB Ethernet is back... try that and see if it refreshes anything.

  • rodrigofromboston Level 1 (0 points)

    I tried this procedure many times and also tried to create a new location and add the device, but no success.


    Thanks for the reply rvaro2

  • RRFS Level 5 (4,490 points)

    Have you tried cycling both pieces of equipment off and then back on again?

  • rodrigofromboston Level 1 (0 points)



    I tried to cycle both pieces and it didn't work. I also tried a PRAM reset.


    Thanks RRFS

  • rodrigofromboston Level 1 (0 points)

    Problem "Solved"


    First of all I'd like to Thanks the Apple phone support. I really apreciate your attention.

    We tried a lot of stuff ( PRAM reset, Removing USB config, Creating new network location, restoring using the time machine) none solved my problem


    At the end I decided to restore my macbook air from scratch. I don't know why, but Montain Lion Recovery also failed so I was instructed by support to run a Internet Recovery (Command + Option + R). Few hours later my USB Ethernet is back to work.

    Now I have to waste my time copying back my files and reinstall all apps.


    We could define if the problem is the Samsung or Android apps, but anyway I'll not install this crap on my Mac again.

    If you are a Samsung SIII owner like me, install that software in a virtual machine or do not think in sync it with your mac.

  • fairhsa2 Level 1 (0 points)

    I have exactly the same problem, also after installing Kies.


    I DO NOT want to have to wipe my machine to solve it!  Has anyone else come up with a less drastic solution, or any further understanding as to what the actual problem was?

  • Mick_Mul Level 1 (0 points)

    Thank you rvaro2

    This worked for me perfectly.

    My Ethernet stopped working when I plugged the Ethernet in using a thunderbolt adapter.  I got a warning on the screen and the Mac shut down....I guess the equivalent of a Windows Blue Screen!

    Anyway, your recommendation worked, and my Ethernet is back.

    Thank you.

  • Glen.i.Langston Level 1 (0 points)

    I had the same problem, no ethernet lights flashing and no

    ethernet connection.


    My solution was to select the USB ethernet adapter from


    System preferences -> network


    Then select




    In Advanced, select


    Renew DHCP Lease


    Instantly all was OK.

  • juliakstein Level 1 (0 points)

    Thanks rvaro2 - I had this exact same problem. But I didn't install any new programs (at least I don't remember that). It just suddenly did not work anymore. No recognition whatsoever. At first i tried your procedure and did to something wrong, I guess I did not press "apply", so old configuration wasn't actually removed. But then it was so super simple and worked after I was ethernet less for a month and about to go through lenghty visit at mac store. Thanks!

  • itsalec Level 1 (0 points)

    Hi, I was asked to fix a MacBook Air, circ Mid 2013, where the usb ethernet has stopped working, tested new hardware and same connection on other Mac, all worked - found that the issue was in the Microsoft USB Bluetooth adapter used for the Mouse, it was plugged into the USB Mac Keyboard. Once that was removed the Ethernet adapter started to work. Interesting!