Previous 1 2 3 4 Next 48 Replies Latest reply: Sep 18, 2013 10:48 AM by veljkobb
shmootz5 Level 1 (0 points)

While the below issue was resolved 100% with 10.8.1 (the same problem  occured back on 10.8), 10.8.2. seems to have reverted to the same  critical bug.


I use the HengeDock (a vertical docking station with the lid closed) with my Macbook Late 2008 Aluminium. When it is in the dock, the Macbook is starting up and shutting down (to and from sleep) when in the external display. The display is NOT broken (and neither is the cable) as it worked fine before upgrading TODAY and I CAN see the Apple logo during boot.


PLEASE help!


Thank you.


PS here is the link to a similar (if not the same) issue from 10.8:

MacBook (13-inch Aluminum Late 2008), OS X Mountain Lion (10.8.2)
  • Jazzyalex Level 1 (0 points)

    Have exactly the same problem and it is really annoying.  Can't work with external monitor as a single monitor to MacBook Air.

  • Jazzyalex Level 1 (0 points)

    There is a solution, which helped me -



    To execute in Terminal:

    sudo nvram boot-args="iog=0x0"

    To undo in Terminal:

    sudo nvram -d boot-args

    Once you type it into terminal I believe you need to enter your password. I then restart my machine. Now the TRICK is to either restart your machine with the lid already closed (hit restart then slam the lid!) OR turn the machine on for the first time (then quickly slam the lid!) once you are past the login screen you can open the lid.

    ALSO: if the machine is asleep, and you simply forget and open the lid, it will wake up both displays. So just remember to wake the machine up with an external bluetooth mouse or keyboard.

  • shmootz5 Level 1 (0 points)

    Thank you for the suggestion. I will certainly try it later today when I am with my monitor.


    Would you mind letting me know what the terminal command does? (In terms of what it changes in the system to make this work, or if I have to use my computer differently at all). Is this something I always leave on (or should I turn it off after Apple does an update in the future)?


    Thanks a lot! Much appreciated.

  • venugopala Level 1 (0 points)

    I noticed simialr issue after moving to 10.8.2 on my hp external display. I was running kernel in 32-bit mode. After making sure it runs in 64-bit mode, all my external display issues are gone.


    To set your machine to boot into 64 bit mode enter this command and reboot:

    # sudo systemsetup -setkernelbootarchitecture x86_64


    In case if you need to go back 32 bit mode:

    //To set your machine to boot into 32 bit mode enter this command and reboot:

    # sudo systemsetup -setkernelbootarchitecture i386


    //To check which mode you’re currently in run this command in Terminal:

    # sudo systemsetup -getkernelbootarchitecturesetting


    I heard Mountain Lion does not support 32-bit mode, but it still allows to set to 32-bit mode, but i don't think it's really running in 32-bit mode.

  • shmootz5 Level 1 (0 points)

    This did not work unfortunately.

  • shmootz5 Level 1 (0 points)

    This did not work either. Thanks for the suggestions though.


    @venugopala, is 64 bit default or is 32bit? I chose your 64 bit version (I believe it was set to 32bit for some reason), but I am wondering which one my computer should be set to. I would appreciate your response



  • venugopala Level 1 (0 points)

    I think by default it is 64-bit. I know in Lion OS i used to run it in 32-bit mode once in a while when some applications run only in 32-bit mode. as long as you don't have any application dependency, it's advised to run in 64-bit mode.

  • shmootz5 Level 1 (0 points)

    It seems you may have misunderstood my issue? The article says:

    "You can still run a single external monitor if you close the lid of your laptop, but that restricts airflow and exposes your display to a lot of heat. Not good."


    ... However my issues is that I cannot use the external display with the lid CLOSED (I haven't tried with the lid open as that requires dismantling my HengeDock, which I will do tonight and let you know)


    I hope that clears up my issue?

  • shmootz5 Level 1 (0 points)

    Just to explain, I have tested my Macbook with the lid open (not in the HengeDock) and it DOES work with the external display. I assume your trick does work @Jazzyalex for the issue where the secondary display does not turn off; however my issue with the display not showing when the Macbook is closed still exists.


    Thanks for your help!

  • shmootz5 Level 1 (0 points)

    Does ANYONE have a solution to this? It is a very annoying issue.

  • z1zms Level 1 (5 points)

    sounds like same issue as this:



    I also have the issue since upgrading to 10.8.2 - very annoying!

  • angelofrombern Level 1 (0 points)

    Same goes for me, Retina, Mid 2012, OS X 10.8.2 (12C54)


    Apple did it again...

  • ltdstylo Level 1 (0 points)

    I have a 15" MBP with an old 30" Cinema Display and Jazzyalex's solution worked for me.

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