HT3131: Mac notebooks: How to use your computer in closed clamshell (display closed) mode with an external display

Learn about Mac notebooks: How to use your computer in closed clamshell (display closed) mode with an external display
Lindberg
Level 1 (7 points)
Mac OS X

Q: Clamshell Mode Doesn't Work after Upgrade to 10.8.2

After I upgrade to 10.8.2 yesterday, my MBA doesn't work in clamshell mode.  As soon as it is waken with USB keyboard, it turns itself off in a few second.  I need to leave the display open in order to use the external display.

MacBook Air (11-INCH, MID 2011), OS X Mountain Lion (10.8.2)

Posted on Sep 21, 2012 12:12 AM

by Chip a Dee,Solvedanswer
Chip a Dee Chip a Dee
Level 1 (10 points)
A:

Guys there's a pretty simple solution to this, well it worked for me anyway. Since Mountain Lion it seems that sudo command no longer works for keeping your mac lid open but screen off and only using your external, also it now causes the external monitor to keep cycling in and out of sleep mode.

 

So to be able to use your external while in clamshell mode as normal type this sudo command into terminal:

 

sudo nvram -d boot-args

 

Then reboot, plug your external back in and everything should be fine for using your external in clamshell mode. As for opening the lid back up for better airflow while using the external it seems the magnet trick is the only work around I can find at the moment.

Posted on Oct 8, 2012 6:57 AM

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Lindberg

Q: Clamshell Mode Doesn't Work after Upgrade to 10.8.2

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  • by dranasrid,

    dranasrid dranasrid Nov 19, 2012 6:42 AM in response to Lindberg
    Level 1 (0 points)
    Nov 19, 2012 6:42 AM in response to Lindberg

    Hi everybody..

     

    I think i just found the solution.. 

     

    1) connect the external display (both are working), and make sure the external is the primary display.

    2) use a magnet to shut the internal display off (only the external is working by now).

    3) lift up the magnet and quickly close the lid.

     

    I succeed using the clamshell mode using this method. Hope to hear good news from you all.

     

    Macbook Air 13inch 2011

    OS X 10.8.2

  • by adriangr,

    adriangr adriangr Dec 11, 2012 8:07 AM in response to Lindberg
    Level 1 (0 points)
    Dec 11, 2012 8:07 AM in response to Lindberg

    Hi, I have the same problem with an MBA 11´. I realized the problem arises when the mac is not connected to the electric supply. Once connected it to the power supply and it seems to be working fine now. I also have an MBA 13, and it doesn´t have this problem.

  • by famouswolf,

    famouswolf famouswolf Jan 17, 2013 11:26 AM in response to Lindberg
    Level 1 (0 points)
    Jan 17, 2013 11:26 AM in response to Lindberg

    I tried "sudo nvram -d boot-args" and reboot and it still was shutting off.  Then I plugged in Macbook Air to the external power source and I can now work in clamshell mode without the Mac going to sleep. Apparently the external power needs to be connected for the clamshell mode to work.

  • by fedtho,

    fedtho fedtho May 25, 2015 1:26 PM in response to sjrlexlibris
    Level 1 (4 points)
    May 25, 2015 1:26 PM in response to sjrlexlibris

    THANK YOU for sharing this dead simple fact !!!!!!

     

    I had rewired all my (music) equipment, unplugging everything in the process. I use a dock (Henge Docks, highly recommendable by the way) to avoid plugging in each time I need them all the peripherals I need for my music.

    This dock obviously includes the power connection. When I replugged everything, I forgot (yeah... I know) my MacBook's power supply, and didn't notice because the battery was full and everything else was working.

    It made no sense that suddenly my laptop wouldn't wake up, clamshell had worked less than 12 hours earlier, I was loosing my mind.

     

    I hope my thanks reach you. You helped me avoiding all those surely useful but very scary terminal commands (scary to the very basic user I am.)

    Not trying them was a very good thing as I never use clamshell on battery, so my hilarious "problem" basically solved by plugging in what had always been plugged in...

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