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I have a Late 2011 Macbook Pro 13" (running Lion - OS 10.7.4) which I use with a dual external monitor setup. I have two 21" LCDs that I use as external monitors. One uses the built in Mini Display Port on the Macbook Pro and the other is connected via a USB to DVI adapter (Diamond DVILink).

The problem I am having is with the 13" built in display of the Macbook Pro. I would like it to remain closed and unused (I prefer the dual monitors at same resolution), however I cannot seem to "disable" the display in the display preferences applet. So even though the Macbook Pro lid is closed the operating system still makes use of the display, even though the apple logo on the back of the display is unlit. I have tried to move the laptop screen off out of the way in display preferences but I find when I "sleep" my setup that any applications that remain open move to the laptop screen. This makes it difficult to locate the application windows when resuming from sleep.

Display Preferences

Does anyone know of a way to disable the laptop built in display so it is not seen by the OS when external monitors are being used?

  • Have you installed any software that could keep the display from sleeping? – Gerry Jul 19 '12 at 19:49
  • No I haven't. Also, the display does "appear" to be sleeping as the backlit Apple logo is turned off on the back of the lid. – webworm Jul 19 '12 at 19:51
  • Just to clarify .. I do have the lid of the Macbook Pro closed. – webworm Jul 19 '12 at 19:51
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    The Apple logo on the back is lit by the same light that lights the display on the front; no light from the Apple logo just means that the light is off, same as if you turned the brightness all the way down (to off). It does not indicate display sleep, as the display can (and does) continue to update while the light is off. – iynque Jul 20 '12 at 18:58
  • How does one disable the internal display when the lid is closed? – webworm Aug 3 '12 at 1:33
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Turning the brightness down as suggested above turns the monitor off on my MacBook Pro - mid 2014 model. Keeping the lid open allows better dissipation of heat and keeps the fan noise to a minimum so this is my preferred mode of working.

  • This turns off the built-in display, but does not prevent the cursor from wandering off into it. Does "clamshell mode" prevent that? – Tianxiang Xiong Apr 26 '17 at 20:58
  • yes, "clamshell mode" completely disables that display, so your mouse cannot reach it – Ciprian Tomoiagă May 1 '18 at 8:38
  • adding clarity to this answer. all this does is turn off the backlight to the internal display while the monitor is still active and using CPU/GPU cycles. ie. not the most efficient solution. a much better solution would be to put the mac in clamshell mode while the display is open thus not allowing the OS to recognize the internal display and having much less overhead on the system. – ipatch Jul 30 at 16:12
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You should be able to close the lid and use an USB mouse/keyboard to awaken the computer to only use the external display.

The interesting thing here, is that you use an USB-graphcis adapter too. That software may confuse this process.

I would suggest just using the native graphics ports to begin with and see if you can make it work, and then add the USB-adapter.

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    You may have to remove the DisplayLink software initially. – Thorbjørn Ravn Andersen Jul 19 '12 at 19:58
  • Perhaps your right about the DisplayLink software. I may have to save for a Macbook Pro with Multiple Thunderbird and/or HDMI ports. – webworm Jul 23 '12 at 18:09
  • Do some experiments before jumping to conclusions – Thorbjørn Ravn Andersen Jul 23 '12 at 21:46
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I use a very naive solution on a Macbook Air mid-2012: instead of using clamshell mode (closing the lid), I just press the brighness down button until the lowest level. For my surprise, the lowest level turns off the internal display. I don't know if this works for others models, but it works well for me.

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There's a tool that allows you to disable internal display: https://github.com/Eun/DisableMonitor.

I've been using it with success in the same scenario.

Disclaimer: I'm not a maintainer, so I fear I won't be able to provide support in case of any problems. Please use github issues.

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On 10.6 an earlier, the internal display stayed disabled even after opening the lid. There's a firmware variable that restores that behavior:

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

I don't know if it would help in this case though. You don't have to reboot when changing display configurations.

  • I have seen this in other posts but really did not want to have to reboot the computer each time when switching between external display and internal only display. Perhaps I am wrong, but shouldn't there be a way to disable the internal display completely when an external monitor is attached? – webworm Aug 3 '12 at 1:43
  • Confirmed working with latest Macbook Air (June, 2012). To zap the NVRAM next boot press: CMD-OPT-P-R or reset with "sudo nvram -d boot-args". – meshfields Nov 8 '12 at 0:12
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I have Mac book Pro Retina 13 late 2013 and turning brightness down to the end made my lid off with two external monitors connected one via hdmi another one via thunderbolt port. As @Mikey said closing lid and using external monitors can cause serious heat problem for lap top it's true and i asked apple support directly for making sure. it's better to let it be open and using external monitors.

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