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Turning off Macbook Display when using External Display on Lion

Before Lion you could turn off the internal display on a Macbook by closing the lid, putting the Macbook to sleep and using an external keyboard/mouse to wake it up. After waking up, the internal display would be off and you could open the lid and it would stay off. This allowed better airflow while using an external display, not to mention saved resources like video memory etc. If you wanted to turn the display back on all you had to do was select Detect Displays from the Display menu on the Menu Bar, or put it to sleep and wake it up with the lid open.


On Lion this function no longer works. Lion will automatically execute a Detect Displays when the lid is opened. I don't want to run Dual displays at the moment, my desk is not setup for this and I don't need it. I much rather have more video ram available when I'm playing World of Warcraft.


I know that not having control over what display is active is a more novice user friendly function, but some of us are not novices, Windows has had for years the ability to disable any display from the displays control panel. Most if not all windows laptops come with a dedicated function button expressly to select the active display (press it external display only, press again, internal display only, press again internal and external mirrored, press again internal and external dual display mode). This can be cumbersome and overwhelming to novice users I get it, but Apple should implement some fix for us gaming nerds. I want to keep my lid open to have better airflow and I want my internal display off. How about and advanced button on the Display Preferences.


Anyone know of any existing workarounds?

Macbook Pro 17"-OTHER, Mac OS X (10.7)

Posted on Jul 20, 2011 10:21 PM

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112 replies

Jul 22, 2011 2:03 PM in response to DrBenru

Thanks to ronaldfromjakarta for a great workaround while we wait for Apple to give us a true solution. I was worried at first witht the idea of a magnet on my computer but a small refrigerator magnet over the edge of my MBP, far from the hard drive, over the optical drive seemed worth a try. I moved the magnet from the lower edge of the speaker grill towards the front edge and in a couple of seconds found the spot where the screen turned off. I then forced a Detect Displays from the Display menu on my menu bar and presto, the menu indicated only the external display.


Seems easier than the previous song and dance of put computer to sleep, wake with keyboard etc, but it is still not a real solution, and we deserve a real solution. I suggest we follow Jonathan UK's advice and post a bug report on http://www.apple.com/feedback/macosx.html

Jul 23, 2011 10:25 AM in response to septi

This workaround dates back to at least 2006. I'm guessing the location for magnet positioning may be similar to then, but I'm personally not keen on the idea of calling Apple support when some problem arises with my MBP and I have to confess that I stuck a MAGNET on it! For this reason alone, I'm inclined to wait for an official fix!


Please keep those bug reports flooding in to: http://www.apple.com/feedback/macosx.html


One old source of the current interim solution:


Re: disable my MB display while using an extenal LCD?


Nov 12, 2006 4:35 PM (in response to eckndu)


If you place a small magnet on the edge of the palm rest just above where the Kensington lock hole is located you can do this. You can leave the lid open all the time but the MB will think it is closed all the time.

Jul 23, 2011 3:04 PM in response to DrBenru

On a Late 2007 Macbook, place the magnet above the Kensington security hole. Since the internal HD is on the other side, this should be OK as long as you don't overdo it. Keep in mind some fridge magnets (especially the printed vinyl kind) may not be strong enough.


Another method may be to use the pmset command in Terminal. Use the command pmset -g to find out your Power Manger settings, including the hidden ones, for the power source you're using at the moment. If you find the line lidwake 1 at the end, you can change this with sudo pmset lidwake 0. Keep in mind this will always disable waking up while raising the lid with that power source, not just when an external display is connected. To change it back, use sudo pmset lidwake 1 or reset the SMC.


I'll agree this is annoying, especially since my MacBook tends to overheat when run with the lid closed (I may have cooked a battery this way) and I'd been dealing with random-shutdown problems when using my MacBook as a DVR with EyeTV.

Jul 27, 2011 10:46 AM in response to DrBenru

Support are quoting Apple's engineers as saying it is "expected behaviour" under Lion for the MBP's internal display to reactivate upon opening the lid, even if you want to use only your external display. A new version of the clamshell mode-related knowledgebase article (replacing HT3131) is due shortly confirming this.


This is despite:


- the obvious temperature-related benefits that were achievable (under Snow Leopard) by opening your MBP lid whilst continuing to output solely to, say, a 27" cinema display
- the waste of energy and inefficient use of graphics processing power in needlessly running two active screens (ie if running your MBP in clamshell mode would otherwise make it too hot and/or noisy)
- the negative longer-term impact on the battery and other components from running the MBP any hotter than it needs to be.


So if you would like to have the previous behaviour restored, please lobby Apple to change how Lion handles clamshell mode. Options available to them include changing Lion's expected behaviour or adding a user-selectable option within System Preferences.


Feedback can be submitted here:


http://www.apple.com/feedback/macosx.html

Jul 27, 2011 11:55 AM in response to DrBenru

Furthermore..

They need to allow for the lid, clamshell to remain up and OFF while you use an external display. My older 2007 MBP cannot properly get a decent STRONG signal for my airport when its closed. The Mbps is obviously slower. My understandig is the antenna is housed within the keel of the clamshell?. Runniung Speedtest 3 times tells me this is the case. C'mon Apple - Give us control over display options like before.. please.

Jul 30, 2011 12:55 AM in response to DrBenru

This magnet Mod is awesome! You can have the benefits of Instant Clam Shell Mode (no sleeping) and having the pre-Lion functionality. I have an early 2009 MacBook Pro and the "sweet spot" for the magnet seems to be on the side where the power switch is. It's at the bottom of the speaker, and the magnet attaches at a slant. I can live with this until Apple decides to issue a fix.


As far as the magnet causing problems, there's a magnet in the display that mates up to the one by the speaker. I don't see this beign a problem. We arew just using a different magnet to initiate Clam Shell mode rather than the one in the display.

Jul 30, 2011 3:26 AM in response to Lady Engineer

Hi,

I have a 2010 MBP, it's on the left border next to the "fn-key" ..

like you can see here:

User uploaded file

But I prefer a little bigger and thiner type of magnet like you can see on the next picture.

It's a part of an magnet-bookmark with paper on it, so it won't damage the display if I accidently close the lid without thinking about the magnet.

User uploaded file


The way you find the posission of your "magnet-switch" is not that complicated.

Because the 2nd magnet is somewhere in the border of your display, just take a little magnet and "slide" arround your display border with it.

But becarefull to not scratch anything. If the magnet is reacting you may have found the possision.

In the case of an 2010 MBP you will find 3 magnets in de display .. 2 on the top border (for holding the lid closed) and 1 on the left side.

So if you have the magnets found, just put your little magnet on the possion on your macbook, were the displaymagnet would be if you close it and see, if it goes into clamshell mode..


!! I am NOT responsible if you damage or destroy something! Do this on your own risk!!!


Btw: Sorry for my poor english! .. 😉

Turning off Macbook Display when using External Display on Lion

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