Yosemite: Turning off Macbook Pro screen (lid open) with external monitor connected

Here is the simplest way to turn on/off any monitor you have connected to your Mac. Enjoy!

https://github.com/Eun/DisableMonitor/releases/

Unfortunately DisableMonitor just turns the screen to black screen, it doesn't turn the monitor off.

Hello, I managed to turn off macbook pro display with the command posted in this thread and keep the lid open(sudo nvram boot-args="

niog=1

So I figured out that there must be another posibility to turn off the display with a sort of command like in yosemite,or with a third party software. Please let me know if you know how to do it. Thanks in advance!

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. 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.

kkwan77, many thanks for finding out the answer and sharing it with the community.

Before trying it, however, I have a question: one ou typed "sudo nvram boot-args="iog=0x0"", what happens to the build-in screen if you unplug the external display?

Would it keep off or would it turn on? The only way to turn it on again is by typing "

sudo nvram -d boot-args

I know this is old but I am able to turn off the display on my mac by turning the brightness all the way down with the F1 key.

Unfortunately the terminal command option doesn't work for me - at least not in the way I want it to. This only works until the Mac is put to sleep - when it wakes up again the internal display comes on too.

I'm an artist using my Macbook pro to run an external display tablet which I draw on. I use the Mac for reference materials or perhaps to watch netflix while I'm drawing. The external display (Wacom Cintiq) does everything else. So sometimes the Macbook screen is just on for long periods of time doing nothing while I'm drawing, and I want a simple way to turn it off and back on again without having to shut the lid/reboot etc. I wish Apple would include a software option for this!

I used the magnet and BOOM it works. Now i am able to use only my External 40 Inch LED TV as my monitor.

Thanks a lot for the solution. I will try the terminal option too. Lets see if that works without magnet, as magnet is a risk, by mistake if i close the lid it may damage the screen....

Thanks anyways for a gr8 solution....Apple is all about Magnets.....

Magnets are already inside the device. If you place a small, weak, magnet in the position of the sensor (see this post by spudnuty on how to find the sensor position: Re: Turning off MacBook Pro's display when using an external display?), it will do no harm. It simply replaces the magnet in the display that goes into that position when lid is closed.

I find the magnet solution to be far less annoying than the solution that requires nvram modifications and then every time you want to activate single-display-open-lid mode requires rebooting while closing and opening lid.

I am currently using with lid closed as it saves my desk space. I have kept MBP on my keyboard drawer below desk. Theres sufficient air flow and hope it does not super heat the MBP to burn all components.

Mostly i will be using MBP for video editing. Please suggest a better solution.

Using magnets did helped but then i have to keep my MBP lid open and its no good to keep it open to attract dust and tablr space.

Its really a problem.

My windows tablet has a disconnect display option in display setings and i keep my tab on this keyboard drawer below desk with tab flip cover closed. Display remains blank. And only display is my TV set.

Hope we had such a disconect display option in the settings in MBP...

EVEN my android tablet works same way.

Please let me know keeping lid closed is there a better way to manage heat. Can i connect a usb fan to blow air outwards from this drawer area like an exhaust. Will it help guys.

Normal usage i have noticed that MBP is not heating up much.

I don't see how it is any different from the magnet already in your mac. When you close the lid of the mac, that is how it knows the lid is closed. Because when the magnet that is built in to the display of your mac comes close to the base of the computer, it triggers the switch, which tells the computer that the lid is closed so it should turn off the display.

By placing a fridge magnet on the same spot of the computer you are basically simulating this without actually closing the lid.
There is no harm here. Just don't use a powerful earth magnet. A weak fridge magnet is all you need.

Actually keeping the MBP lid open helps with keeping it cooler by allowing more air circulation through the top of the keyboard and tiny holes near the base of the hinge when it is open.

having just purchased my lovely new Hengedock Horizontal I was frustrated to find that cooling was abominable with the clamshell closed and it doesn't look like there was any attempt to try and force additional air around the base (although form what I've read here it doesn't seem to work anyways).

Thanks for the magnet workaround - it's gone down a treat. Not being sure where to find small, powerful magnets, I had a brainwave and grabbed my MagSafe 1-2 adapters from Apple. I found one wasn't enough o trip the sensor, but 2 is. They need to be "upside down" which is to say the MagSafe2 connecter facing upwards. Placed roughly 2/3rd of the way down the left hand speaker and the internal display is switched off. Agree, it's something that Apple should enable in Display Preferences if possible.

The whole reason for doing this was power/cooling/longevity/noise - so what's the ideal setup?

Test system: 3x HP ZR2440w 1900x1200 displays, MBPR 15" mid-2012 with GeForce GPU set to auto switch, clamshell OPEN is a room of roughly 24 degrees C ambient temp

Here's what I've learned

- with 1 external display, (TB/DP) the GPU package draws roughly 0.21A (according to iStatMenus) - fan speed ~2000RPM

- with 2 external displays, (TB/DP+TB/DP OR HDMI) the GPU package draws roughly 0.41A (according to iStatMenus) - fan speed ~2200RPM

- with 3 external displays the GPU package jumps to 1.2A, the resultant spike in GPU core drives the fans up to ~3500RPM

- with 4 displays (3 external plus the internal) the GPU jumps marginally to 1.3A and the fans hit roughly ~3700RPM

* i didn't allow a lot of time for components to "settle" between tests and to be fair, I wasn't running anything in the way of "serious" apps although TimeMachine kicked in part way through the test at the same time as fan speeds quickly reached 4200RPM giving me the sense that with 3-4 displays the tolerances for additional thermal stress with increasing workloads is marginal and the cooling system as a whole was stressed.

All of this still compares favourably to running the system CLOSED where fan speeds rarely dropped below 6500RPM

Conclusions

- the best outcome from a thermal stress and noise standpoint is to run your laptop as a laptop with it's own internal display! :-)

- if like me you need/want more display real-estate, then 2 external displays appears the ideal compromise between ergonomics, flexibility and thermal stress

- whatever you do, run it open (magnets are your friend, remember your Macbook is already FULL of them and is DESIGNED to have them in close proximity at certain points on the chassis, just don't go overboard)

Next steps

I'd like to learn how more modern MBPR 15" systems respond with their more powerful and I would hope, more efficient, embedded and discrete graphics chipsets. If anyone has the time to run a similar test, it would be great to know if it's time for an upgrade :-) (any excuse to convince my wife that it's time!)