By chance


2014-10-22 05:41:57 8 Comments

How do you turn off the MacBook Pro’s display with the lid open while using an external monitor on Mac OS X 10.10 Yosemite?

All the previous methods—such as the one’s listed here—that have worked on Mavericks no longer work on Yosemite.

Does anyone know the way to do this on Mac OS X 10.10 Yosemite? Turning down the brightness is not the same as turning off the display as the GPU still sends a signal to the internal display and the external monitor.

These were the terminal commands to achieve this on Mavericks:

Enable

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

Disable

sudo nvram -d boot-args

Anyone know how to achieve this on Yosemite?

8 comments

@thundercats_nz 2019-03-21 16:36:12

Similar to other posts here, I ended up doing this with a fridge magnet. Flexible plastic ones did not work reliably, so I found one with a small (~5mm diameter) circular metal magnet on the back. Hopefully this matches the magnet in the lid fairly well, and won't overload the hall effect sensor, if that's possible.

To pinpoint where to place the magnet, I used this guide:

https://www.ifixit.com/Answers/View/506016/Putting+to+sleep+with+a+magnet

This places the sensor close to the left-hand edge, near the headphone jack.

Waved the magnet over the area and if the magnet is strong enough both displays will turn off and the external one then comes back on by itself. When I lift the magnet more than 1cm away from the case the screen comes back. This seems about right compared to the actual lid.

Hope this helps someone, will post an update if anything goes wrong!

@FrankCJ 2017-01-22 11:18:54

I have a magnet iPhone case, I put it near my old macbook's keyboard, near the ASDF keys, and the internal screen turns off immediately! It's so simple!

Credit to http://www.cultofmac.com/176329/turn-off-internal-lcd-display-of-your-macbook-air-os-x-tips/

Edit: You have to connect your macbook to a power adapter to make this method working.

@Envil 2017-06-13 11:50:26

I like the magnet trick :))

@Freewalker 2016-08-13 19:31:29

Reducing screen brightness to 0 via the keyboard works for me - Macbook screen is totally dark, but the external display is not affected.

@Allan 2016-08-13 21:02:37

Welcome to Ask Different. We like answers to be more than just a single line. Ideally, you want to explain why your answer is *right." It also helps to provide links, citations, and/or screen shots. Please review our help section How to Answer on writing good answers to questions

@Steve Heim 2017-02-08 07:54:12

This works to not have any distractions on that display, but osx still sees it, in the sense that you can still move your mouse and apps to that display, even though you can't see it.

@Freewalker 2017-02-08 17:37:51

@SteveHeim Right - it doesn't disable the screen in a programmatic sense, I see that the original question was concerned with GPU. This fits my need when watching a movie for example.

@chan 2015-08-16 15:35:14

This trick works (make the external monitor as primary one and partially close the lid till display goes off)

http://gizmodo.com/5938452/a-trick-to-make-using-an-external-monitor-with-your-macbook-way-better

@Tetsujin 2015-08-16 15:42:19

While this link may answer the question, it is better to include the essential parts of the answer here and provide the link for reference. Link-only answers can become invalid if the linked page changes.

@prototypical 2015-06-25 00:24:08

Found this wonderful free application :

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

Works like a charm.

@Fred K 2015-12-18 10:15:24

This application reduces the brightness of the monitor to 0, but it remains on! So probably it consumes more. Is there a way to completely turn off?

@Nir Golan 2016-06-14 07:55:24

If you choose to mirror the external display (not add a separate desktop) this should reduce the workload

@Mengdi Gao 2016-12-05 01:41:06

@FredK After the display was disabled, it won't allow me to move the mouse to the disabled display anymore (expected result), turns out it does more than reduce the brightness to 0. At least the expected results are archived.

@Andreas 2016-12-30 16:45:10

@MengdiGao Only if you equate "can't move mouse to" with "turn off display".

@user128876 2015-05-22 04:10:48

Go to screen saver then activate the "display off" in hot corners.

@Shmidt 2016-02-06 06:21:19

Both monitors go offline in this case.

@Alfred 2015-05-11 06:01:32

Finally someone who realized a free app to disable monitors: DisableMonitor (on GitHub)

@Fred K 2015-12-18 10:15:34

This application reduces the brightness of the monitor to 0, but it remains on! So probably it consumes more. Is there a way to completely turn off?

@Mengdi Gao 2016-12-05 01:40:42

@FredK After the display was disabled, it won't allow me to move the mouse to the disabled display anymore (expected result), turns out it does more than reduce the brightness to 0. At least the expected results are archived.

@rwg 2014-11-04 04:27:03

The equivalent command for Yosemite is:

sudo nvram boot-args=niog=1

I've only tested it on my Late 2008 15-inch MacBook Pro, but it works for me. Your mileage may vary.

Source: I read the IOGraphics source code, specifically IOGraphicsFamilyModuleStart() in IOFramebuffer.cpp.

Technical details: We need to clear bit 0 (kIOGDbgLidOpen) in the module's gIOGDebugFlags variable in order to change how it handles lid open events.

Previous versions of the code would set this variable to whatever value iog specified in the boot arguments, or 0x03 if iog wasn't specified.

The code in Yosemite first sets gIOGDebugFlags to 0x43, then bitwise ORs it with the value specified by iog (if it exists), and finally bitwise ANDs it with the bitwise complement of the value specified by niog (if it exists). In other words, iog can now only set bits in gIOGDebugFlags, but the new niog can clear bits. So we specify niog=1 in the boot arguments to clear bit 0.

@chance 2014-11-04 05:14:20

How do we remove this command if it doesn't work?

@rwg 2014-11-04 06:37:50

@chance The same way as before: sudo nvram -d boot-args Or reset the PRAM.

@Fydo 2014-12-14 19:28:53

This works once you boot. But only until the computer goes to sleep. Waking it back up turns the built-in display back on.

@Ryan Heitner 2015-01-03 17:25:01

1) After putting in the terminal command, reboot and close the lid immediately 2) Keep the lid closed during boot up and once logged in, open the lid 3) The MacBook Pro's screen is off

@andreas-supersmart 2015-03-24 11:53:08

@RyanHeitner 3 steps work fine! If you need a solution for sleep&wakeup, please visit OSXdaily-Post with Section "Disable the Internal Laptop Display in OS X Yosemite" a hint to correct wake up procedure. Have fun!

@Ronan Quillevere 2015-06-23 08:53:21

Works on mack book with nvidia graphic cards, potentially need to switch to "better performance" in the Energy Saver settings to switch to your nvidia graphic card (like on my 2009 Mac Book Pro)

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