Turning off Macbook Display when using External Display on Lion

sudo nvram boot-args="iog=0x0" worked for me on MacBook 5,1 (Late 2008 Unibody) with 10.7.3.

1. typed said command in Terminal

2. Closed lid on notebook

3. Clicked with Magic Mouse

4. MacBook's LCD doesn't even show up now

Do I require a bluetooth mouse/keyboard for this to work? I tried the sudo command route but it doesn't seem to work. I'm tryind to do an opened clamshell mode (lid open but monitor off)

1. Typed the command in terminal, input password.

2. Restart macbook pro

3. Internal monistor is on active during startup.

Am I suppose to close the lid and wake up the macbook somehow while the lid is closed? Or is it suppose to startup with the internal monitor already turned off?

By the way, the internal monitor is set as an extension of the external monitor. Not sure if that matters.

Alright, I found a solution that I think should be documented ASAP.

I'm running Mac OS X 10.7.3 on a Late 2010 MacBook Air, connected to a Samsung T24A350 through VGA.

This solution requires an external mouse.

1. In Mission Control Preferences activate one Hot Corner to put the display to sleep.

2. Connect the external monitor and plug in the power source to your computer.

3. Close the lid and wait for the external monitor to show the desktop after the blue screen.

4. Move the mouse to the Hot Corner to put the display to sleep using the external mouse.

5. Open the lid and voila!

Hope this helps cause it was driving me crazy and I didn't want to use magnets or terminal commands.

Apple, sometimes, you suck (I still love you tho).

Take care!

I think this is the best solution

granted the magnet is faster but it gives me an uneasy feeling.

this answer should be marked as the one that actually solves the question this thread.

thank you so much.

Not working for me.

can't believe its so complicated and this hard to get something so simple

I usually download an episode of something, then plug in the cable to my TV and watch it..

now your saying I need to have a power cable connected, I need to activate ho corners etc etc this is annoying!

If I put windows on bootcamp will it work normal?

Hope someone can please advise, going nuts here trying to resolve external monitor issue....

Have white MacBook that I bought new in January 2007, been working fine with an old external 21" CRT monitor that I used with MacBook lid closed.

Running MacBook with Lion 10.7.4 and have a BookEndz dock.

In mid-May, decided to replace CRT with LCD monitor.

Bought a new ASUS 23" VH238H monitor. Connected it up to my BookEndz dock and it worked fine until the other day.

Before, I was able to open up lid, click on power button and then close lid and my external monitor would light up and then would see Mac boot up normally.

Now, when I try to use the external monitor I just get the message on display 'HDMI No Signal' and then screen goes black.....

Only other weirdness I had recently, is the System Prefs window not opening issue, but fixed that by trashing a pref file and rebooting Mac....

Any suggestions as to how to get external monitor recognized again by MacBook??

Thanks for any and all help.

Oops, my bad....figured it out, must have accidentally pressed the input source button, which is next to the monitor's power button....changed input source back to the correct one and voila! the monitor now recognizes and displays my Mac desktop again.....

🙂

It work but then my macbook went to sleep. To keep it awake I installed insomniax now everything works normally. Also to get the menu show on the external monitor make sure you arrange the macbook screen all the way to the left. With this you can remove the magnet if you want 2 screen to work on.

How rediculous is it, that I have to use a fridge magnet in order to trick the Mac to use only external monitor. What is Apple even thinking? All around the internet people are complaining about this issue and Apple is not doing anything about it. I can just close the lid on my MacBook but that would not be too good for the processor and it will probably melt down quicker than usual. I doubt that Apple wants to have people bring in their MacBooks in for warranty repairs, but they are really not giving people any choices.

I don't understand why people won't enter that simple line in to the terminal instead of fiddeling about with magnets and 12-step alternative methods. It works perfectly; you get that old Snow Leopard-behaviour back. And honestly, if John Gruber is comfortable with changing it on his main machine, then i think you can put all your fears of messing anything up aside. Provided you follow the instructions, of course.

It didn't even occur to me that I could just turn down the brightness on my laptop while in mirror display mode. That seems easy enough, though clearly not as elegant as the different options we have with Windows so you can force the laptop display off while connected externally.

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This works for me and should work for anyyone:

1. Activate "Mirror Displays"

2. Turn the internal screen black

Cheers

The following works for me like a charm on a 2012 MacBook Air and Mountain Lion:

1. With external display and keyboard/mouse attached, boot or wake the machine to a login screen while the lid is down (if powering on, you'd have to open the lid, press the power button, then close the lid back down.)

2. Use the external display and keyboard/mouse to interact with the login screen while the lid is down. At this point, the machine sees that only the external display is active, as you would expect.

3. Select your user account and enter password if necessary. Right after doing it, flip the lid open ... quickly.

Apparently, if you flip open the lid within this little window of time, the machine does not detect that the lid has been opened and therefore does not activate the LCD screen. It remains dark, the way we want it.

I've read through this and a few other threads and would like to ask for some help/confirmation.

I have a brand new MacBook Air 2013 model, 13" display. Just upgraded to 'mavericks' in case that matters.

I want to have

1) the lid open

2) use the built-in keyboard and trackpad (I don't have desk space for external kbd/mouse, and find the built-in ones to be perfectly adequate)

3) use an external display as main display at the display's natural resolution

4) disable the built-in display (and not just darken it - free up the ram, etc).

5) PREFERABLY, though not essential, not have to apply external power to make this work (if I just want to hook up to an external monitor for an hour or so, why should I have to lug the charger/etc)

6) PREFERABLY, though not essential, have the use of the built-in camera for facetime/etc.

I like the idea of the 'terminal' commands to set the boot options in nvram. Comfortable with the concept. But will this keep the built-in keyboard and trackpad working (item 2 above)? And will this remove the need for external power (item 5 above)?

I've tried the 'magnet' approach, but it requires application of external power and also requires use of an external kbd/mouse.

Coming from the windows 7 world, I am a little disappointed that this is such a chore ... but forward and onward ...

Thanks!

Steerpike58,

I'm writing this using my mid-2012 Mac Air with Mavericks in the exact setup you wanted: lid open, LCD off, external display On (and at its optimum resolution), typing with built-in keyboard and touchpad, and no power cord. It works ... I'm doing it right now. Here's how:

1. I did the Terminal command: sudo nvram boot-args="iog=0x0"

2. From then on, I just make sure the lid is down whenever the machine is booting up. Of course you have to open the lid briefly to push the power button, just close it back down promptly. Apparently, it's the positiion of the lid during boot that matters. Once booted, I can open the lid and it stays dark. Having the lid open significantly improves wifi reception as well as keeping the machine cool. Prior to this trick, my machine would occasionally run hot and the fan would kick in, creating quite a bit of noise.

Good luck.

Thanks, Man Bui. I tried it and it works great!

I have one follow-on question and one issue ...

1) is there any way to get into this mode without having to shut down first? I tend to 'never' restart my computer, having lots of programs open at all times. I use 'sleep' almost exclusively. OS-X seems to be pretty good at restarting prior-running apps, and I've installed the various 'session saving' plugins for Firefox and Safari, but still - a restart is a bit traumatic!

2) I've noticed multiple 'virtual desktops' coming into existence. I'm not sure how or why, exactly, nor how to describe it properly, but at this moment I'm stting on my laptop with no external monitors connected, and if I use the 'three finger left/right swipe', I see 4 identical 'empty' desktops. I think this has something to do with the fact that I was testing with my external display using both a VGA adapter and an HDMI adapter, at different times, but regardless I have these four additional 'desktops' that I can't explain (or get rid of ... yet!).

Man Bui wrote:

Steerpike58,

I'm writing this using my mid-2012 Mac Air with Mavericks in the exact setup you wanted: lid open, LCD off, external display On (and at its optimum resolution), typing with built-in keyboard and touchpad, and no power cord. It works ... I'm doing it right now. Here's how:

1. I did the Terminal command: sudo nvram boot-args="iog=0x0"

2. From then on, I just make sure the lid is down whenever the machine is booting up. Of course you have to open the lid briefly to push the power button, just close it back down promptly. Apparently, it's the positiion of the lid during boot that matters. Once booted, I can open the lid and it stays dark. Having the lid open significantly improves wifi reception as well as keeping the machine cool. Prior to this trick, my machine would occasionally run hot and the fan would kick in, creating quite a bit of noise.

Good luck.