Comments on: Quickly Enter Clamshell Mode with an External Display in Mac OS X

By: Paul

Paul — Mon, 19 Nov 2012 01:32:39 +0000

Yes if it’s plugged in, it will charge.

By: Raoul Duke

Raoul Duke — Sun, 18 Nov 2012 23:25:54 +0000

Is there a way to charge my iphone while my macbook is closed???

By: Doug

Doug — Thu, 06 Sep 2012 01:13:10 +0000

Thanks João!

I was going crazy for hours trying figure out what I was doing wrong. The power connector is the key! You’d think Apple would put that in their instructions for clamshell mode!

Doug

By: felicitycubed

felicitycubed — Tue, 31 Jul 2012 06:29:52 +0000

Didn’t work for me running Mountain Lion on my Mid-2009 MBP, paired with a Mid-2008 24″ Cinema Display.

What i did do though, with a little tweaking and elbow grease, and i really mean a little, was to modify an April 2010 post by Paul Horowitz, found above in this post under “set the primary display”.

I did as follows:

1) Open Up Display Prefs
2) Bring up your external monitor and click “Arrangement”
3) Deselect “Mirror Displays” if not done so already
4) As Paul Horowitz outlined, click and drag the white menu bar to the external display.
5) For me, the resolution on the Cinema Display switched over to its native 1920×1200, but the pointer still resided on the MBP’s built-in display, in some sort of suspended animation, if i do recall correctly. I think the built-in display lost its menu bar to the Cinema Display, but open windows remained at the MBP’s native res.
6) So, to bring everything in-line, i selected “Mirror Displays” and then deselected it again and the coveted result was finally at hand.

By: ptsash

ptsash — Sun, 29 Jul 2012 07:50:28 +0000

The NVRAM method etc no longer work in Mountain Lion. I found a solution, though:
1) Do a restart, then close the clamshell while waiting for the restart to complete
2) The Macbook will detect the external display during the restart, and will use it as the primary (and only) display
3) Once the restart is completed (with the external display used as primary display, open the clamshell. The built-in display will remain off, but you can now use the keyboard and touchpad. Voila!

By: Justin

Justin — Sat, 09 Jun 2012 23:23:41 +0000

You are correct. I wish there was a terminal command where the macbook doesn’t need to be connected to power when in clamshell mode.

By: Justin

Justin — Sat, 09 Jun 2012 17:24:03 +0000

I use my Macbook Air in clamshell mode all the time (along with the book arc mentioned in this post). One annoying thing about this feature is that you have to have it connected to power at all times. Does anyone know how to do this without having the machine connected to AC power?

The reason, I don’t always want my machine to be connected to power as I’ve heard this is not good for the battery…

By: Jay

Jay — Sat, 09 Jun 2012 15:48:46 +0000

Absolutely correct. There is no threat to overheating with the machine’s lid closed as long as there ventilation around the unit.

By: João Chua

João Chua — Sat, 09 Jun 2012 06:39:06 +0000

Clamshell mode only works on my MBP when connected with the power adapter. And, when I read the instructions for clamshell mode on the Apple site (http://support.apple.com/kb/HT3131), it requires the adapter to be connected. Is it just me, or did this article NOT mention anything about the power adapter requirement?

By: Dekard

Dekard — Sat, 09 Jun 2012 05:05:14 +0000

MBPs don’t dissipate any significant amount of heat through the keyboard. No matter how often that misconception is posted, it’s still a misconception.

By: frankie

frankie — Fri, 08 Jun 2012 20:32:28 +0000

Not sure what happened with my lion, but i can’t activate clamshell mode that easy as before.
If I connect my ext. display when the mbp’s lid is closed and click/press a key, it activates the ext. display as extended, not as a single display [internal screen still detected by OSX and "in use"].
So I need to open the lid, find the restart button on the mbp’s screen and close the lid.
Then the ext. display goes gray and now the internal screen is disabled.
Any quicker solution?

By: Paul

Paul — Fri, 08 Jun 2012 18:58:12 +0000

Not necessarily though it could be, it really depends on the ventilation and how the Mac is situated.

A lot of people report increased speeds using clamshell with games and Photoshop, the Book Arc product page cites a few reviews that demonstrate noticeable Photoshop performance. It’s probably best to use it in a cool or air conditioned environment so you don’t overheat the MacBook in question though.

By: Ryan

Ryan — Fri, 08 Jun 2012 18:50:08 +0000

Isn’t this meant to be bad for the laptop as the fan blows out on the inside ???