Disable Clamshell Mode?

I've been hitting the power button and then clicking sleep. This is definitely a First world problem, but I under Snow Leopard I was able to sleep the computer with ext. display plugged in by closing the lid, and that functionality was removed under Lion. Not a big deal, but if there was a way to reenable it, I'd be interested.

If you tried the sudo command I mentioned earlier and it didn't work, read on.

Try resetting your PRAM.

1. Shut down the computer.
2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3. Turn on the computer.
4. Immediately press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.Continue holding the keys down until the computer restarts, and you hear the startup sound for the second time.
5. Release the keys.

After resetting the PRAM, try to run the sudo command that I mentioned below. I can confirm that this command works with 2009 + Macbooks. I do not have any older hardware to test this on as my Mac is a 2009 Macbook Pro model.

Also remember to make sure you spell everything correctly and that you enter your system password correctly. If you type your password incorrectly, the mod will not save to the PRAM. It is the same password that Lion will prompt you for when installing new software and other things wanted to change data on your Mac.

I tried it again but to no avail... My Aluminium MacBook (late 2008) doesn't respond to it. Do you happen to know if I can check somewhere whether or not the setting was saved?

I have this problem as well since upgrading to Lion. Even without an external mouse or an external input device of any kind it still goes into clamshell mode when attached to an external monitor.

I found it so annoying that I filed a bug with Apple: Problem ID: 10432717

I have a blue tooth mouse and an external monitor connected, with both on anf funtioning ptoperly, I close the lid and the external stays on, I wait 10 seconds and the extenal blinks, Iclick the creen of the external, then scroll with the mouse to the Apple and click sleep, amd everything goes to sleep. Or I can use it in clamshell mode.

Maybe I'm misunderstanding the problem. But all goes to sleep and stays asleep with every connected and turned on.

I did nothing but pair the mouse

I've also filed a bug with apple. First world problem, indeed M3437.

Luke20333 instructions almost made my MacBook Pro behave like it used to before Lion. Thanks for the info, really appreciated it!!

But I think there's a little mistake in the instruction. It didn't work for me at first, but with a little googling I found the one that did the trick:

instead of:

sudo nvram boot-args="iog0x0" (step 2 of his instruction)

I used:

sudo nvram boot-args="iog=0x0" (with a = sign between iog and 0x0)

So, my version of the instructions are:

1. Open up Terminal in /Applications/Utilities

2. Type the following command: sudo nvram boot-args="iog=0x0"

3. Press return

4. You will see a warning about using the sudo command.

5. Type in your password to confirm the command and press return.

6. You should see nothing visible change.

7. Restart your Mac and the Snow Leopard functionality should be restored

Now I can close the lid of my MacBook without having to think if it's connected to an external monitor or not. Much more natural, like what we expect from Apple products...

Thanks for the reply gilbr! I've tried it but it doesn't seem to work for me though... Wich generation Macbook do you have? I have the first 13" aluminium macbook (not pro).

worked for me! thanks peoples.

I have a MacBook Pro 13.3" 2.7GHz Core i7 from early 2011 (Model number: A1278).

I gave up and assigned a keyboard shortcut for all applications, Menu->Sleep, so now I can punch command, option, control, q, and it goes right to sleep.

The reason I gave up was that apparently this behavior (when external display is attached, do not sleep on lid closed), is an Apple-intended behavior, not a bug, controlled in system.kext, where there's a IORegistry Boolean called "AppleClamshellCausesSleep" which is set to "False" whenever a second display is plugged in, set to "True" when no display is plugged in. This is over my head but it has to do with the Darwin/Unix base of the OS and can't be easily modified (at least I couldn't find a way). Even if you were able to modify that Bool to true, from what I read, the display driver checks it upon wake and writes it to False if the external display is attached.

If you're a registered Apple Developer you can download Hardware IO Tools, launch IO Registry Explorer, and look at "IOService:/AppleACPIPlatformExpert/IOPMrootDomain".

I suppose someone with driver programming skills could both edit system.kext and edit the display driver to disable checking/rewriting it, but again, that's over my head.

I understand that some people on this thread are having different sleep issues than what I described above, but for those who wanted to leave an external display plugged in and simply close the MacBook Pro lid to sleep it, this doesn't seem to be possible without some serious know-how (and time).

Great, this has worked, but how would I reverse this so I have it back to normal?

The reason is that there is no gather screens like there was in Leopard, which means that now if you try and wake up the system whilst the laptop is still closed, you have the second screen working, but if you then want to open the laptop screen, you cannot get it to be reactivated until you sleep the system again and then wake both screens up.

Many thanks