MacBook doesn't sleep when closing lid with external monitor attached with Lion

same happens with mine wont sleep if magsafe adaptor and monitor are attached

Just go into sharing in system pref. and uncheck "internet sharing"

makes no difference for me

I just upgraded from Snow Leopard to Mavericks on Saturday and discovered this no sleep with lid closed and external monitor connected issue (one of many OS X annoyances/isssues post-Snow Leopard).

I cannot say if unchecking share printers was a factor, but I did that anyway. What did work was doing this:

--disconnect external monitor

--disconnect power cable

--run this line in Terminal: sudo nvram boot-args="iog=0x0"

--restart

--plug back in external monitor and power cable

After I did those steps I could now close the lid of my MacBook Pro (15" mid-2010) and everything would go to sleep as it did in Snow Leopard.

For those of you just accepting having to manually put everything to sleep, that is settling. OS X only continues to get worse, not better. The peak was OS X Tiger, after that changes for just change sake screwed up Spotlight, Expose, then Safari lost RSS, then iTunes lost Party Shuffle, not to mention crop getting screwed up in Aperture.

Anyway, at least if you are a power user and run Terminal you can get your MacBook to perform sleep like it should. It is preposterous to need to run Terminal for that function.

jk10003 wrote:

I would like to offer this solution. I have a MacBook Pro with an external monitor, and, for a year and a half both displays slept when I closed the MBPS. This behavior stopped when I installed Lion. They would sleep when I removed the power cord, but what a pain that would be. The command "pmset -g assertions" gave no indication of which process ought be preventing sleep.

I contacted Apple support, and after some searching, the guy working with me found this thread, which was flagged as an Apple-approved solution:

https://discussions.apple.com/thread/3190417?start=165&tstart=0

This is the important part:

Correct AnswerRe: How do I tell Lion to disable the LCD screen even when the lid is open?

Aug 31, 2011 9:56 AM (in response to Bob_viking)

Here's the command to make your laptop behave like it did Pre-Lion (courtesy of my friend):

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

Works perfectly for me. If it screws up your system, just zap the PRAM next boot (cmd-opt-p-r) and you'll be back to the default Lion state. Or if you can still get into terminal, this command will get you back to Lion's default state as well:

sudo nvram -d boot-args

Enjoy!

One snag was that I had to run it with the external monitor disabled, but it worked great!

I'm a so-called 'late adopter', only having upgraded to Lion from Snow Leopard this month. Your solution nicely solved the problem for me. A real shout out to you. Thanks!

I have this problem too. Apple's support article on multiple displays (link) describes this behaviour as "closed lid mode", which is only supposed to be invoked if you have an external keyboard and mouse connected. I don't have a keyboard or mouse connected to something isn't right.

There's a dedicated support page for closed lid mode: link

I hope terminal commands aren't the only way of resolving this problem.