1 Reply Latest reply: Apr 15, 2009 12:23 AM by Network 23
augambit Level 1 Level 1
Hello all,

I really want to find a way to turn off the auto sleep when I close the lid on my MBP.

I recently switched over to a beautiful MacBook Pro from a Windows based PC laptop. My PC laptop had a setting to turn off hibernation when the lid is closed. This allowed me to move around in my environment without trying to balance the laptop in awkward ways with the lid half open. Plus I just liked being in control of when the computer is changing its power state.

I’ve done some research on the topic. Seems there is a program called Insomnia that might allow me to achieve what I want, but some of the people on other forums seem worried that the laptop may over heat and burn out. I really don’t know much about Macs, but I can’t seem to find a vent any where on the case, so the overheating problem seems like it could be a valid concern.

Some people also noted that my MBP is capable of running in ‘clamshell’ mode, so I shouldn’t be worried about operating it with the lid closed.

I thought I would bring this topic to the official Mac forums to see what the hardcore Mac folks think of the situation.

MacBook Pro 17', Mac OS X (10.5.6)
  • Network 23 Level 6 Level 6
    Mac OS X
    It isn't a venting problem with the case. The computer can operate indefinitely with the lid closed (which I have done); Apple even provides instructions. There is a huge vent running along the entire back edge of your computer but it is partially hidden by the hinge.

    The problem that you'll see in those instructions is that Apple requires at least a power cable to be physically attached for lid-closed operation, so you can't run it closed without any cables, and you can't keep it awake while the lid is being closed. This rules out walking around with it closed and running.

    I'm not saying I agree with it, but that seems to be the thinking. They use the cable requirement to prevent the possibility that a running but closed laptop will be placed into a case or bag that is then closed, causing a zero ventilation condition and overheating. They're definitely not against lid-closed operation, they're apparently against the possibility of lid-closed operation in a bag.

    With the older lid latches, a Mac laptop could occasionally pop open in a bag and wake up. This did heat up the machine and often caused instability and crashes while in the bag. You'd pull it out and discover that it was hot, and appeared to be running, but (in some cases) the screen was blank and wouldn't light up, and you'd have to force restart it. For this reason I disabled wake on open, which is easy to do in the Terminal. (So you open the lid and then press a key to wake.) But there is no Apple-supported way to disable sleep on close, unfortunately. I've never tried Insomnia but it could solve your problem, as long as you make sure there's room for air to flow around it.