10086 Views 1 Reply Latest reply: Apr 15, 2009 12:23 AM by Network 23
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.