MacBook Pro Sleeps When Stacked

Yes...possibly a very confusing title!

I came across something that I do not think that I have seen mentioned on Mac-Forums...and thought some folks would find interesting.

So about a week ago I purchased a used 13" 2011 MBP. I already had a white 2008 MacBook (which will be going on Craig's List soon).

Anyway...I use the computers in the same place (on my couch while watching TV)...so naturally the two 13" notebooks stack real nicely on top of each other when not in use. White MacBook is on the bottom with the display closed...13" MacBook Pro is on top (with the display open...but sleeping).

When I first sit down on the couch I always tap the space bar of the computer to wake it up (before I pick it up). Well what do I discover...my "new to me" MacBook Pro isn't waking up properly (no video). I press & hold the power button to force it to shut down...I press the power button again to start it up...still no video (I'm doing all this while the two notebooks are stacked on top of each other).

I'm thinking...ugh Ooo...this used 13" MBP I just purchased has a problem!!! So I do a little experimenting...turns out the MacBook Pro works fine if I have it on my lap...but if I place the MBP on top of the sleeping white MacBook...the 2011 MBP goes to sleep.

I did this about 3 times...same results each time. The MBP works fine on my lap...but had a problem when placed on top of my sleeping white MacBook. Confusing...

So I do a little bit of internet searching...and I find this Apple Support document:

Mac notebooks: Magnets in devices may cause computer to sleep unexpectedly

Turns out some Apple laptop computers display this behavior (sleeping unexpectedly & some startup issues)...both of which I was experiencing.

When does it happen? When stacking laptop computers on top of each other...or placing something like an iPhone or an iPad case under or near the palm rests of the laptop.

What causes it? The magnets in the devices (or the devices protective case with magnets in it) activates the automatic sleep feature of the notebook (like when the notebook is put to sleep when the display is closed).

So the solution. Don't stack notebook computers...or let an iPhone or an iPad with a case that has magnets in it near the palm rest area of a powered up notebook computer (models listed in the Apple Support document above).

So I'm glad there was a reasonable explanation to the problem I was having!

- Nick

Hah! As I was reading this, my first reaction was "Magnets. The body of the one underneath must be triggering a magnetic sensor on the top one and making it think the lid is closed."

lifeisabeach said:

Hah! As I was reading this, my first reaction was "Magnets. The body of the one underneath must be triggering a magnetic sensor on the top one and making it think the lid is closed."

Click to expand...

Yes...you got it exactly! Anyone that has "played" with those magnets...knows that they're pretty strong as well. After all...it's the magnet(s) that keep the display closed/secure on Apple notebooks.

Seems very simple once you know the answer! But before that...I was kind of freaking out!!

- Nick

Amazing. I have never heard of that.

Slydude said:

Amazing. I have never heard of that.

Click to expand...

I hadn't heard about it either...and I was even more surprised to find an Apple Support document...documenting the problem.

I think that it's great to learn something brand new everyday...and even better if it's Apple/Macintosh related!

- Nick