apple proximity power funkiness

October 21, 2011 6:04 AM

Can proximity between two Apple laptops cause sleep/power-down oddities?

I got into work yesterday and put my laptop down on the tech table, very shortly after putting it down (45 sec-1 minute) on a file folder that I had been using to prop it up the previous day, it shut down without warning. After this happened I noticed that the mix engineer's Macbook Air was under the file folder and moved it.
The mix engineer walked by about 20 seconds later, and I made some comment about my computer being cranky and shutting down of its own volition. He asked if I had put my computer on top of his, and I said that yes, I hadn't seen it there under the file folder. At this point he told me that he's repeatedly had this issue with his daughter's computer when it is placed on top of his MB Air, though usually his daughter's computer (I believe a Macbook) just goes to sleep

Further details that may or may not have anything to do with this:

-both computers were plugged into the same 20amp circuit.

-my Macbook Pro had both its wifi and bluetooth antennas turned on; it was connected to a WiFi network, but there were no bluetooth devices paired to it at the time.

So is he crazy? Am I crazy? Was this just happenstance, or is there something more going on here?

posted by aloiv2 to computers & internet (8 answers total)

oh, I realize this was less-than clear: His Macbook Air was closed and in sleep mode.
posted by aloiv2 at 6:05 AM on October 21, 2011

How thick is the file folder? Could the extra heat from the Air cause your laptop to overheat and shut down?
posted by EndsOfInvention at 6:08 AM on October 21, 2011

So is he crazy? Am I crazy?

You're not crazy, but it's not the power supply; my daughter taught me how you can achieve the same effect with a fridge magnet.

Macs have magnetic switches in the screen bezel and base that tells the OS when the lid is closed so it can sleep. The Airs are thin enough that if you stack them (even with a different Macbook) the closed machine will trip the sensor on the one above it.
posted by mhoye at 6:10 AM on October 21, 2011 [5 favorites]

Seconding the magnets. I was messing around with a magnet a while back and noticed that the screen goes off if I wave the magnet within about two inches of the left side of the keyboard.
posted by le morte de bea arthur at 6:21 AM on October 21, 2011

it shut down without warning

What precisely does this mean. Does this mean sleep mode, or completely off?

If the answer is completely off, then the magnet idea on the lid closed sensor doesn't make sense (in this case).
posted by kiltedtaco at 7:24 AM on October 21, 2011

It did shut down completely, as in powered off. The weird thing was that the little light on the front that lights up when the lid is closed did turn on, indicating that it was on its way to sleep. However, when I tried to wake it it was completely non-responsive, and when I hit the power button (once, not holding down), it gave the startup sound and re-booted.

It's possible that it started by trying to sleep and then my machine which I work too hard on a regular basis just decided to give up the ghost for a moment and just shut down...maybe?

The magnet answer is great for why that happens to his daughter's machine though.

To answer EndsofInvention, the file folder was about 3/4" thick, full of Avery label sheets.
posted by aloiv2 at 7:30 AM on October 21, 2011

Did you move the computer before trying to re-start it? If you didn't, the fact that the front light was on AND the computer did not respond to your inputs makes sense, to me anyway.
posted by Chutzler at 9:19 AM on October 21, 2011

I've had a very similar thing happen to me numerous times. Until I put two and two together, I would occasionally put my MacBook Pro (opened and on) on top of my wife's iBook (closed and sleeping) as if the iBook was a coaster on the table. Within a few seconds my MBP would power off and shut down. Occasionally I'd just throw my closed MBP on her iBook and then try to open it and it wouldn't turn on, or act all funky.

I don't know what was going on. I don't think either needed to be plugged in to cause the effect. I figured it had something to do with EM waves coming out of her iBook or something.
posted by pwb503 at 8:51 AM on October 22, 2011