Why does my MacBook keep waking itself up?

May 15, 2008 1:05 PM

My MacBook keeps waking itself up from sleep mode. Sometimes it gets "stuck" in a loop doing this over and over. It happens even with the screen closed. Any idea what's going on?

MacBook 1.83GHz. One of the very first models. It happened on Leopard, so I went back to a fresh install of Tiger. Still happens.

posted by humblepigeon to computers & internet (8 comments total)

Do you have any USB devices plugged into it? I have a mouse that would keep a machine awake, or wake a machine from sleep, whenever it was plugged in; I think it thought the mouse wheel was moving even when it wasn't.
posted by xil at 1:17 PM on May 15

At the risk of asking the obvious, have you tried resetting (aka, "zapping") the PRAM? Because the computer stored many video and keyboard settings in the PRAM (parameter RAM), these setting will sometimes get corrupted, and need to be reset in this manner.

To do this, reboot, and hold down Command (the Apple key) + Option + P + R - four keys simultaneously. The computer will chime, and then reboot again. Do this for three continuous cycles, finally releasing the keys and allowing the computer to boot fully. This may solve the problem, and is usually one of the first troubleshooting steps to try if a simple reboot fails. Another would be to fix file permissions via Disk Utility, but this doesn't sound like a file permission problem, especially since it persisted even after a system downgrade.
posted by mosk at 1:23 PM on May 15

is your firmware fully updated? (apple icon --> software update) AFAIK, the firmware updates requires a special rebooting procedure and doesn't happen automatically.
posted by sharkfu at 1:59 PM on May 15

Probably a failing reed switch. There's a reed switch that gets activated by a magnet when the lid is closed.

Here's a thread that tells where the switch is located and how to activate it with a small magnet:
posted by tomierna at 2:21 PM on May 15

This is a known problem, and one that I suffer from. When it does this, take a quick peek at your Bluetooth status - my bet is that it'll be listed as "not available". Basically, there's some sort of flaw in the logic board which causes the USB connection to get flaky and repeatedly time out and reconnect.

It really, really sucks, as I've tried every rain-dance "fix" on the intertube with no luck. A quick google search for "bluetooth mac not available" will turn up some info, but solutions are not forthcoming as far as I know.
posted by TheNewWazoo at 2:21 PM on May 15

I had the same problem -- when I would close my MacBook for the night, it would repeatedly wake up and go back to sleep, sometimes every minute.

I followed the directions listed on this website and changed my sleep mode to the old-fashioned one. It's not a perfect fix, but my MacBook sleeps through the night now.
posted by pluckemin at 5:33 PM on May 15

I could swear there used to be an option in the network pane of system preferences like "wake on network access"

Now all I can find is "Allow Bluetooth devices to wake this computer" in the Bluetooth pane. Maybe check if that is selected?
posted by ctmf at 5:55 PM on May 15

I had the wakes-itself-incessantly problem with my Macbook. I brought it to an Apple Store, left it overnight, and it was ready for pickup the next day, fixed. Sorry, this was almost two years ago, so I don't recall what they did -- just that some hardware replacement was involved.

If you bought the 3 year Apple Care, you're still covered.
posted by cactus at 6:07 PM on May 15