Sleepless MacBooks

My MacBook, like many people's, is an insomniac. If you put it to sleep, from the menu or by closing the shell, it wakes up again, in a few seconds. This default behavior will empty your batteries and overheat your machine in its case.

Now, many things can cause this: mostly hardware interrupt handlers containing instructions to wake up. I first Googled this problem with the phrase: macbook does not stay asleep, but the Apple discussion board is completely disorganized. At the top of the page, it announces "1 solution" but doesn't give you a hint as to where it may be, in pages of discussion! I found it eventually, but I thought it would be helpful just to say:

... turn off Bluetooth.

It's in Systems Preferences under Hardware -> Bluetooth. Your computer will then get the rest it needs, without pills.

Addendum:

If the Bluetooth hardware is failing, the Bluetooth symbol has a little squiggle through it.


This makes the system write a hardware error to the system log (/var/log/system.log) every second. This wakes your Macbook consistently.

In this case, without repairing the hardware, you'll need to put your machine into hibernation, instead of sleep. There's a useful widget for this, called Deep Sleep.

Your Bluetooth hardware may start working again. Anytime you see the grayed out Bluetooth symbol in the upper right, without a squiggle, you'll be able to sleep normally ... if you turn Bluetooth off.