osx lion never stays in sleep mode

Question

Since I updated to OSX Lion I got a strange issue. I am used to never shut down my Mac, I simply put it in hibernate / sleep mode.

But since the update to Lion the mac just starts up at random times. Day and Night I can hear the CD-Drive sound when it wakes up. The screen does not even go on, it stays black but the as soon as you hit any key the monitor just turns on.

This is really annoying as it sometimes wakes you up at night when you MAC is booting up. I could not find a similar issue reported yet.

Thanks Sebastian

Answer 1

Launch the Terminal and type the following at the command line:

syslog |grep -i "Wake reason"

• OHC: stands for Open Host Controller, is usually USB or Firewire. If you see OHC1 or OHC2 it is almost certainly an external USB keyboard or mouse that has woken up the machine.
• EHC: standing for Enhanced Host Controller, is another USB interface, but can also be wireless devices and bluetooth since they are also on the USB bus of a Mac.
• USB: a USB device woke the machine up
• LID0: this is literally the lid of your MacBook or MacBook Pro, when you open the lid the machine wakes up from sleep.
• PWRB: PWRB stands for Power Button, which is the physical power button on your Mac
• RTC: Real Time Clock Alarm, is generally from wake-on-demand services like when you schedule sleep and wake on a Mac via the Energy Saver control panel. It can also be from launchd setting, user applications, backups, and other scheduled events.

Hope this fixes your problem.

Answer 2

Given the RTC (Alarm) wake reason, ensure Wake for network activity is turned off. See the last comment in the thread at https://discussions.apple.com/thread/3247367?start=0&tstart=0

Also ensure you have not scheduled wake. See http://osxdaily.com/2010/07/17/why-mac-wakes-from-sleep/