Solving Macbook Wake from Sleep issue
My girlfriend's Macbook has been suffering from a wake from sleep issue for around 12 months now. It appeared to go away and then last week with an upgrade to Leopard the issue came back even worse than before. The problem: Macbook automatically wakes from sleep with a log entry stating 'USB caused wake event (EHCI)'.
What follows are the steps I've taken to try to eliminate the problem and also what I hope is the permanent solution.
After scouring many articles, blog posts and forum topics I discovered that Apple recommend deleting some plist (preference) files to reset some of the power management functions to their defaults. The system automatically recreates these files on reboot. Another recommended approach was to reset the SMC and PMU on the Macbook. Neither of these approaches appeared to help at all. In case you want to try (it may solve your particular issue) the files to move to your desktop (or delete) are:
/Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist
and
/Library/Preferences/SystemConfiguration/com.apple.AutoWake.plist
Now there is a good chance that the com.apple.AutoWake.plist file is missing from your machine. This is not unusual as according to the developer document about the command pmset:
Files
All changes made through pmset are saved in a persistent preferences file
(per-system, not per-user) at
/Library/Preferences/SystemConfiguration/com.apple.PowerManagement.plist
Scheduled power on/off events are stored separately in
/Library/Preferences/SystemConfiguration/com.apple.AutoWake.plist
pmset modifies the same file that System Preferences Energy Saver modifies.
fies.
This made me realise that the missing AutoWake.plist file would be created if I made a scheduled sleep or wake event, which I did through the System Preferences Energy Saver panel. I then disabled the created wake event and double checked the newly created plist file, ensuring that it was empty of any settings. I then tested the sleep issue I was having and it seems to have cured it.
So what I conclude from my little trial and error experiment is that the system requires the com.apple.AutoWake.plist file to be present otherwise some sleep issues can occur. Strange but so far true.
6 comments
Jump to comment form | comments rssMy PPC mac has issues when it sleeps with a combination of my USB backup drive and USB printer plugged in, waking is a bear at that point, so now before it sleeps I usually disconnect that hub. Hopefully your solution works better, let me know if it did and I will work similar to that!
Wow! Looks like you hit the nail on the head.
I have a macbook that refused to stay asleep for more than 30 secs. After I followed your treatment it is sleeping nicely again.
Hope it stays. Thanks for posting it!
Thanks! This has been so annoying! Between arriving on site with a dead battery to it waking ME from sleep throughout the night I was about ready to put it through a wall.
Man I hope this works for me too! I was woken from several rooms away this morning when I thought a 747 was landing on the house. My G5 had seemingly crashed and the fans where blasting following a 'USB caused wake event (EHC1)'.
My Macbook woke from sleep last night waking me up. As the lid was down it cycled through the wake/sleep cycle two times in succession before going back to sleep. No peripherals were attached, Bluetooth was turned off, no events were scheduled in power adapter scheduling (nor anywhere else that I am aware of) and the AutoWake plist referenced in this article already existed.
So... what could it be? Console only shows the USB event notification. Could be the USBOverdrive control panel that I have recently installed... not sure.
Ditto the Wow and thanks from others above! My MacBook has been acting up lately, despite no 'strings' (USB) attached and Airport & Bluetooth off. Then I created the 'empty' AutoWake plist as per your instructions last night, and so far, so good (knock on wood), my machine is finally sleeping as it should. Heart-felt thanks from a happy camper in Paris!
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