My Macbook Pro goes to sleep when I connect the magsafe adapter.

Question

Hi, if I am using my MBP on battery and then 1) close the lid to put it to sleep, 2) later connect it to the magsafe and then 3) try to wake it up (in that order only, and more frequently if in the login screen), it powers up for a second then goes back to sleep. Not always but frequently. It takes about 10 seconds to power down, and then once asleep, it takes about 5 seconds before it will wake up again. After that, everything is fine. My only workaround seems to be to wake the computer first, wait about 10 seconds and then connect the magsafe. Has anyone else experienced this? I never noticed this before I upgraded to Mountain Lion.

Answer 1

This very well could be the same issue as below.  Please read the full copy of the post and see if the behavior matches.  What's happeing is that if you have this update installed, whenever you plug or unplug the power adapter to the laptop, the system will wake from sleep and then go back to sleep if the lid is closed.  What you're doing is plugging it in which causes it to wake up, then when you finally open it a couple of seconds later, you're catching it as it's going back to sleep and once it does that it then sees that you opened it and wakes back up again.  Either plug it in and wait for that wake/sleep and then open it or open it and then plug it in.
Post about the problem in detail:
This is a problem with all 2012 MacBook Pros that have applied the update DL1609 via Software Update.  This update is called MacBook Air and MacBook Pro Update 2.0.  The only fix that exists for this is to reinstall OSX and just not install this update when it shows in the available updates list in the AppStore.  Just hide it until this issue is fixed by Apple.
If your OSX 10.8.2 version is anything after version (12C60) then you will have this problem.  The problem is as follows.  With the system asleep with clamshell closed, plugging and unplugging the power cable causes the system to wake up and go back to sleep.  Additionally, leaving the system plugged into power for over 4 hours will cause the system to go into hibernation, but only when plugged in.  If it's not connected to AC power while sleeping for that long, it will not enter hibernation.
Please call Apple and complain about this problem.  I have been working with them for over a month and a half trying to get them to fix this and it's a major hand-holding process because they didn't initially understand the issue.  Add to that the fact that they insisted that this problem doesn't exist and it just made it that much harder to get them to see the issue.
You need to call them AppleCare and let them know you're having this problem.  Along with that, email the rep you're working with links to every Apple Support Forum thread you can find on this.  Trust me, there are several with this same exact problem.