Screen turns off at lid opening
There is a similar discussion on discussions.apple.com from which I picked the hint to run
pmset -g assertions
to list a summary of power assertions. Assertions may prevent system sleep or display sleep.
In my case I had a print job in queue that was preventing sleep.
I stumbled onto this link when trying to find out why my 15" MBP (late 2011) macbook pro with Lion (10.7.3) would not keep the display on after opening the lid and plugged in.
Steps to reproduce:
- Plug in your laptop.
- Close the lid.
- Open the lid.
- Type your password.
Expected result:
The laptop wakes, the display shows the login screen and remains on.
Actual result:
The laptop wakes (the keyboard is lit), the display shows the login screen for approximately 3 seconds and then goes dark.
Workaround:
Unplug the laptop, and successfully login then plug the laptop back in.
Fix:
As another poster stated, it's the network attempting to access resources which shouldn't be available when the lid is closed then when waking the laptop it is technically already awake. I did not have internet sharing enabled, however, the only difference between adapter and battery options in my settings was "Wake for Network Access".
- Open your System Preferences.
- Click Energy Saver from the Hardware section.
- Click Power Adapter.
- Un-check the box for "Wake for Network Access".
This resolution assumes that Internet Sharing is not enabled in System Preferences -> Internet & Wireless -> Sharing