I have an Acer Aspire 5750 and if i let my computer sit for 4hrs - 48 hrs, when i open up the laptop lid, my screen is black. The computer is still on, but it won't wake up.
I use Ctrl-Alt-L to lock the computer.
Any help will be appreciated
this computer has the 2nd gen intel core i5 sandybridge integrated graphics. I had the same problem on 12.04 and 12.10