My personal laptop, is only several months old, but has exhibited this behavior about a month in. I set the power settings on it to do nothing when I close the lid when plugged in. I use the laptop to stream onto my tv via a HDMI cable. I usually leave it connected to the tv and in the evening I power up my tv and use the mouse to navigate around and stream some shows. The problem arises when I go to use my laptop by itself. I disconnect the HDMI and then my power cord take laptop over to the couch or where ever lift the lid and its black. I hit various keys to wake it up and sometimes I hear it beep so it must be getting some sort of input but screen will not come back on. Only option I have is to hold down the power button and hard reboot the damn thing, which I'm sure is not doing the hard drive any favours.
Just putting this out there, maybe someone else has had this issue and found a solution.