Seamingly random flashing screen (off and on) // PLEASE HELP!!

//the back story
Since I got my XPS 17 it has had a problem. It used to always go to sleep seamingly at random.  I called Dell Support and they sent out a technition to look at it. It was then fixed for a couple of months, but the problem started again. I ensured all the drivers were up to date, and that there were no settings that would enable the computer to sleep. Once again a technition came out. The problem came back the next day. Dell sent out one more technition a month later and the problem went away for a week.

//the current problem
My laptop has gone from going to sleep randomly and consecutively to the screen turning off and on. It does this seamingly at random. When the screen turns off and I touch the mouse pad it will turn back on.  If I have an external monitor plugged in when the screen turns off, the external monitor becomes the primary monitor until I touch the mouse pad/mouse pad buttons. The screen doesn't just turn off once and then go back to normal, it will usually flicker quiet a lot and turn off and on straight after each other. 

My warranty recently ran out, so dell will no longer help me. I was wondering if anyone else had any ideas?

//further information
Sometimes the video drivers will stop working altogether when this flashing starts happening.