XPS15 laptop randomly hibernates

I have a 4 or 5 year old XPS15 laptop that I purchased new running Windows 7.  Computer has ran great until a couple of weeks ago.  It has now started to randomly go into hibernation.  This will happen anytime and I can't find a pattern.  When the computer does come back on, I don't lose anything even if I was in the middle of typing an email.  All hibernation setting in Control Panel are set to "never".  Below are things that I have seen and tried.

-50% of the time the computer will hibernate then un-hibernate itself within a few seconds

-10% of the time the computer will hibernate and will come back on when pressing the power button as you would normally

-40% of the time the computer will hibernate and not come back on for 2-3 minutes.  I will close the cover and unplug it and that seems to wake it up, but not really sure if it is coincidence.

-I use the laptop screen and a separate monitor.  Sometimes when it comes back on the laptop screen is black but my other monitor works.  Sometimes I have the opposite happen.  Eventually, both screens will work after a random hibernation

-This random hibernation also occurs when I am in the BIOS screen using the F2 key at boot up

-I have updated all my drivers and BIOS to the latest versions with no effect

-The random hibernation has no pattern that I can find.  Does it no matter what software is running.

Please help!