Venue is frozen

Got it two weeks ago. Set it up but haven't used it. Tonight I turned it on and it said an update was due  I chose to update and restart 

7 min later it still said restarting. I shut it and turned it on. Now updating and it hit 30%. Then it restarted. Well, almost. Screen is backlit but gray. Can't turn it off. Won't go to sleep. It's just frozen on a dead screen. 

How do I bring it back to life?