Happened again.  Called tech support and demanded my $ back after the tech could not fix after another hour of noodling around with drivers etc.  Wants to have the screen replaced when it is not hte screen and I have had trouble with all three.  the supervisor, Arijat told me I had to call customer care tomorrow to see if they will issue a complete refund.  I am not confident that will happen but its clear that Dell cannot figure out how to eliminate this recurrent problem nor fix it once it occurs.