Computer won't boot ... screen goes black and computer makes a whining noise

My Alienware x51 is 2 yrs old. It has been working great. All of a sudden it stopped booting. It tries to boot then the screen goes black and makes a whining noise. The computer is still on but display is black.

We took it to a repair shop and they said there was a conflict with windows and Alienware trying to update the same hardware.They said they set it so Alienware would update instead of windows to resolve the conflict.

We brought the computer home, hooked it up and it was still having the same issues. We took it back to the shop with our monitor and the computer works fine with no problems at the shop.

So, we bring it home again and it still does not work. We tried several different outlets in the house and took it to my sisters house next door and it still has the same issues. Even the repair guy is stumped. Anyone have a clue to what the heck is going on?