The other morning, as is my morning routine, I plugged in my laptop (Alienware Area 51m R2) and pushed the Alien head power button to turn on my laptop to start my day.  I stepped away for a moment and when I returned noticed that the computer wasn't on.  I thought that perhaps when I went to hit the power button I maybe hit to the side of the button and it didn't turn on.  However, I did notice when I had plugged in the two power blocks that i had actually plugged them in the opposite ports.  The cord with the blue light was plugged into the port on the left (as I am sitting in front of it) and the other was plugged into the port on the right.  So I unplugged them and put them in the correct spots.  The alien head was on.  So I hit the power button to start up my laptop.  The Alienware logo came on and there was a spinning circle below that.  I looked away and when I looked back the screen was blank.  I waited a moment and hit some of the keys and nothing happened.  It was if the computer shut off and wouldn't turn back on.  I unplugged the power supplies and anything else plugged into the laptop.  Next held down the power button for between 30 seconds to a minute to drain residual power.  I put the power supplies back and tried to turn it back on.  Nothing.  The alien head didn't even light up,  I even unplugged the power cords and tried to turn it on.  No go.  

I have had this computer for just over 5 years and it is no longer under hardware warranty.  Any suggestions on how I should start looking at what the problem may be ?