Dell 8900, Gaming Computer, Dell Alienware Aurora

Two months ago bought a Dell 8900 from Best Buy. After 20 days, it would not start, same with the next 8900 replacement... only fewer days. The first gameware as a replacement did not start at all. The Alienware Aurora worked beautifully for 3 days and then would not start. In the 8900's,,, got the blinking amber lights on the start button. Tech is coming to replace motherboard. What the heck is happening? Could it be the monitor... or the external hard drive or what? Come on Dell,,, what's up? I have a Dell XP Laptop as a back up using the same external hard ddrive.