Alienware Alpha shuts down randomly

If WoW is above 5 graphics or on games like Heroes of the Storm, or anything even slightly demanding, the system just shuts down completely. No blue screen or 'Windows is shutting down', it's just as if you yanked the plug out. The only way to turn the PC back on is to unplug the power brick and to plug it back in. Any help would be appreciated

I have the i7 R2 Alpha and have had it about 4 months now.