[Win 8.1] Alienware X51 flickers to hdmi screen then reboots randomly?

Recently my X51 has been unexpectedly rebooting randomly especially when playing on a game. It has even done it while browsing through the internet. It started doing this when my computer froze and i couldn't press ctrl+alt+delete or anything like that. So i had to switch the whole power off. Not even the x51's power button on the actual PC would turn it off, so it basically completeley froze. It randomly flickers and reboots quite often even if it's not working that hard. Also when it starts flickering my Alienware TactX Keyboard Lights go off. I have run a scan on windows memory problems,Alienautopsy and mcafee is showing nothing. I have had my X51 for a year now. I have run into a few problems throughout that year though. My graphics card is also up to date.

The fan has been whirring the past month but has stopped since then so i don't think it's that but I have no idea why it flickers back and forth then reboots itself?