Aurora R4 shut down after 15mins

Hey can anyone help me out. My Aurora R4 fires up great. I log into windows and start doing whatever. After 15mins my computer just shuts down. No re-start just turns off completely. I cleaned it out, removed my power supply and checked the green light. Seems that everything is working but then it shuts off. My fans i noticed run loud but I have turned down my temp. Any suggestions would be great.