I have a thermaltake 850 watt cant get the exact model at the moment not near the comp. But could a PSU cause a lockup like that? Every time I have had PSU prob it has either just shutdown the system or would act funny booting. All 5 fans plus my CPU fan run fine all LEDs pop on as well (including keyboard and mice lights). I have an extra PSU and I guess I will try it next time I get a chance.