Question PC turns off while heavy gaming or when running Heaven benchmark ?

Mar 23, 2023
I got a 3080 that was working fonr, just for gaming, for over 8months now, but since 1 week ago my PC just started to turn off after 30 mins of playing games like Jedi fallen order, So I decide to run cinebench, iwhc went fine and then heaven benchmark, Altho my GPU only went op to 73C in core and 86 C hotspot, the memory ram went up top 94C, I dont think that is the issues tho since there was no trottle during the test the card remained at 1860-1915 hz clock speed. But it just suddlenly just turns off. Could it be the motherboard or my PSU?. I got a ASUS Z270 and a bequiet 850W gold PSU.