PS3 shuts off randomly after minutes

So i was playing portal 2 and for some reason after about 3 minutes while playing the game the ps3 flashes the yellow light real quick and shuts off, i dont think it’s because of overheating because after touching the system it’s barely warm, is there any other correlation?

Couple things to know -it’s jailbroken -it’s a fat model -it’s Japanese

Thanks!