PC fans run wild and screen goes black issue

I had just bought this PC and everything has been working great. However, randomly my PC fans start spinning really fast and my screen goes black. My PC is still on because last time it happened, I could still hear my youtube playing. Could this be a GPU issue? I've reseated my GPU and RAM sticks and am really hoping it's not a GPU issue? I don't have overheating issues because I've played heavy games on ultra settings and the CPU and GPU temperatures were in the mid 40's to low 50's °C at most.