Ok, so for the last week or so my pc has recently just been getting a black screen, when this happens, the GPU fan gets really loud, now it happened a few times and i thought nothing off it but its continuing to do so and i believe is happening more often. i have three fans on the case and their is plenty of air flow through the case. All i have been playing is League of legends on one moniter which is not really a demanding game and sometimes a dvd on another monitor, then all of a sudden the screen goes black, the gpu starts to get really loud, but i can still hear sound from the pc for about 1minute after getting the black screen.
CPU - i5 3570
GPU - Sapphire Radeon HD 7870 2GB GDDR5
Mobo - Msi Z77A-GD55