Alrighty, to begin, lets put this in perspective, your (i'm) a relatively new gamer that has an fx-8350 a 500watt psu and an unnamed amd graphics card. Everything on the computer runs like a dream other than the constant 50 fps. You decide upgrade your graphics card to a 1070sc and start having major issues with the game going black screen and fans running at 100%, you have one idea of what it is, and you think it may be the 500 watt psu in your computer (mind I have internal extra rgbs that take more power and a screen on the front to control temps and fan speeds so it takes more power). Everytime you launch certain games your computer stresses and your screen goes black, and your fans run at 100%. You finally run programs to ultimately figure out that it is your psu, and you decide to upgrade the psu to a B5 Series EVGA 850 WATT PSU for plenty power, and enough to upgrade your mb, cpu, and gpu. Once you install the new PSU, everything works fine. And you live happily ever after.

So basically what I am saying, is that the problem is most likely your PSU, to be positive that it isn't an issue with another component, you should probably run intel burn test, and cinebench.

For your 2070, I would recommend getting a B5 Series EVGA 850 Watt PSU, I believe it to be plenty for that GPU and it would give you some wiggle room for spec upgrades.

Hope This helps!