I recently bought an 850 G2 and when I built my computer, it keeps turning on and off. I press the power button, the PSU clicks on, 10 seconds pass, it clicks off.

I hve removed my audio driver, graphics cards, unplugged all but my SSD, reseated the RAM, and checked all the power connections and the problem still persists. This is the first time booting up the computer so the OS has not been setup.

Any suggestions?

you get 24pin PSU tester within the PSU package.
in the manual you can read how to use it.
just test the PSU with this tester and if you get the same issue your PSU is probably faulty.
you should contact EVGA and RMA your product.