tearing no matter what i do

[sony818]

Okay so I built my friend this pc specs are below (this not my first build and I pretty much what I’m doing). So I installed windows 7 64bit and it worked fine for a few days. Then he started getting screen tearing in windows watching videos and just doing nothing. In games he could play one Game of csgo before crazy tearing and he would be forced to restart or the screen would go black. So I reinstalled windows 10 64bit all clean. I installed al driver’s gpu chipset.... The gpu drivers would not install because of the windows driver signature enforcement, so I disabled it and installed the drivers and it worked for a few hours than again extreme tearing and it said that the graphics drivers have stopped working or no hdmi detected. Before he had an msi 280x That I think was the main culprit for the tearing so he sent that in and they sent him a r9 390x as a replacement and he is having the same problems I have uninstalled The driver and run the special uninstaller from guru but still having problems any ideas what could be the problem? I tested his computer I ran aida 64 stability test And the temp’s don’t get extremely hot, gpu no hotter than 75 and the cpu around 50The one thing I noticed was that his voltage was a little low like for 12v he was getting 11.9 which is okay for 3.3v he was getting 3.1 or 3.2 and for the 5v he was getting 4.9 so I don’t know what else to do I know I have connected everything correctly it’s not my first build. I’m guessing it’s the power supply it can’t give enough power to the gpu so it just crashes. Thanks for the input this is my first post

cpu-Amd 6300 no overclock
cpu cooler-cooler master hyper 212 evo
mobo-asus m5a97 r2.0
ram-g1snier ddr3 2133
graphics card- msi r9 390x
psu- corsair hx850

 

[sony818]

so i made him take out one of the dimms of ram and that seemed to be the culprit