NEW PC: Black screen and crash on any game.

[great_knight_who_say_ni]

Hello.
I'm having a problem with a new PC build, since my screen goes black when i launch any game.
The thing is, everything is new on my PC, except the PSU.
I needed to get a boost on my pc so i bought:
- Intel Core I5 7400 3ghz
- MSI b250 pc mate motherboard
- 16 Go DDR4 Crucial (2x8go)
- PNY GTX 1070 8 Go XLR8 OC
- SSD 500 go & HDD 1To (7200 rpm)

I have a corsair CX600 since 2012 and i still have my old hdd (5400 rpm). Also have a MSI GTX 960.

My previous pc was on Win 8.1, and when i first installed the hdd on the new set, everything seemed ok, except i forgot i couldn't activate my windows. When i tried install it anyway on the new disk, the problem started, with the new and the old.
When i installed Win10, the same thing occured, with both graphic cards.
Installed on the 7200 rpm hdd, same thing again.
I tried with one or two disks only, still the same problem.
For a while, i went back, tried to fix everything on the 5400 hdd, and i could play for a while, but only on that disk and with my GTX 960.
Then i retried a few weeks later, same thing.
With any game. The screen goes black when the game engine is about to turn on. For exemple, when i launch Skyrim, i get a black screen at the end of the laoding after the main menu, before i get in the game, or a few seconds after. League of legend, after le loading screen when i start a game.
The screen goes black and i doesn't come back. The sound sometimes continues for a while, but when it doesn't stop, i have to restart my computer anyway. Sometimes i hear windows notifying something has reconnected, after the black screen.
After the black screen, the computer never resets itseilf, i always had to do it. I even went for a walk once, upset, and after a long time, still running with a black screen, no sound.
I looked for solutions on internet, found some errors in the event log, like the nvlddmkm error, and some more. The thing is i tried with the 2 HDD and the SSD, with both graphic cards, tested the drives with Crystal Disk Info, reinstalled win10, used DDU to clean and reinstall, tried an old driver, updated everything that needed to or just could be.
I didn't check the memory, though, and didn't flash the bios.

I have no way to test the mb, the proc or the psu alone, so i'm afraid there is something wrong with these. But with the logs, i don't know what is what and what to do anymore. If i had any AMD card, i would see if it's related to NVIDIA is some way, or if it's material.... i guess...

So i ask for help.

 

[great_knight_who_say_ni]

I decided to buy a new PSU and now it works fine.