PC keeps blacking out league of legends client, and blizzard; Mouse lags after left pc on last night to download

[rathaloss]

I built my friend a PC not even a week ago; It was working fine for me zero problems.
But the same day he got it he was having problems with his league of legends client randomly blacking out and battledotnet then coming back.
He left his PC on last night to download a game.
He says when he got on it in the morning the mouse was lagging.

Could it be the graphics card?
All i'm finding for psu cords is PCI? But his had PCI and one other at the end that I think started with an S.
I'm wondering if it matters which one I plugged into the GPU.

His build:
EVGA GeForce GTX 1050 Ti FTW

Seagate 2TB BarraCuda SATA 6Gb/s 64MB Cache 3.5-Inch Internal Hard Drive

Corsair Vengeance Pro Series 16GB (2 x 8GB) DDR3

AMD FD8350FRHKBOX FX-8350 FX-Series 8-Core Black Edition Processor

Windows 7 Professional SP1 64bit

Cooler Master Hyper 212 EVO RR-212E-20PK-R2 CPU Cooler with 120mm PWM Fan

Phanteks Enthoo Pro Full Tower Chassis with Window Cases PH-ES614P_BK

MSI 970 GAMING DDR3 2133 ATX AMD Motherboard

Corsair RMx Series, RM1000x, 1000W, Fully Modular Power Supply, 80+ Gold Certified

Asus 24x DVD-RW Serial-ATA Internal OEM Optical Drive DRW-24B1ST (Black)

PLEASE HELP THIS IS CONFUSING!

 

[rathaloss]

update: I've tried other gpu's witht he same problem... I think im gonna take back the cpu and mobo; To see if that helps

 

[rathaloss]

Didn't help