Black screen after/ at startup- New pc

[Ephesius]

Im having the worst nightmare ever. I purchased a new gaming rig. But after windows loads im having black screens randomly at 2-5 mins without doing anything. Screen goes black- gpu fans keeps spinning- processes continues such as music. My specs;

Intel i5 4670k
Asus Z97-AR
Sapphire R9-290 Tri-x oc
Gskill Ripjaws 2x4gb 1600 mhz cl9
WD Carviar Blue 7200 rpm
Psu : Xigmatek Vector S 750w 80+ silver modular

I went back to the place i bought, they changed my GPU with gtx 970 with fresh windows and drivers - still the same issue.
They changed my memories- still same
Changed mobo- still same.

What the hell is going on with my pc? Psu is tested and its working as it should and it is enough for my rig.

Anyone has a thought about what might be the reason for this?

 

[ZeusGamer]

What kind of PSU do you have?

 

[Ephesius]

Xigmatek Vector S 750w 80+ silver

 

[MarcusGJ]

well if the pc shop you bought the system from has changed everything but the psu, and the problem persists, I would go with the assumption its a bad psu, problems may not occure until its under a heavy load when in games etc.. try swapping it out, running with a different psu to check if the problem goes away but if the music continues to play maybe a dodgy monitor mate

 

[Ephesius]

Well i solved the problem by returning the card and getting a Asus Gtx970 Strix instead. Everything is fine