Pc (suddenly) crash on boot up

[Stilatos]

Hello guys, i have a problem and i would like to ask your help coz i didnt find any information that have to do with it.

My PC
CPU : I5-3570
GPU : GTX 970
MOBO : Z77A-G45
PSU : COOLERMASTER RS-600-ACAB-D3 600W
RAM : C.VENG 8G
OS : SAMSUNG 850 EVO

Now to the point. i build this pc 4 yaers ago and until yesterday i had no problems at all (1 year ago i pass from asus gtx 760 to gtx 970).
like always i was playing my favorite game and everything was perfect. arround 3 on the morning i was tired and i switch of the pc.
This morning i switch it on and here is the problem, i hear the pc working, all lights was on, the fan of the cpu (liquid cooling) was working BUT screen was black and after 5 sec pc switched off alone, 5-10 sec later switched on alone and again black screen even if all working and again after 5sec it switched off , 5-10 later switched on again ...... this happed 4 times, at the end i i took off the cable coz i dint know how to stop it. i retry to switch it on again but had the same problem.
I was thinking maybe is the PSU but not sure. any i idea ??

thank's in advance and sorry for my bad english.

 

[SgtScream]

Is your motherboard's bios version on 2.C?

 

[Stilatos]

I dont think is the bios coz like i said i it was working perfectly, btw bios was updated june 2016 to the last version 2.C.

Problem solved : was the motherbord

 

[jwcrellin]

Unseated ram or bad ram will do that too. Pull out all the dims and just install 1 in the farthest away slot from cpu. Make sure its fully seated and the clips snap up.

 

[Stilatos]

Unseated ram or bad ram will do that too. Pull out all the dims and just install 1 in the farthest away slot from cpu. Make sure its fully seated and the clips snap up.

I try everything mate, but didnt work. At the end i put Cpu and ram to an other motherboard and was working perfectly.
Thanks for your time