Pc infinte on and off

[rahmanakbarmian]

hey guys i made my first pc yesterday and whenever i turn in on stays on for 8 secs and turns off and then on and it just keeps in going i took everythingout and testes it with my motherboard ram cpu and my cooler and it still happens i might add maybe i didnt apply the thermal paste properly if that has to do with anything

 

[helpstar]

which components did you build together?

Power connectors all plugged in especially the 8Pin ATX12V plug and the graphics card PCIe power