boot problems Newly built computer will not boot up

[SHUG]

I'm not sure if this is the right section to post this but I am having a lot of trouble booting up my new computer. essentially what happens is I turn it on, the LEDs and fans spin, the hard drive boots up, then after about 15 seconds it will turn off and restart again. I don't think it is a short because i have reseated the mobo among other components and i can keep the everything inside the PC running if I press the case's refresh button every few seconds. I have only tried booting it with a HDMI cable because i can't find a VGA so could this be the problem? any help would be greatly appreciated.

 

Thanks, Hugo

 

P.S. I have tried a few troubleshooting guides but nothing seems to have worked.

[Tylerebowers]

reseated the ram yet maybe you have a bad stick

[SHUG]

1 minute ago, Tyleredbowers said:

reseated the ram yet maybe you have a bad stick

I've tried that but no luck there

[Tylerebowers]

1 minute ago, SHUG said:

I've tried that but no luck there

try one stick at a time

[Tylerebowers]

also check the cmos battery

 

[SHUG]

i've tried the CMOS and I just tried the RAM without luck.

 

Also i was just looking at the PSU fan and it seems to turn off 5 seconds before the rest of the PC

 

[Silencer]

2 minutes ago, SHUG said:

i've tried the CMOS and I just tried the RAM without luck.

 

Also i was just looking at the PSU fan and it seems to turn off 5 seconds before the rest of the PC

 

Okay, what's the psu model?

[SHUG]

6 minutes ago, Silencer said:

Okay, what's the psu model?

Corsair CS650M

[SHUG]

I just found a VGA cable and plugged it in. all good now except that i feel like a tard