Power turning on and off in my new build

[BillyPoirier]

This is my first time building a PC and after assembling it, I turned it on and the CPU, GPU and one case fan turns on for about 10-15 seconds until they power off again for 3 seconds and then the cycle repeats.  

These are the steps I've taken to troubleshoot:

-tried re plugging it in to power

-changing the outlet

-took it out to see if the PSU fan was running (it was)

-I ended up returning my psu and getting a new one but had the same problem.

I tried googling the issue but couldn't find any other problems matching mine.

parts list:  https://pcpartpicker.com/list/srx6LP

[jaslion]

Have you tried your computer outside of the case? As in on the motherboard box?

 

Also ram in correct slots?

All power cables correctly connected?

 

Maybe post some pictures?

[Zusafek]

11 minutes ago, BillyPoirier said:

This is my first time building a PC and after assembling it, I turned it on and the CPU, GPU and one case fan turns on for about 10-15 seconds until they power off again for 3 seconds and then the cycle repeats.  

These are the steps I've taken to troubleshoot:

-tried re plugging it in to power

-changing the outlet

-took it out to see if the PSU fan was running (it was)

-I ended up returning my psu and getting a new one but had the same problem.

I tried googling the issue but couldn't find any other problems matching mine.

parts list:  https://pcpartpicker.com/list/srx6LP

Sounds like a bios update is needed.  B450 with ryzen 3600.