Question What’s wrong with my psu ?

Mar 1, 2019
6
1
10
So recently I asked a question on a power supply. Following that I bought a new psu and I tried hooking it up but it didn’t turn on. At All. So I checked everything and made sure everything was in properly. And it was. So I took It out. And out in my old psu to make sure I didn’t damage anything. And sure enough. It turned on. So I put the new psu in again. In case I missed something but it didn’t turn on. I made sure the right amount of power could flow through my adapter into the psu. And that I had the right amount of wattage to power the system but everything added up. And I really don’t know what to do anymore.

My components are a ryzen 5 1600
An asrock ab350 pro 4
My graphics card is a rx590 fatboy
I’ve two sticks of Corsair LPX 4gb ram
And the power supply is a seasonic m12II 620W bronze evil edition

I’ve spent a long time trying to figure out what’s wrong but I can’t find anything so this is really my last hope