PSU dosnt want to work with my sustem

I recently bought a new PSU to replace my old one in my system because im upgrading my gpu but wheni put it in it didn't work my first thought was that the PSU is Brocken but it wasn't I tried it on a different system worked fine I got my old psu and put it in the system and it worked leaving me very confused if anyone could help please

Submitted November 30, 2017 at 01:50PM by KiiZ1Y http://ift.tt/2ipDSSR