HP z400 Workstation not turning on after new PSU.

[Mason_1]

I am trying to upgrade the workstation into an entry level gaming computer. I am trying to put a EVGA 500watt PSU in for a new graphics card. With the new power supply the computer turns on for a spit second then shuts off. As soon as I reconnect the old HP PSU it fires right up. I also noticed on the motherboard connector the new PSU has one less pin in the housing, compared to the old one.. I am wondering what needs to be done in order to get this computer working.

 

[GhislainG]

Did you modify the 24-pin connector? https://community.spiceworks.com/topic/200275-problem-with-hp-z400-and-antec-psu-750-w https://plus.google.com/photos/111388964237560787781/albums/5362166283613539361?authkey=CPmyw--dmNrUbw http://www.tonymacx86.com/retail-cases/178172-full-atx-hp-z400-workstation-case-psu-cpu-cooler.html

The missing pin is not used in newer systems.