strange PSU problem

hi guys and gals,
so before i changed my mobo (was a p6t se) i had my Lepa G1000w working fine. I upgraded my mobo to the current one and the PSU just clicks, fans do 1/4 turn and nothing. It is a modular psu. I put in my cheap xeon 850w and the system works fine. Ive sent the psu back to enermax 3 times and they just keep sending me another....now all 3 cant be doa. i even sent the cables but im not sure if they changed them, and when i called i may as well let my dog make the call because they could barely understand English (shock).

So im stumped and about to give up and waste $100+. any help or advice would be appreciated. ive checked to see if its compatible, it says it is. there cant be a bad earth or the cheap one which is non modular would not work. i also did the pin check and it works...im stumped

Bad cable, or you're mis-installing one somehow. Doubt they were ever checked.

clear your bios and inspect the cabling. in particular the 12v CPU cable.

sounds like a misfire due to cpu power issue if there's a quick power self test and no beep code.

or a bad ground leak somehow when the psu is installed.

(last time it happened to me I was stumped for best part of a day until I realised the case manufacturer had wired the case power on reversed)

Make sure you're using the correct cables in the correct places. Using a pcie cable for cpu power (or the other way around) will give you a direct short from 12v to ground. That's bad.