Question on PSU compatibility. EVGA Supernova 650 GS.

[Rookie_MIB]

Got an odd problem, wondering if anyone else has it, or might have some ideas.

My rig is as follows:
Asus P7F7-E WS motherboard, Xeon X3470, 4 x 4GB RAM, 3 x 4TB Seagate ES drives, 2 x Samsung 830 SSD, 2 x GTX960 (SLI), 1 x Intel PCIe dual lan card, 1 x generic PCIe SATA adapter.

Previous PSU crapped out on me (Strider Gold 750w unit), popped in a cheap CM 625 PSU to run it while I found a new supplies. Picked up a new (open box) EVGA Supernova GS 650.

Put the PSU in, power light on mobo comes on, pushing the power button does... nothing. No fans, no beep, no post. Put the PSU tester on, no dice, nothing powers up. Barebones connect the CM 625, the rig powers right up.

Put the EVGA on a basic rig (Gigabyte ITX, Pentium G3220 and two drives (SSD/HDD)), the unit powers right up.

Any thoughts on what might be going on?

 

[Dunlop0078]

Well your psu tester is likely broken or you are not using it right. If it powered up the basic computer it works. I would assume something wasn't plugged in all the way or there is a short or something not allowing it to power on.

 

[Rookie_MIB]

The PSU tester (black piece which clips on to the 24pin connector) does work - it forced a power-up of the CM 625 PSU just fine. Even only inserted partially - it turned right on. Connecting what would nominally be the 'green' wire on a colored wire loom for the EVGA unit (as the entire cable set is black), the PSU does NOT power on. (BTW eco mode is off).

Tis a puzzler.

 

[Rookie_MIB]

Did some testing and I'm pretty sure that the PSU is bad. Dammit. Pin to green wire (16) is supposed to put out 5v with the unit plugged in and nothing on (grounding causes power on), it's putting out 1.95-2.0V. Likewise, purple wire (9) is supposed to put out 5.0v (5vsb) whether the unit is on or off, it's putting out 3.8v.

Sooooo... crap.