odd PSU issue

[jojo69]

OK guys, I got a weird one here

I have on the bench an Antec Neo HE550.

If I ground the green wire it comes up fine, voltages check out, runs a bunch of fans no problem, but 2 different motherboards the power button will not start it.

Then it gets even stranger. So I'm sitting here typing this, like a full minute after pushing the power button, and the system beeps behind me and POSTs...

 

[Jorona]

Not enough load is my bet. Some PSUs will do REALLY odd things with a really light load.