I will check this today no doubt. But I think it was plugged in right. Tried a couple of times to unplug.when using SM PSU, make sure plug firmly atx and eps12v...
I had one stupid mistake at one time due on excitement having SM case at the first time,
eps12V was connected, but did not have good connector contact.
Can be switched off and on via power button and just give a blank screen /
one last option, try on another motherboard with SM PSU...
I also got my fingers on 2 other PSU's I can test with. So my fingers are crossed all day