Is there some trick to getting these Pico PSUs to power on the motherboard that I'm just not seeing?  I have plugged the Pico PSU into the 24 pin connector on the mobo.  Plugged the EPS pigtail into the CPU EPS connector on the mobo.  Then plugged the 6 pin cable and barrel adapters together and plugged that into my server PSU's breakout board.  I get a blue light on the Pico PSU so it appears to be getting power properly... but when I hit the power button on my rig, nothing happens.  If I unplug the barrel adapter and plug it back in, I see the CPU fan spin for a second.  This is the same behavior you will see if you are using a regular ATX PSU and you pull and re-plug the power cable on it.  So it seems like everything should be connected properly... but it just won't power on.  If I remove the Pico PSU, and plug in a spare ATX PSU to the same 24 pin/EPS connectors, everything powers up just fine.  So, I know there is nothing else configured incorrectly.  My server PSU powers my GPUS just fine, so I know the server PSU  and breakout board works fine.