Second mini. I followed the same steps, it all went fine. One difference is that on the second mini, I replaced the ram before turning it on for the first time.

Well, there is nothing for it, just gotta take it in to the Genius Bar. See if they can tell me what is wrong.

I tried both removing all devices (headless) and just the basics. Is there anyway to tell if the power is plugged correctly to the logic board? I mean it looks right, just trying to think of things I could check. The only things I can think of are that the ram is somehow out of alignment in some micro way, (i tried new ram, old ram, wiggling in various directions etc) I didn’t put the power plug back on the logic board correctly or I somehow fried something..

Bricked! Mini will not turn on. Any ideas?

For the avoidance of doubt. I presume I did something wrong. Anyway, put factory ram back in, still doesn’t start.