I have built a good number of these, but I have one brand new board I can't get to even boot to the setup screen.
When I start it up the PSU stutters twice then on the third go it runs. CPU fan turns, I hear the HD click, but no lights on internet connection, not video.
I had something like this happening with one H97 anniversary board.
I got a suggestion to look at the CPU bed and see if any of the tiny connectors are out of place (bent on one direction or another). sometimes you can see this as an imperfection even with a naked eye first.
I had to look under the strong magnifying glass-and there were multiple connectors (looking like tiny needles) out of alignment.
I used the sharp forceps and/or a needle to nudge them back in order, but it was very precise work under the strong magnifying glass.
I had one in the lamp, so it helped with illumination.
You can easily overdo it. In the end it worked and it posted, etc.
EDIT: I see that you are saying that you examined the pins...maybe take another look at bed pins, especially on the periphery, where it is difficult to see...try first with a naked eye, then with a mag glass. At first i only adjusted pins in the middle (did not see bent pins on periphery), then after adjusting all it posted. Could be something else, though.