[Jacques]

I suspect your CPU isn't properly seated on the riser cards. I've had this tons of times when I've taken my processor module out to mod it. Make sure you hold the bottom base of the system board tray under the risers, then push down gently on the heatsink to ensure the CPU contacts with the risers. Force boot jumper and it should fire up.

You should ideally look for a fan that provides around 3 mmH2O or 30Pa static pressure, 2 is a bit on the low side. The flow rate of the Noctua is fine though.