Have you turned on fast boot or made other recent BIOS changes? I found instructions to enter BIOS when the BIOS won't "open"
Power off the NUC. WHILE OFF, push / hold power for 3 seconds. Then, try F3 but it must be pushed within 4 sec of releasing the power key. If you get to BIOS,try resetting to factory default which I think is F9, then F10 to save and exit / reboot.
Hope that works.
No, I saw this occur with an earlier BIOS as well, so you just haven't hit it yet.
The most common reason for an unsuccessful POST occurring is that the BIOS cannot get the memory configured to operate properly. In this case, I think that this is exactly what is occurring, but it has nothing to do with the memory itself. I believe that something is going wrong during the shutdown/suspend that results in (I am guessing) the memory buses locking up and the BIOS's attempts to clear this locked state (by programming the memory controllers) are all failing. This is purely conjecture on my part, but it is something that a BIOS engineer can test for in his debugging...