[scarecrow420]

Not specifically NUC related but from a general computing perspective: In my desktop PC I was trying to get a 16GB matched set of 4 G-Skill RAM sticks working and it would not post. I could use any combination of any 2 sticks of the 4 in any motherboard slots and it was fine, but as soon as I added a 3rd or 4th stick it would not post. I finally got it to work by going into BIOS and manually configuring the RAM voltage, timings etc as per the RAM specs and the machine started up with all 4 sticks. Essentially the motherboard auto SPD setting was somehow not working (perhaps it was setting the voltage on the low side as the RAM specs said 1.5 - 1.6v and when I manually configured everything I set it at 1.55v).

So you could try getting into BIOS with 1 stick of RAM installed, then manually set the RAM speed timings and voltage according to your RAM specs and see if anything changes. If that doesn't work you could even try a minor voltage increase over stock voltage (be careful/research safe limit first etc) just to see if that changed anything. If still no joy then look to take the NUC and/or RAM back to the shop you purchased it from and see if they can either try alternative RAM or try that RAM in an alternative NUC