Works 100% i test it many Times. I think u can use this How to with any NUC Model. I do this with my 6i5syk
http://www.intel.com/content/www/us/en/support/boards-and-kits/000005532.html Intel® NUC BIOS Recovery Update Instructions
This 'solution' was thrown at me by Intel as well, a few weeks back.
Didn't work, or better said, my NUC was in a state that the BIOS couldn't be recovered so I couldn't even try the fix.
I didnt have video signal, the disk didn't spin up, the USB ports were dead.
I did have a solid blue front led, and I saw the Network adapter leds blinking, oh and there was a loud whirring sound coming from the fan.
The strange thing is that the NUC had committed suicide while I was away for a coupe of hours. Had to RMA it.
Writing this post from my 3rd NUC6i5SYH.