I have also a problem with my NUC. It was on BIOS 40 and I thought I will upgrade to 47. I upgraded using the F7 process and the update went well.
However, after reboot I went to BIOS and after about 5 seconds the whole screen went corrupt. like lots of colors everywhere. I shut down the NUC and started it again but no picture displayed at all, the blue light comes on for about 2 seconds, then the NUC powers down for about 3 seconds and then turns back on and stays on. No picture displayed.
Resetting CMOS, trying emergency BIOS recovery procedure, none are working.
I contacted RA team, I chatted to someone who ended up issuing new replacement and told me I will receive instructions on my email what to do next. Its been now 18 hours since the chat and no email so far.
Not impressed with Intel service so far. Also everytime I try to start new chat to get an update:
Sorry, all of our Chat Agents are currently unavailable. Please try again later or go to our support sites for further contact information
seriously Intel, how can you not have enough ppl working? Really bad customer service.