This message was posted by Intel Corporation on behalf of
I just wanted to let you know that in regard to your issue, pretty much you tried everything that we recommend at this point.
Some other troubleshoots steps to try will be to reset the BIOS to defaults, or to do a BIOS update to another BIOS version besides the ones you already try.
Also, even though the memory RAM seems to be fine, you can try for testing purposes to use the NUC with just one memory stick, and the try the other stick, just to rule out a possible RAM problem.
Another option will be to test it with a different SSD, if you have the option of course.
Also, if the option is available, you can try to test the NUC with a different power adapter.
In regard to the TOSLINK problem, in that case we can try to install the following driver:
If after you tried all the steps above, the issue persists with the NUC not booting or with TOSLINK, then it could be related to a hardware issue with the NUC itself, and a replacement will be the option to try next.
For that, you can either check with the place of purchase to find out if they can replace it for you, or we can always do the replacement.
If you are interested in the replacement, please get in contact directly with us through chat, email, phone or online support, you just need to select NUC on product type and you will get those options:
Any questions, please let me know.