Memory modules are 2 * 8BG Crucial CT102464BF160B (the rig was first set up end of August so has been working for ~4 months)
I tested the following combinations (modules :
- memory module A - top slot: Continuous blue light
- memory module A - bottom slot: Continuous blue light
- memory module B - top slot: Continuous blue light
- memory module B - bottom slot: Continuous blue light
- Both memory modules: Continuous blue light
- No memory modules: Three blinks
I am not from Intel, but am surprised that memory worked for months. Since yours worked for months it may be different issue, but I thought that specific memory module had been tested in NUC and failed. The failing ones have too low memory density (too many chips per side), and maybe the higher density ones have different letters at the end such as J.
according to Intel® NUC Boards and Kits — System Memory, the memory appears under "Customer-reported compatible". Additionally my laptop happens to have SK Hynix HMT41GS6AFR8A-PB 8GB memory which appears under the "Tested memory" list. I've tested this in the NUC and still get the same result.