Just pulled out of box? The NUC7i5DNHE is a computer kit only. First you need install some SO-DIMM DDR4 memory, SSD and you can also add HDD. Then you should install Operation System - like Windows 10. Only when you have this completed you can switch the computer ON (while connected to monitor) and you will see video. However, as a minimum requirement to see some video output generated from BIOS firmware you should install RAM memory.
1. You have one NUC7i5DNHE with RAM and HDD installed?
2. Can you specify in more details your hardware configuration?
3. What is P/N of the SO-DIMM memory?
4. What is the size of memory?
5. Are you have one or two memory modules?
6. What is your storage configuration -SSD, HDD? P/N?