Hi there,
It is possible that you need to put the drive in AHCI mode, because IDE may not be supported by your NUC. Additionally, I would try to confirm that the HDD is working and is accessible, just to exclude hard drive issues. If you have the opportunity, you can try the device on another PC. You may be totally right and you are facing some power issues, but I would start with checking the HDD. You can go even further and, while on another PC, check it with Data Lifeguard Diagnostics (which is WD software). I leave you details below.
http://wdc.custhelp.com/app/answers/detail/a_id/3592– some more information about AHCI mode
http://support.wdc.com/product/download.asp?groupid=810&sid=3&lang=en– Data Lifeguard Diagnostics
Hope this helps
