The fan no longer spins freely.
It seems the only option is RMA the entire unit?
This unit date of manufacture 04/2016
Thank you for contacting the Intel community.
In this case, if the fan for this NUC failed the only option is a replacement, you could try accessing the BIOS and then press F9 to set the BIOS to default settings and then press F10 to save the changes, if that does not work and the fan does not spin at all then it needs to be replaced.
You can contact support to request a replacement, please bear in mind that there is three years warranty for this unit.