D54250WYKH won't boot

Version 1

    i buy 10 systems:

         - D54250WYKH

         - Kingston SDD SKC300S37A/60G

         - Kingston 4Gb KVR16LS11/4

     

    And the nuc don't boot (1 in 5 times) and a message "A bootable device has not been detected" appears.

     

    Last bios updated and last sdd firmware updated.

     

    Please help me.