I just received a DN2820FYKH NUC. I installed a

Kingston Technology 4GB 1600MHz DDR3L PC3-12800 1.35V Non-ECC CL11 SODIMM Intel Laptop Memory KVR16LS11/4

& a Toshiba 2.5" hard drive. I connected it to a Samsung PN50A450 TV (which supports 1024x768 resolution). When I power it on it produces no display when connected directly to the HDMI input of the TV. It reboots after the power light on the NUC is on continuously for 30 seconds, and continues this on for 30 seconds & reboot cycle until turned off.  I have tried it on two Logitech keyboards & pressed F2 & F10 during boots. Still no display. Any suggestions?