Do you only have DDR3 memory installed (nothing in the DDR2 slots)? Also, what model of memory are you trying to install in the DDR3 slots?
i dont have any other ram in DDR2 slot. i already have transcend 4GB ram 1333mhz ddr3. i thought of adding ram in another slot with 4GB 1333 but in the nearby shop i got only 8GB hyperx 1866, in the website it shows that it supports 1866,1333,1600. So i put only 8GB ram as the board supports total of only 8gb ram. but no output in the screen when i started the pc.