I just installed 16gb (4x4) of dominator platinum (1866) on my sabertooth Z77 and the red led next to the memok button is on. i also am getting no display on my monitor. i heard that if this happens i am suppose to press the memok button or hold it down or something. i am just not sure.
check your bios rev of the zabertooth mb. if it old ie bios the shipping bios was rev 80x. the newest rev with all the updates is bios 1708. i would use the usb flashback port and flash the mb bios to the newest rev..