I have a new build I set up today with an Asus M4A78 Plus Mobo, Phenom II 955, 8800GT, and 4X1GB DDR2 sticks of PC2-6400 ram. I know that individually all the components are good. If I only install sticks in a1 and b1 it works perfectly, with any combination of ram. Any combination involving a2 and b2 the mobo wont post. Have tried updating bios as well. PLEASE HELP ME!
Need to set ram voltage in bios with just two chips initially to manufacturers specifications which generally are higher than motherboard default voltages. Add additional 2 chips and if they come up test for alittle while.
In some circumstances with may need to up voltage to cpu memory controller slightly. The latest Phenom II 965 stepping C3 is reported to be the first AMD phenom II chip certified for (four) memory modules.