Motherboard was working untill i changed ram frequency from 800mhz to 1333mhz. As it is the speed of installed ram.saved to bios and restart then the pc will not post. Already tried reset Bios. Set jumper to 2/3. Removed the battery. Changed cpu. Power supply. Nothing happens. System power on with green POWER LED. Removed ram. 3 error beep codes. Once ram re installed. No beep code. Ram is cleaned. Dimm slots cleaned. Re applied thermal paste once cpu changed. Still no sign of life...