Hi all!, I have four RAM slots. 1GPx2 slot (1st slot and 2nd slot) is already come with the computer. I recently bought a new RAM 4GPx1 card to upgrade my computer. I installed it onto my 3rd RAM slot correctly without removing old RAMs. Now, my monitor won't display anything at all, not even the BIOS screen. I removed the new RAM card and try my old one in and it still won't display anything. I also changed into different RAM slots but the result the same I did my research and the two RAM cards that I have are exactly the same beside the differnet manufacture company. I also clean my RAM slots and also check/clean the video card. It still not displaying anything! please give me some advice..