RAM chips are not suitable problem

I am posting here because I believe that you guys can solve this problem of mine. I inserted my VGA into another PC and it functioned properly. However, the screen did not display any signal. I have a feeling that maybe the RAM chips are not suitable for this, since they appear to be quite small. Do you think I need DDR3?? I also exchanged RAM cards with other PCs and tested the VGA, but it is still the same. By the way, all the fans work, and everything is switched on. The connections are secure as well. Do you think my VGA’S Mobo slot might be broken??
