Major problem need help

K so today i went to my brother in laws to get ram put in, got it put in turned it on everything worked great all the ram was added up everything was there. There was a problem with my nephews computer so i was going to check his graphics card if it failed or not so i unplugged mine but i didnt take it out or anything because he got it working at the last second before i took it out. Anyway, after that i plugged it all back in didnt check it though to see if it worked or not. So i take it home and here comes the worst easter ever, the computer turns on but i have no display image i checked the cords, even took out the ram i added in thinking that was it but it wasnt, checked the graphics card and it was plugged in yet no display image. What is going on?! K just now i plugged it through the mother board and not through the graphics card and everythings working but the graphics card ports dont work any ideas?