First off, you should have case fans, altough it might have worked it's still better to have them.
And yeah i know what probably happened, There might have been a static charge on that ram by accident, when you put it in the slot it will probably have killed your motherboard. I'm sorry man but i'm pretty sure your mobo is broken...partially since he leds still work but some of the other parts on the mobo will be dead. I can't be 100% sure about this but I do think this is why your pc doesn't work