Any chance that your mobo may be shorting-out in the new case? You may be able to hook everything up by placing the mobo on a piece of cardboard outside the case and then powering up to see what happens.
Sometimes a shorted signal path won't cause the p.s. to overload enough to kick the overload protection.
Okay, here is my problem, about a month ago I was upgrading my computer and when I do that I always upgrade my Girlfriends computer with my old parts.. Well this time around when I did this, all I did was transfer everything into a differen't case and now I get no video or beeps!! I have now tried 2 differen't Motherboards 2 differen't AGP cards, 3 hard drives, 2 Powersupplies, and 2 CPU's, I am completely lost here why it still doesn't work!! Anyone out there that can help me?