Haha...I've had so many systems that wouldn't boot that all I did was re-seat something and it magically worked. Sometimes it's RAM, others it's a PCI card. Heck, I remember a long time ago I had a modem that just all of a sudden stopped being recognized by the system. I pulled it, popped it back in, no luck. A friend said "rub a pencil eraser on the pins" so I did. Popped it back in, viola, worked again. No idea how...just figured it was akin to the "blow on the Nintendo cartridge" trick, lol.
Finicky bastards, these computer things are, lol.