Quoted from RTS:
I pushed the card and reinserted the card. I removed the ball from ther base so I can see the pins clearly. I've reinserted connector 10 times.
I don't know what happened. It was working but I removed it to readjust the bracket and when I put it back in, it didn't work anymore. Crap.
Wire is loose or disconnected from one side or the other.
Maybe a broken/loose wire inside the connector?