Heh, I actually just came back upstairs from doing that, and it works without the aux-in board installed. I'm going to go back in and make sure all the ribbons are facing the right way and are in the right places. I'm almost positive I had them right before, seeing as I tried reconnecting them multiple times.
Edit: No success. When I put it in with Aux-In board, cd will not load. Without Aux-In board, it loads.
Edit 2: Possible defect?