Originally Posted by
Oldskool
If it's completely missing and doesn't look like one has ever been installed there, then its probably supposed to be that way.
I don't have one to look at inside or anything. Make sure you clean the contacts REALLY good if they are dirty. If it's just as clean as it can possibly be, and your game boy is working fine then you might just have a bad game.
Take a close-up pic that we can see clearly and we'll be able to tell you if something is broke or not. I would think that if nothing fell out of the cart when you opened it up that it's fine.