Hi!
So, only Pokémon Y doesn't load? It could be the ROM, could be a short on the board, could be a lot of things...
You can open it up and inspect it, but the chance is really small that you will get it working.
In my opioning, is it for the best to buy another copy of the game. Usually the parts are also difficult to find.
If the game doesn't want to save anymore, this can be fixed with soldering and a new IC, but that's it I'm afraid.