My GBA nor my NDS will not notice the game. It worked before but now it does not. I tried to put a game into it but it took a while to get it in the Gameshark, it worked for that; I believe so. Help please, I have no idea what happened

Please be aware that the GBA and NDS have different Gameshark. You cannot play NDS game with GBA Gameshark and vice-versa.

No, I am using my NDS to play my GBA games and use my Gameshark Sp (for my GBA games)

Sound like you might have killed your Gameshark.
Did you happen to do any of the following:
1. Took out the game while the GBA/NDS and Gameshark were on and in the middle of the game.
2. Took out the Gameshark while on and running.
3. Switched the Gameshark on while the game was running.

Also check if some of the pins in your Gameshark are not bent or torn.

Also, if you could specify whether or not there was a warning screen that appeared the last time you were able to successfully boot the cartridge. One of the more common causes of the problem is activating too many codes simultaneously, and if there were, then it gives a warning message asking you if you want to continue or not.

@gameboy:I did none of those but 1 of the pins are missing so that may be the problem

@Kyuubi: There was no warning screen

That is why you are experiencing that problem. You can get the one you have replaced if you still have the warranty, which also requires the pin code of Gameshark (received with the purchase of Gameshark) and a receipt. If you don't have a receipt and warranty then you have to get a repaired. Call Tech Support on how to get it repaired. Remember to call them during the day and at hours mentioned. They are closed on Holidays. http://forums.gameshark.com/index.php?showtopic=64

Thanks