R4 card for nintendo ds

[freak_unique]

Hey i currently have an R4 card for nintendo DS meaning i can download my own games to it. Anyways i was playing a game that messed it up and since it just constantly says "loading" when i start up the DS with the R4 card. Ive tried deleting the game that caused the problem but it still wont work. Does anyone know how i can fix this? maybe format the card and reinstall everything or anything?cheers