I dunno about cheat devices corrupting actual game data, from what I undefstand, the cartridges are read only memory inserted into the ram during play, the
cheats store certain fixed data inside specified memory address in the ram, the save file is stored in a non read only storage inside the cart that is kept active by a battery back up (like the silver see through button in the pokemon sapphire and ruby GBA carts... Or is that the game clock)
You usually load the cheat device before the game so you can tell what address to change the valued to, then load the game and play to notice the desire effect. Is very basic modifications. Actual corruption of the game requires alter data on cart which
cheats never do. Anyway sorry if it doesn't work. Did you try cleaning the contact connetors?