Is it possible to demagnetise magnetised GBC carts in any way? I'm asking because I stuck a magnet to my Pokemon Gold a while back for no apparent reason, and I wondered if I could actually demagnetise it without causing permanent harm to the cart. I asked my dad, and he thought it couldn't be done easily, but could be done.
none. If it was a floppy disk, then you would be right to be concerned, but game cartridges are solid state media and unaffected by magnets.
Well, before I rubbed the magnet on the cart, it saved fine. But now it doesn't keep the save data, and even if I overwrite it several times, it only keeps it on for one time, then it's cleared. Is it just old?
you rubbed the magnet on it? That is bad. if a wire is in a moving magnetic field (you moving the magnet) then an electric current is induced in the wire. That may have fried something.
I doubt it should affect the electronics. There's a ROM chip in the cart and although I don't know the type of memory, I do know that ROM memories aren't easily changed, so you will be able to play the game. The save part is a bit more tricky. They use a battery in every cart, indicating it's using SRAM. With a magnet it is quite possible that you have erased your data. The induced current of loony's post might indeed have damaged the battery (or save circuit), but I think the current was too small for that. Anyway, it is a stupid idea to try something like that. Don't put magnets near electrical components unless you know what you are doing. Let that be a lesson.