Things that are above with the wrong post:
1) A game Genie on the NES. This one is so absolutely wrong that the wording in the above line got screwed up. This is what happens to your cart reading pins after using it once. The next line demonstrates what happens after repeated use.
GREEPSINTLY OUT OF PORK CHOPSCLE THE NULED IS CUTINGS CHEESE PORREMBER YOU HAVE DIA
And then it stops working with carts only; it will only work when you have the GG inserted.
2) Inserting random codes. DO. NOT. DO. THIS. You will see why in 4.
3) Once random stuff happens like in PIGPOG, you should definitely turn your console off.
4) Random in-game codes are able to screw up your console; GG ones are just as dangerous. Don't believe me?
This will screw up your console, even if you're playing the GBA version.