Yes you can use sandpaper on carts

[redtornado]

I was at the store and a customer brought in a nes game that was freezing up. I took out the wad of sandpaper and rubbed on the inside. The look on the customers face was priceless. They thought Id ruined the game. I had to explain that you have to use a very fine grit (1200) sandpaper and don't over sand it. Clean it with rubbing alcohol and wipe dry. Perfect. Guess what? Game worked. With carts, 99% of the time its dirty contacts.

Now if you use sandpaper on a cd, you may ruin it.

Blowing inside does nothing but make you feel better.