I searched the forums, and I didn't really see anything related to my issue here.

So my SNES is from 1994. Some games works on it, some don't. I've cleaned some of the games with alcohol, but have not taken them apart. For example, Super Mario Kart works, until you press the L button and then the graphics get really messed up. Super Mario World works until the map screen comes up, which has garbled graphics as well.

So my question is, could it be the system, or the games? Is there a way to clean the SNES without taking it apart?