Did Blowing Into The NES Cartridge Really Work?
As a wee lad in the last millennium I was an authorized Nintendo repairman.Blowing on the cart sometimes worked, if there was errant dust or fluff in the way. But in the long run the salty moist air would cause a corrosive layer of gunk on the contacts. Normal procedure was to open each cart and clean them with a good eraser then an alcohol wash.The bigger problem was bad design in the original NES. The cart plugged into a component that looked like a harmonica and then pressed downwards, levering against a pretty heavy spring. This perpendicular stress caused the contacts to break, first causing contact flakiness, then failure. The SuperNES and GameBoy fixed this problem with a vertical insertion that carried over into the N64 and others.