Strange. Could be the contacts in the slot. If i had a NES with this problem i wouuld clean the hell out of it. Buut yeah, i remember the blowing trick and used it myself back then. Today i rarely use it.That's the thing: the contacts didn't need cleaning on any of the games, they're about as shiny as a brand new car. Still couldn't get any of them to work by simply inserting them. I remember similar experiences with even brand new NES decks back in the day, so if you ask me, the console really is just that finnicky.