Haha, I know how that goes... Apparently you're not supposed to Blow into your NES/Games... it damages them.. but it works I tell you! Who the hell was the first person to come up with that idea anyway?
"Hmm.. Maybe if I ..blow in this.. it'll work! Oh wait.. it didn't... and now there are random flashing colours."
Remember the random colours? Or when you'd push power and the title screen would pop up but then disappear and pop up repeatedly? That was irritating.
If you put the power on and then hold down reset for 5 seconds, it usually fixes that random popping up of the title screen though...
The trick was, when you put the game in, push it in and hold it towards the right side of the nintendo! Once it's in, Press down slowly and hold it in for a bit and then let go. It works 85% of the time!
I also used to wedge a piece of lego in there to hold the game down.. surprisingly it worked more often than not.
If those 2 steps fail,
Game Genie was always a great way to get your game workin'! Well... Sometimes....
I hated losing all my saved files on Zelda...
It happened so often... I always had my Final Fantasy files though...