If that old NES of yours has died, odds are the culprit is a 72-pin connector. Luckily, it’s easily fixed, as this video from Wired shows.
And how’s this for an embarrassing admission: I never knew the pleasure of having an NES because of my parents’ strict “video games will rot your brain/no son of mine…” mentality. Once the SNES came out, though, all bets were off. My dad would stay up late into the night playing Super Mario World, beating levels for me that I couldn’t.