A partial update to this post; a few days ago I finished completely restoring my Nintendo Entertainment System and all of the games for it. I followed this most-excellent guide for the basic steps.
In summary, I:
- Replaced the 72-pin connector inside the NES console;
- Dusted the inside of the console;
- Mr. Clean Magic Eraser'd the console and the outside of all the games;
- Polished all of the game connectors with Mother's Mag and Aluminum Polish;
- Replaced the CR2032 batteries in my two Zelda games (I & II).
After replacing my 72-pin connector, games loaded instantly about 50% of the time. After polishing all of the game connectors, games loaded instantly almost 100% of the time. I still almost can't believe it; it's like playing on a brand-new system.
Can't recommend the Mother's Mag and Aluminum Polish highly enough. I got a mirror finish in the copper on most of the game connectors:
Beauty. If anyone wants to come over and play RBI Baseball, Super Mario 3 or Ice Hockey, drop me a line :)