The electronics for an NES system and many of its games are over 25 years old. Every once in a while a game just won't work for a number of reasons. Here are steps you can take to identify what is wrong, and correct the problem.
1. Only Use Clean GamesWhen you use your NES, ONLY USE CLEANED GAMES in the console. This prevents dirt and dust from entering the console and causing a malfunction. And since these electronics are 25+ years old, it's wise to keep it clean.
Here is an effective method to thoroughly clean your NES games. I have used this method and it works on 99% of my games. I use Brasso brass polish, and Windex glass cleaner.
NES Game Cleaning Video
http://www.youtube.com/watch?v=xEqhgTqvV0Y2. Don't blow into the games.Blowing into the NES cartridges deposits moisture onto the game contacts. This moisture is likely to permanently corrode the connectors, which facilitate grime rubbing off onto the NES system's connectors, requiring you to clean your NES system to play any game. If it is dusty or dirty use the above cleaning method or use a can of compressed air.
3. Avoid leaving game in the console for extended periods of time (weeks). When you're done playing your NES game, take the game out. If the game is left in for extended periods of time during non-use, the connectors of the game can bend the NES systems 72 pin connector. A severely bent 72 pin connector will barely touch the game and fail to play it.
4. Refurbished systems sometime play games better when the game is in the up position.If your NES has a refurbished or new 72 pin connector and it blinks, try wiggling the game left and right a bit to ensure a good connection. Sometimes new 72 pin connectors work better in the up position rather than the down position. You can tell if the the NES has a new 72 pin if the game fit is tight. Over time, it will loosen up, and the game will work just fine in either position.
5. After several years of play, an NES may require another cleaning and new 72 pin connector.As indicated above a the 72 pin connector of an NES may become bent enough that it doesn't touch the connections of an NES game. You can either replace the 72 pin connector or refurbish it. Below are two tutorials to address each method.
Replacing the 72 pin connector
This one is pretty fool proof. Again, I use Brasso Brass Polish instead of "paste" and I use Windex Glass Cleaner instead of alcohol, since it doesn't leave a residue on the metal.
PART 1 http://www.youtube.com/watch?v=bq5sDmbDIdsPART 2 http://www.youtube.com/watch?v=ZjXkBJcVix0PART 3 http://www.youtube.com/watch?v=11e2VWmH_08Refurbish 72 pin connector
In addition to bending the pins back into place, I use a toothbrush and Windex to clean them up a bit. Make sure to system is totally dry before plugging it back in.
Refurbishing tutorial
http://www.youtube.com/watch?v=1MgD_U8ymkk6. Have fun playing your CLASSIC VIDEO GAMES!!!
