Whether you are a collector or a retro fan, you have surely encountered a black screen when playing a title on an NES, strange graphic glitches, sudden ‘resets’ or screen freezes. Most of these issues are caused by dirty contacts on the old game cartridge or in the console, the result of the natural process called oxidation.

Over time, as they are exposed to air, the cartridge games circuits oxidize due to the contact of the metal with the oxygen molecules. This thin layer of oxidation prevents the cartridge contacts from communicating effectively with the console slot, causing errors or failure to play the game.

Inserting dusty games into your beloved classic console is bad for it; likewise, a dirty home console can infect the clean games in your collection. But let’s stop being so pessimistic because we are here to show you the best way to clean NES game cartridges in the most effective way possible.

First Thing To Know About Cleaning NES Cartridges

If you put your cartridge in a dirty console, you will make the cart dirty. If you put a dirty cartridge in a clean console, you will make the console dirty.

One contaminated game or console will quickly spread to the rest of your collection. I can not overstate this enough. Cartridge cleaning is useless if you don’t follow these 2 rules:

  • Make sure your NES console is clean
  • Never put a dirty game in it.

Warnings:

But first, there are a few things you should not do when cleaning cartridges, as they can cause long-term damage to either the game or the console.

  • DO NOT BLOW: by far the most used practice when it comes to cleaning a cartridge, but surely you have not been told that it damages it quite a lot. Blowing accumulates moisture that can cause more reading problems. It may work fine the first time because the moisture from the breath is electrically conductive, but that’s just a stopgap because, in the long run, it will end up damaging the 72-pin connector on the cartridge and inside the NES.
  • Do not clean with water: since it is dirt that prevents the title from playing well, the logical thing to do is to clean it with the element most commonly used for that purpose, water. You should not need to be told this but cleaning electronics with water is not recommended. They are enemies.
  • Only use cleaning products containing alcohol: another widely used method is to use specific cleaning chemicals to remove dirt from the cartridges, although isopropyl alcohol is the only one recommended for this task. While other products may contain alcohol, they also contain other chemicals that leave residues.
The copper pins of a Nintendo NES cartridge

In general, do not use anything that can damage or leave debris in the internal circuitry of the cartridge as you will still have the same reading problem or even make it worse.

Methods to clean an NES cartridge

In this tutorial, we teach two cleaning methods, one more demanding than the other, so we recommend starting with this first method to solve the problem, and if it doesn’t work, jump to the second method.

1st Cleaning Method

For this task, you must first look at the condition of the cartridge. If it does not have a lot of dirt on it and seems easy to remove, proceed with this method. You will need the following tools:

  • Sheet of paper (not recycled because they leave residues)
  • Rubbing alcohol: it is a necessary element to clean the contacts, but preferably with the least amount of water. You want an Isopropyl alcohol with a rating of 70% or more. This special element is characterized by its neatness, as it leaves almost no residue. It is available at any hardware store
  • An old toothbrush

Steps:

  1. Roll a small piece of the paper into a spiral.
  2. Soak the paper roll in isopropyl alcohol.
  3. Rub the contacts of the cartridge with the roll, so that the alcohol cleaner removes the grime contained on the pins. You have to do it with energy, so there is friction, otherwise, you will not remove the residues. Repeat this process with both ends of the roll until they adopt a black color, which means that they have absorbed the dirt. 
  4. Run the brush through the contacts of the cartridge to remove the tiny pieces of paper that are left there. Some people use cotton swabs instead of paper to clean the cartridge, which is not bad but has its drawbacks, they can leave bits of cotton that are more difficult to remove and are not as effective as paper.
  5. Insert and remove the cartridge about 4 or 5 times in the console when it is off. With this, the inner connector of the console is cleaned a little.
  6. After that, repeat steps 3 and 4 with a new roll of paper. 
  7. Finally, wipe dry and insert the cartridge into the console to see if it works. In case it still does not play, we can clean a little deeper.

2nd cleaning method

If at the first inspection of the cartridge, you notice that it is too dirty or even corrosion, or the first method did not work, you can perform this more aggressive procedure. You will need the following tools:

  • Sheet of paper
  • Isopropyl alcohol
  • Eraser
  • An old toothbrush
  • Phillps or Ninitedo security bit screwdriver

Nintendo retro consoles and their respective game casings sometimes use special screws, which you simply cannot turn with a small Phillips screwdriver. For this task, you will need a screwdriver called Gamebit, used for opening cartridges like NES, SNES, N64, Sega Genesis, and Master System. Every retro gamer should have one in their arsenal.

Steps:

  1. Open the cartridge with your screwdriver, remove the 3 screws (or 5) from the case, and expose the circuit board. It is usually covered with dirt and rust, so you will have found the main culprit. However, if the board is not found in this state, proceed with the method anyway.
  2. Roll up a piece of paper and soak it in the isopropyl alcohol.
  3. Once the roll has been soaked, scrub it vigorously over the contacts of the plate. Remember, no friction, no cleaning. Be careful not to touch the components too much, as the grease from your fingers can create residues. At the end of this step, the ends of the roll should be black from contact with the dirt. 
  4. When the alcohol evaporates, which should not take more than a few seconds, you must use the eraser to clean the dirt or oxidation on both sides of the contacts. 
  5. Clean the eraser residues with the brush. 
  6. Use alcohol to clean the contacts again.
  7. Dry the set plate with a dry piece of paper.
  8. Replace the plate in the cartridge, which fits into the plastic “grips” perfectly without forcing it so that it does not move. Then, reinsert the screws gently, because if you tighten too much you can break the casings. 
  9. Insert the cartridge into the console to check if it works.

In case it does not play the game, you must take out and insert the cartridge about 4 or 5 times in the console while it is turned off. Clean the cartridge with a paper roll soaked in alcohol similar to the 1st method. After that, insert the cartridge into the console and enjoy the game.

If the cartridge still does not play after completing this method, the console may have an internal reading problem or the cartridge may be damaged. To clear doubts, you can test the game on another NES. 

Each retro expert has their special way to clean their cartridges, but in general, they all consist of isopropyl alcohol, special screwdrivers, and tools to remove dirt. Hopefully, this tutorial has been helpful to clean your cartridges and you can continue enjoying classic games on your NES, a console that stands the test of time thanks to the love that gamers have for it.