Cleaning and Repairing

It’s important to note that all of these methods listed below come with some trial and error. You may find one method will work perfectly well on one console only to have seemingly no effect on the next. 

As with using any sort of cleaner, make sure you’re in a well ventilated area and follow any safety precautions labeled on the bottle.

Mainboard Contacts

While you’ve got the 72-pin removed and before you focus your efforts on it, give the contacts on the mainboard a good cleaning. Even though the games themselves don’t ever come in direct contact, the contacts on the mainboard are still subject to having dust settling and build up over the years.

Isopropyl Alcohol works great here along with a cotton swab. Even if the contacts look good to you, checkout the cotton swab after scrubbing them a few times! There’s dirt there!

Make sure to get each contact thoroughly and on both sides of the board.

72-pin Connector

With your NES disassembly and the 72-pin connector removed, the first thing we need to do is do a thorough visual inspection. Take a look at it all around and inside. You may find something completely obvious like a now deceased bug that crawled in to make a home, remnants from previous cleaning attempts like pieces of lint or cotton swabs, or maybe some sort of physical damage like bent or broken pins. I’ve seen some in the aftermath of a failed cleaning attempt where something was shoved into the pin slot which ended up taking out a few pins when it was removed. 

Also take a look at the pin color. It’s likely that the pin ends have a brownish, gold color whereas the rest of the pins are a shiny silver. With age, oxygen, and moisture brings tarnish which will actually insulate the metal pins underneath. Tarnish alone is enough to prevent your game cartridge from being seen by the NES.

Cleaning Methods

Search around the internet and you’ll find no shortage of techniques and cleaner recommendations to restore the 72-pin connector each with their own fans and haters! 

Let’s cover a few of the more popular ones:

Baking Soda, Salt, Aluminum Foil

I put this method first as it’s the one that I’ve had by far the most success with no matter how heavily tarnished the pins were. You may have even heard of this “household remedy” for cleaning silverware and platters: A simple solution of baking soda, salt, aluminum foil, and some near boiling water.

Here’s what you need:

  • Aluminum Foil
  • Small container to fit the 72-pin
  • Baking Soda
  • Salt
  • Near Boiling water

There’s a good change you have these items in your kitchen but if not any grocery or corner store will likely carry them. Any type of salt will do – table salt, kosher, sea salt, etc.

  1. Using a small non-aluminum container, place a layer of aluminum foil along the bottom and sides.
  2. Add 2 tablespoons of baking soda
  3. Add 2 tablespoons of salt
  4. Add 2 – 3 cups of near boiling water (enough to fully submerge the connector)
  5. Stir up the mixture with a spoon
  6. Let the connector soak for a good 15 – 30 minutes
  7. Remove the connector and rinse in warm water
  8. Dry with a fan, hair dryer, or lint free cloth.

Now, I have to disclose that I’m not chemist. How this mixture works and what role the aluminum foil plays in to it, I can only guess. I can attest the results though!

You may find that after drying the connector that there’s some salt or baking soda residue on it. If so, give them another rinse to remove it. I have to note that salt is a corrosive. Don’t skimp on the rinsing!

Isopropyl Alcohol

Probably the most commonly recommended cleaning solution. Anyone repairing game consoles on a regular basis is likely to buy this stuff by the gallon. It’s safe on electronics, helps dissolve grease and fats, and evaporates quickly. Recommended is at least a 90% alcohol solution. 

1. Pour some isopropyl alcohol in a small bowl, but one large enough to fit the connector.

2. Soak the connector for 5 to 15 minutes.

3. Remove the connector and use a small brush (an old toothbrush works great) to give the pins a good scrubbing.

4. Let the connector soak for another 5 to 10 minutes

5. Remove and let air dry.

Isopropyl alcohol, cotton swabs, and brush.

Isopropyl Alcohol works best on those that are only slightly dirty. I use it for routine cleaning. If your pin cartridge is exceptionally dirty, this method may not have a huge effect. I’ve personally had mixed results with this method but it’s a good “first attempt” as Isopropyl Alcohol is fairly inexpensive and easy to find.

Vinegar

I’ve heard this one recommended a few times and have even tried it myself. Vinegar is highly acidic and makes for a great surface cleaner, not to mention a wonderful disinfectant. It cuts into grease and grime pretty quickly but you have to be careful, it also removes the coating on metal surfaces! If exposed to the connector for too long it can cause oxidation on the pins.

1. Poor White Vinegar into a small bowl.

2. Soak the connector for no more than 5 minutes.

3. Remove the connector and use a small brush (an old toothbrush works great) to give the pins a good scrubbing.

4. Rinse the connector thoroughly under warm water to remove any vinegar residue.

You can repeat these steps a few times just make sure not to leave the connector soaking for too long during each cycle. This method seems to work pretty well for light to moderately dirty pins but given the risk of damaging the coating on the pins, I would recommend using one of the other methods listed.

Electrical Contact Cleaner

To be perfectly honest, I haven’t had much luck using circuit board cleaner to remove tarnish on a 72-pin connector but others seem to swear by it. There’s all kinds of circuit board, contact, and electronics cleaners available at your local automotive or hardware store and I’m sure each works to varying degrees. Designed for electronics, this type of cleaner is usually quick drying, non-conductive, and likely highly-toxic. Make sure to follow the instructions on the label.

Nintendo’s Official Cleaning Kit

As an honorable mention, Nintendo released its very own NES Cleaning Kit in 1989. The kit came with all that you’d need to clean not only the 72-pin connector but your game cartridge contacts as well, without the need for taking your console apart. If your cleaning decades worth of gunk it’s probably too late for this kit to have an impact. But preventive maintenance is the easiest kind, so once you get your 72-pin restored, help keep it that way with an original cleaning kit or a newer third-party one. Nintendo recommended cleaning with its kit at least once a month.

Physical Repair

“Re” bending the Pins

This is a bit of a controversial subject. Some would say that years of inserting and removing games has permanently bent or loosened the pins in the connector preventing them from making solid contact with the game cartridge. Others might say that with the Zero-Insertion Force connector, the pins are supposed to be loose and the force put on them when inserting a game is negligible to the long term stability of the pins.

Regardless of which camp you fall in, bending the pins “back into place” is a common repair attempt. Personally, I would follow this only after thoroughly cleaning the connectors and use this as a “last attempt” at a fix.

To bend the pins up you’re going to need something small and precise to get in underneath each pin and slightly pull it up. A dental pick works great for this if you have one, if not a paper clip or safety pin works too. You may even have a small precision flat-head screwdriver to use. Try a few different tools and find one that seems to work best for you.

You’ll want to start on one end of the connector and work your way across each pin, one by one. With your tool of choice, gently angle it underneath a pin, and bend it upwards. You don’t want to bend it all the way up, make sure to leave a little bit of room between the plastic and the metal pin. Also make sure to bend them each evenly. You don’t want some pins to be too high while others are too low.

Using a dental pick to bend the pins.

Boiling the 72-Pin Connector

A more recent trend from those in the “pins are bent” camp is boiling the 72-pin connector on a stove. The idea behind this is that the heat will “relax” the pins allowing them to take their original form and position. Admittedly, I’ve only tried this one time and to a failed result. It’s possible that I didn’t boil them long enough or the tarnish, which boiling will not remove, was too great.

The nice thing about this method is that it doesn’t require any special cleaners or ingredients – just water and a pan.

  1. Fill a sauce pan or similar with water.
  2. Bring the water to a boil on a hot stove.
  3. Submerge the 72-pin connector fully.
  4. Let boil for 30 minutes.
  5. Remove 72-pin connector.
  6. Let air dry and cool.

Game Cartridges

Overlooked far too often are dirty contacts on your game cartridge. It doesn’t matter how clean your 72-pin connector is, if your game is covered in built up gunk it’s probably not going to work – not to mention you’d be shoving said gunk right in the pin slot! I can’t stress this enough. Clean your games! The brass contacts on your cartridge should have a shine. If they’re looking kind of dull, even if you don’t see obvious signs of dirt built up, it’s time for a cleaning. There’s dirt there!

For best results, you should take the case apart so you can have full access to the game’s contacts. Depending on the game and when it was manufactured, there will either be 3 or 5 screws of either a flat-head type or “gamebit”. You can pick up a gambit for only a few bucks in our shop: “GAMEBIT” HEXAGONAL SCREWDRIVER BIT (4.5MM AND 3.8MM)

NES “3 screw” case.

Cleaning Methods

Isopropyl Alcohol 

Tried and true, Isopropyl Alcohol makes an appearance here too. For most cleaning, this is probably all you need – it’s quick and effective.

1. Soak a cotton swab in isopropyl alcohol

2. Rub the cotton swab back and forth along the contacts and on each side of the game board.

3. Repeat with a new swab until there’s no longer residue on the cotton.

4. Let the contacts air dry for a few minutes.

Brass Polish

For games requiring a deeper cleaning, it’s best to use a brash polish.

1. Place a small pea-size amount of brass polish on a lint free cloth.

2. Scrub pins back and forth and on each side.

3. Repeat with more polish until clean.

4. Wipe any remaining residue with a dry cloth.

5. Reassemble the game cartridge.

Brass polish.

Disabling the Lockout Chip

This is where things get a bit ugly. You’ve cleaned the connector every which way you could, you boiled it, poked and prodded it, bent the pins… and it still doesn’t work. The same blink red light. Well, it’s possible that the lockout chip mentioned earlier in the article is faulty.

Disabling this foul chip is not necessarily difficult but it can be a bit nerving since it involves purposely damaging the mainboard. But if you’ve tried everything else, what do you have to loose at this point?

What you’ll need to do is cut off or pry out pin number 4 on the lockout chip so it is fully removed from the chip and/or mainboard. To do this, a small pair of wire cutters works ideally. If you don’t have those, prying the pin our with a dental pick or small flat-head screwdriver will work too.


We’ve covered a lot but time to wrap things up. Some closing thoughts and tip await in the final section.