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The Best Way to Fix Your NES: A Step-by-Step Guide

Here's the original Nintendo Entertainment System. With just a few simple repairs, you can make your NES perform like brand-new again.

Here's the original Nintendo Entertainment System. With just a few simple repairs, you can make your NES perform like brand-new again.

Fixing Your NES

Have you ever tried playing one of your favorite NES games, only to have the infamous “blinking gray screen of death” appear, accompanied by the system’s power light flashing on-and-off as it continuously resets itself? Have your NES games suffered weird graphical glitches, sudden game-crashing resets and picture freezing lock-ups? If you’ve ever owned or played the original Nintendo Entertainment System, chances are that you’ve almost surely experienced one or more of these extremely frustrating problems many times before.

It’s common knowledge now that these and most other NES problems are usually caused by dirty game cartridge contacts resulting from the natural process called oxidation. However, sometimes these problems are caused by or in conjunction with oxidation on the NES's internal 72-pin connector and motherboard contacts. Just like with the contacts on NES games, as the metal of the pin connector and motherboard contacts age, they become more and more oxidized.

Over time, as the oxidation increases, the system's performance when playing games will only get worse. Another common problem is that sometimes the pins on the 72-pin connector become bent out of line, and games fail to make good contact with that part, resulting in a poor connection which causes the game not to play or other issues. Fortunately, these are easily fixable problems.

There actually is a little-known way to completely fix your NES and fix it so well that it will play again, just like when it was brand new! It is entirely possible to restore your NES to perfect working order, and I will tell you in detail exactly how to do this better and easier than you ever thought possible! Just follow my simple step-by-step guide, and you'll have your NES in fabulous condition again in no time!

1. Opening the NES

  • Opening the original Nintendo Entertainment System is a simple process because, unlike most of the cartridges for the console, no specialty bit is required to remove the 6 screws holding it together, nor any of the screws inside it.
  • The screws are always regular Phillips head screws, so all you need to get it open is a Phillips screwdriver with a relatively small head that's long enough to reach the screws inside the 6 wells on the bottom of the console.
  • Once you've removed the 6 screws, pull the bottom half of the console up and set it off to the side.
  • Next, you need to remove the upper metal RF shield, which is held down by 7 screws.
  • Once that's off, there are 8 more screws you need to remove that hold down the NES motherboard and cartridge-loading mechanism.
  • Once those are out, lift up the motherboard and pull out the 3 connectors attached to the bundles of multi-colored wires in the lower-right corner of the motherboard leading to the controller ports and power and reset switches.
  • After those are removed, lift the whole motherboard out of the case and take off the lower metal RF shield.
  • Then take hold of the black plastic cartridge loading mechanism and pull it back away from the board. It should pull off fairly easily.
  • Now just the pin connector should be attached to the motherboard. It's usually stuck on there pretty tight, so you'll probably need to give it a few good tugs or wiggle it with some force to pull it off.
A NES motherboard after its contacts have been cleaned with metal polish

A NES motherboard after its contacts have been cleaned with metal polish

2. Cleaning the NES Motherboard Contacts

  • With the pin connector separated from the motherboard, its metal contacts will be exposed. These usually look extremely blackened and filthy from years of oxidation, and they should be cleaned to maximize your system's performance.
  • Some NES repair guides don't bother with this step, instead just simply telling you to replace the 72-pin connector. However, take my word: it is important to clean these contacts. If they're left dirty, that filth can interfere with the electrical connection between the pin connector and the motherboard, the same way that grime on game cartridge contacts interferes with the electrical connection between the game and the pin connector. This needs to be done if you really want to restore your NES to a healthy, problem-free state.
  • Now to clean the contacts, you're going to need just a couple of supplies.
  • The first thing you'll need is a few clean rags or small pieces of cloth. They don't have to be anything huge, though. I've found that something about the size of your hand or even smaller is actually preferable and easier to work with, so you may want to cut up anything that's fairly large into smaller pieces. If you don't have any clean rags lying around, you can usually buy a small bag of disposable rags somewhere like ACE Hardware for just a few bucks.
  • The second thing you need is, of course, the cleaning substance itself. It's the same oxidation-removing wonder product you should use to clean all your games ...
Brasso—one of several brands of metal polish that can restore your NES's motherboard contacts and 72-pin connector better than anything else

Brasso—one of several brands of metal polish that can restore your NES's motherboard contacts and 72-pin connector better than anything else

Metal Polish!

Any household metal polish is the secret weapon that will have your NES back in tip-top shape faster than you can believe. Trust me—there is nothing out there that will remove those built-up layers of grime on your NES's motherboard contacts as quickly, as easily, and as effectively as metal polish. Brasso and Noxon are two of the leading brands I've used, and I've found that they perform equally well. You can't go wrong with either of those, but any brand of metal polish should do as long as it treats the same seven metals those two work on. A single bottle tends to go a long way, and one is more than enough to do several NES motherboards.

Before you begin using the metal polish, you should take a few minor precautions. Open the windows in whatever room you're in, or better yet, use it outside if you can. You might want to wear a dust mask if you find that the vapors bother you. You may also want to wear a pair of disposable gloves if you have sensitive skin. It washes off easily enough with soap and water, and I've never had skin irritation from it, but that might not be the case for everyone.

When you're ready to start cleaning the contacts on the NES motherboard, just apply some metal polish directly to the contacts, take one of your cleaning rags, and start scrubbing the length of the contacts back and forth with some good pressure. You'll notice right away that the metal polish is removing tons of filth and grime on the contacts, and the cloth is turning dark black or gray, depending on how dirty the contacts were when you started.

Once the cloth is almost totally soiled, dispose of it, put some more metal polish on the contacts, and start scrubbing again with a clean cloth until that one is completely dirty. I recommend repeating this cycle several times to get those motherboard contacts as clean as possible.

Make sure you do the contacts on both sides, whether separately or simultaneously. You want to keep up the scrubbing as long as it takes until those contacts are nice and shiny and show no visible signs of filth. I've found this usually takes at least 5–6 cloths to achieve, and more may be necessary depending on how badly oxidized the motherboard contacts were, to begin with. You should definitely invest a little more time/effort/rags/polish in cleaning these contacts than you normally do on a game.

First of all, you're dealing with a bigger surface area, and secondly, the oxidation on these tends to be quite great, usually a lot worse than most games will look. It may be a pain, but you're probably only going to do this once, so make it count. In my experience, the contacts on NES motherboards are so badly oxidized that it seems you hardly ever reach a point where there's zero gray color coming off on the cloth.

Don't worry too much about that, though. It's almost impossible to get them perfectly 100% clean, but so long as you don't stop until there's just mostly light-gray color on your rag, it's almost always more than enough to make it work. Buff the contacts with another clean cloth, and wipe any excess polish off that may have wandered onto other parts of the circuit board using your rag or Q-tips.

This new NES 72-pin connector is an essential part of every Nintendo Entertainment System, which must be in good condition to avoid gameplay problems.

This new NES 72-pin connector is an essential part of every Nintendo Entertainment System, which must be in good condition to avoid gameplay problems.

3. Replacing or Cleaning the 72-pin Connector 

Now you need to deal with the problem of the 72-pin connector. Fortunately, there's a bit more flexibility in how you can deal with this. You have a choice of two options when it comes to the pin connector, and it's just a matter of preference which method you choose.

  1. Replace the 72-pin connector with a new one. This is certainly the quickest and easiest fix for the problems caused by this part. If you choose to go this route, it's not hard to obtain one of these from numerous online retailers. These are all over the place on sites like and eBay, and they don't cost that much. The regular ones are usually in the neighborhood of $7–$8. You will see some higher-priced gold pin versions out there as well. Yes, gold is a better conductor of electricity, but the cheaper non-gold ones will also get the job done just fine. The most important thing is having a pin connector in your system that is clean and without bent pins, no matter what metal it is. I recommend taking a good look at your system's original pin connector once you've removed it. If it looks like it has bent pins rather than just oxidation, you're probably better off not trying option 2 and just buying a replacement. If it has bent pins, it's probably not going to work, no matter how well you clean it. Bending those pins back into line can be quite difficult, if not impossible, and maybe more trouble than it's worth.
  2. The other option is to clean the original pin connector with metal polish. Contrary to what many people think, you don't have to replace your system's original pin connector if oxidation is the only thing wrong with it. Just like your NES games and the system's motherboard contacts, the metal polish can be used on the pin connector to eat away the effects of oxidation. It's really almost invisible on most pin connectors, but it is there, so you want to clean it if you're determined to stick with your original. If you don't mind spending a little time and effort, this way is certainly cheaper than buying a new one, although it requires a little more work.

If you do decide to clean your original pin connector, you may want to try these techniques because I've found that they work pretty well. The first involves using an ordinary razor blade and some small, clean white pieces of cloth. Fold the razor blade inside a small piece of cloth and put some metal polish between either set of pins on the connector. Then gently push the swaddled razorblade down in between the two rows of pins and begin to drag it back and forth through the channel.

Try to go in a straight line up-and-down the channel as you push and pull the blade between the rows of pins because you don't want to exert too much pressure toward either side and accidentally bend any pins out of line. As the cloth gently brushes the pins with the metal polish, it will remove the oxidation on them. When you pull the cloth up, you should notice black, gray, or green streaks on it from where oxidation has been removed.

Flip the cloth over, use the other side and some more polish, and rub those pins again. When the cloth is too soiled, use a new piece and repeat the process. It's hard to say where you should stop with this, but I recommend repeating this cycle with at least 5 or 6 cloths to give those pins a really good clean.

You might also want to use some Q-tips and gently rub metal polish across the tops of those rows of pins or wipe them with your cloth. Buff them with a clean cloth using the razorblade method to finish up. Don't forget that you actually need to clean two sets of pins here: the row that connects the pin connector to the motherboard and the one that connects the game cartridge to the pin connector. Once you've cleaned both those rows of pins, put the pin connector into the cartridge loading mechanism and re-attach the pin connector to the cleaned contacts on your NES's motherboard.

4. Reassemble Your NES and Test It

  • Now comes the fun part! You're going to want to reassemble your NES about halfway, up to the point where you have just the lower metal shield, motherboard, and all essential parts in there.
  • At this point, I recommend not screwing the whole system back together because just in case the NES doesn't work, it's a pain to have to unscrew the whole system again to fix the problem. Just put the screws in a little cup or something and set them off to the side for a minute.
  • Once you've got everything in place, take a cleaned game cartridge, insert it into your NES, and press the power button.
  • If your game works, then congratulations! You've just restored your NES, and you can look forward to years of flawless play from your like-new system. Go put the top metal shield on over the motherboard, screw it down, and put any other screws back where they belong.
  • Then put the top plastic casing on and screw the system back together. It'll likely be many years before it ever needs cleaning again, so long as you take care of it.
  • Keep your cleaned games in cases or those black plastic sleeves, don't put dirty games in it, and always put the cartridge slot lid down when the system is not in use to minimize the effects of oxidation.

In case it doesn't work, don't panic. It's not necessarily the NES causing the problem. Some games can just be really stubborn about starting up, even when their contacts look all polished and shiny. Most of the time, all they will need is a bit more cleaning to make them work. Try several cleaned games to see if any of them work. If all your cleaned games refuse to play, there are a few things that could be causing the problem:

  1. Try pushing your games only about halfway into the connector and see if they work that way. I've had several newly-cleaned games not work at first, even in newly-cleaned NES consoles with brand-new 72-pin connectors, and as soon as I tried this trick, they started up like a charm. You don't have to shove the game in as far as it will go. Just ease it in there part-way, and this may take care of the problem. It seems some of the replacement pin connectors can be much more finicky this way than the originals, so if you know your system has one, this could be the issue.
  2. The NES's motherboard itself could have a more serious problem, likely stemming from the failure of a particular component, severe physical damage, or liquid spilled inside the cartridge. If any of these are the case, the NES may or may not be fixable. All of these situations are extremely rare, though.

*Important tip: For optimal results, it is always best to clean your NES games before putting them into the system's new 72-pin connector. If your NES games are heavily oxidized, they still may not play even with a brand-new or cleaned pin connector in your NES, and dirty games can transfer oxidation to the pin connector and vice versa. Therefore, it's a good idea to clean all your NES games and replace or clean your NES's pin connector at the same time to minimize future problems.

© 2012 Mr. GameFix