Replacing the 72 Pin to fix your Nintendo Entertainment System

Posted by on Apr. 30th, 2014

One method for addressing problems for your NES, which has become popular in recent years, is to replace the 72-pin connector which links together with the NES video game cartridge with another made in precisely the design of the original. What follows is a set of informational images and steps for replacing the 72-pin connector in your classic NES system with a new one. Each image can be clicked to access a larger version for more detail.

Step 1: Preparing for the Task

Required for this task is a Phillips #1 screwdriver. Before beginning the procedure, inspect your new NES 72-pin connector. Specifically, check that the outer left and right flat pins are properly aligned. These pins are light gold in color, and should be aligned with the rest of the pins. If they are not aligned properly, you can use a paper clip to move them back into alignment.

While working with the NES, we want to avoid any static discharge which could damage the system. The NES is not as susceptible to such trouble as a newer circuit board or computer system, but you should avoid, for example, wearing fuzzy slippers on the carpet while installing the connector.

Step 2: Opening the NES Case

In Figure 1 you see an image of the original “toaster oven” style Nintendo Entertainment System. The first step in replacing the 72-pin connector will be to open the primary casing around the NES. First, turn the system upside down, and look for a set of six (6) screws which hold the case together. The locations of these screws are shown in Figure 2. After removing the screws with a Phillips head screwdriver, turn the system back onto its bottom, and carefully remove the cover, which should slide up and off easily. Be sure to set the screws aside where they will not be lost. I tend to place them into the cover of the NES for safekeeping.

Step 3: Removing the Shield

After removing the cover, you should see a system which appears much as the image in Figure 3. The innards of the NES should be covered in a metal casing which serves to prevent interference either to or from the electrical components of the NES. In order to access the 72-pin connector, it will be necessary for us to remove this shielding. The shield is held in place by seven (7) Phillips head screws, which can be readily removed. The locations of these screws is shown in Figure 3. After removing these screws, pull up on the shield, and it should come entirely free. Set it aside, along with the screws which hold it in place, and proceed to the next step.

Step 4: Removing the Cartridge Housing

Once the RF shield has been removed you will see the black plastic cartridge housing into which the game cartridges slide. To remove this, first remove a series of six (6) screws which are identified in Figure 4. After the screws have been removed, lift up slightly on the circuit board with your fingertips, and pull the unit up slightly and out towards the front of the system, as shown in Figure 5. Removal is simple, but when reinstalling the cartridge housing, note that there is a plastic clip which fits under the circuit board. Be careful to place this clip under the board during reinstallation, or the housing will not sit properly within the NES system.

Step 5: Removing the 72-pin Connector

At this point you can see the old 72-pin connector. In order to remove the connector, it will be necessary to loosen the screws holding the circuit board and power supply to the case. These screws are identified with red arrows in Figure 6. Loosen the screws about half way, it will not be necessary to remove them completely, though you can if you so desire. After loosening the screws, use your fingertips to lift up slightly on the circuit board, and press firmly on the old 72-pin connector using your thumbs on the sides of the plastic connector. The connector may be held very tightly to the motherboard, so you may need to press very firmly.

Once the connector has slid off, you will see the pins beneath to which the connector was contacted. This is shown in Figure 7. At this point you can set the old 72-pin connector aside.

Step 6: Installing the New 72-pin Connector

To install your new 72-pin connector, simply line it up with the pins exactly as the old connector was, and press it firmly into place. At this point, the system can be reassembled by reversing the procedure outlined above. When reinstalling the cartridge housing be careful that the plastic clip fits beneath the circuit board, or the housing will not sit securely, and you may notice a gap between the cartridge housing and the circuit board.

Step 7: Clean your Cartridges and Test

Be sure to clean your video game cartridges before testing them with the new connector! Use of dirty game cartridges will only serve to dirty the new connector. If you have an NES cleaning kit, it can be used to clean your cartridges. If you do not have a cleaning system, there are a variety of opinions on cartridge cleaning, but in my experience, rubbing alcohol solution (50/50 alcohol and water) on a Q-tip will do a decent job of cleaning the ends of the cartridge contacts. Also, until you have tested and broken in your new 72-pin connector, avoid using some first-generation NES games, such as “Mario Brothers/Duck Hunt” and “Super Mario Brothers.” These older games can have a thicker board which may damage the new 72-pin connector before it has been broken in.

Once your cartridges have been cleaned, try placing one into your NES system. You should notice that the connection is much tighter than it used to be. This is normal, and will become less over time as the new connector is broken in. If you continue to have trouble with the setup process, feel free to contact me with questions.

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