Opening an NES Cartridge
If you’ve been collecting NES games for any length of time you’ve probably come across some cartridges that could use a good cleaning, but when you go to open them up you find that these aren’t any ordinary screws. Nintendo uses special 3.8mm security screws on their cartridges instead of standard phillips or flat head ones you find on most products. To open these you’ll need to purchase a 3.8mm security bit from either eBay, Amazon, or retro video game specialty stores. I recommend purchasing a pack that comes with the 4.5mm security bit as well, which can be used for most other video game consoles.
If you need to remove 5 screws from the back of the cartridge then the two pieces of the shell will simply lift away from each other and you’ll now have access to the board. If you had to remove 3 screws then you’ll find 2 plastic hinges on the top of the cart. To separated these you’ll pull the bottom of the cart directly apart while swiveling the top until the clips slip out.
Once you have access to the board, you’ll find that it is being held in place by some plastic pegs passing through some holes on the board. Simply lift the board straight out and you’ll now have the NES cartridge completely disassembled.
Hopefully, this will help you keep your NES collection well cared for and keep those games running like new.