3D Printed Top Load NES Mod – Final

Part One can be found here… 3D Printed Top Load NES Mod – Part One

and part two… 3D Printed Top Load NES Mod – Part Two

and part three… 3D Printed Top Load NES Mod – Part Three

This took a lot longer than I was hoping. I’ve been procrastinating some. I think anyone that had to rewire the cartridge connector on the NES would feel the same. Soldering the wires to the connector and mainboard isn’t that bad really once you get a rhythm going. The worst part is prepping the 72 wires, one for each pin. Cut to size, strip both ends, twist the bare wires, and finally tin the wires so they’re ready to solder. Wonder if I could buy pre-tinned wires…?

cheesy stock photo

MFW I look under the lid

When rewiring the 72-pin there are a few things to note. With this mod the cartridge connector is flipped. Also, there are 36 pins on each side and the inner pins require a long soldering tip to get in there without making a mess. You will need 24 AWG wire or smaller. Single core kynar wire would probably be best, but I only had some cut up ethernet cables on hand. I soldered the wire to the inside pins and pushed them through to the back between the pins alternating a solid and white color to make it easier when soldering to the main board. This part is relatively simple if you’re newish to soldering: just a tedious process due to the sheer volume of connections that have to be made. Pre-tin all of your pins on the connector and main board and it will make the wiring a breeze (relatively…).

painted nes top load

Here it is all dolled up

It is done! I’m happy with the overall strength of the structure. I’ve had good success even printing at a thin two-wall thickness. At three or four walls this thing could survive a grenade blast. The design is a throwback to the original with a little modern twist, but nothing too gaudy (I hope).

painted nes top load on shelf

Looks good on a shelf too…

The most important part, the reliability of booting a game, has seemed to improve. I’m not a scientist, so you’ll just have to take my anecdote in lieu of an essay. I had a stack of 10 games I tried and only three didn’t want to boot. Out of the other seven, the most trouble I had was having to reinsert the cartridge a couple of times. Keep in mind that I source a lot of my collection from trades, thrifting, flea markets, etc. I cleaned the stubborn cartridges with the back end of a toothbrush that has a soft silicone grip. You can use anything similar, including pencil erasers, to friction scrub the contacts with no need for solvents. After a quick clean, two of the three booted up on the first go (the third had to be reinserted once to get it to work).

rude little guy

No more indecent acts will need to be performed anymore just to play your games

I’m confident that this mod provides an increase to the reliability over the standard front-load design. No more having to cram a game on top to get the perfect angle to get rid of that damn blinking screen. Even with the same stock 72-pin connector that came with this 1987 model NES, I’m seeing good results. Games work first time 49 times out of 50 (make sure to clean your carts) and the hardest I had to work to get a stubborn game to load was to re-insert the cart once. You can even take it a step further and refurb the stock connector, replace it with a modern connector (not guaranteed to fit my design!), and/or disable the region lock chip for even better results.


If you’re a more experienced maker who’s ready to take on a new project, check out my STL files for this project in the shop: gotta keep plastic on the spool so I can continue to prototype new designs!

If you’re still looking into trying this yourself and have a soldering iron – but lack the 3D printer – you can get the STL files and take them to your preferred print shop, or have me print it for you.

If you don’t have time for any of that, I am offering a modding service. I can source an NES or you can send your machine to me (pay postage one way to me, return will be included in checkout). I aim to keep prices reasonable so this mod can be enjoyed by as many nerds as possible.

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