Convert a Nintendo 3DS Dock to USB C


After posting our USB type C board for the Wii U dock, we were contacted by a reader regarding the possibility of creating something similar for the Nintendo 3DS dock. Like the Wii U gamepad, the Nintendo 3DS uses a proprietary charging port, requiring a specific charger/cable.

It’s taken a while to release, but thanks to photos and details send by our reader, we were able to create something suitable.

Nintendo 3DS USB C dock PCB
Bare USB type C PCB for the Nintendo 3DS dock

This board is a near drop-in replacement for the original, though some minor sanding/modifications are required to the inside of the dock due to the physical size difference of the port. Still, it’s far less risky to modify the dock than modding the console itself, which could result in a broken 3DS.

Official Nintendo docks for the 3DS, New 3DS, 3DS XL and New 3DS XL all include the same PCB inside their respective dock, so this design is suitable for all four docks. Just be aware that any required trimming/sanding may differ slightly between the docks due to their different designs.

As ever, the board design (both with and without switch pads) are available on GitHub, so you can have a go at making one yourself. For pre-assembled boards, check out our Ko-Fi page to keep up to date with availability. If they’re not listed, you can get in touch through our contact page.

Removing the Original Board

As is typical for Nintendo handhelds, the dock is held together using tri-wing screws. Remove all six to gain access to the inside of the dock.

Be careful when pulling the two halves apart, as there are loose springs inside. It doesn’t matter if they fall out of position, just be sure not to lose them.

Inside the dock
Inside the dock, with the original board still fitted

The original charging board is friction-fit, with no screws holding it in place. Lift the board off the mounting posts to gain access to the solder pads underneath. You can then desolder the original board from the dock.

Modifying the Dock

The USB type C port is wider than the original. To get the dock to fit around the new port, the lower half of the dock needs to be altered.

Using a file, sandpaper or other instrument, widen the hole roughly as shown below. You can hold the port up to the area to get an idea of the right amount to cut. Alternatively, you can cut this section off entirely, though there will be a larger hole in the dock where the plastic has been removed.

Trimmed outer section
Trimmed section surrounding the USB type C port

You’ll also need to remove some plastic inside the dock. To do this, we’d recommend fitting the new board in place (it should be a tight fit) to allow regular test fits during the process.

Sanding results
The result of our sanding efforts

This is the result of our efforts, though a little more could be removed from around the screw hole. This appears to be the main point at which the board makes contact with the shell – it might not be necessary to trim/sand quite as much of the inside as we ended up doing.

New PCB fitted to the dock
New PCB fitted inside the dock, ready for soldering

Once you’re happy, solder the two wires onto the new board. If you’re using the switch version, you’ll also want to install a switch to the shell at this point. If you have a switch version of the board, you can simply bridge the two pads if you no longer wish to use one.

It’s probably a good idea to apply power to the board, and check the two output pads/contacts are getting the correct voltage. Once you’re happy, you can put the dock back together.

Fitting the springs
Note the position of the springs, which are sat on removable plastic pieces

Note the position of the three plastic pieces, which have the springs sat on top of them. Be careful when putting the two halves back together, to keep the springs in place.

Finished Dock

Here are a few photos of the finished dock. Not the neatest, but this was the first attempt at trimming the dock.

Finished dock
The finished dock

We might look at adding a 3D printed cover to this in the future, just to make it look tidier. Not that it’s visible when plugged in, but we know it’s there.

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