New Nintendo 3DS XL motherboard swap

The Super Famicom is a contender for my favorite game console of all time.  I loved the North American redesign as the Super NES, but the Super Famicom was what I fixated on for years leading up to its release.  Everything from the contours of the console to the colors of the buttons on the controller seemed so lovingly and carefully designed.  Nothing before or since has really come close.

So when Nintendo announced in early 2016 that there would be a limited edition New Nintendo 3DS LL (that's what the XL is called in Japan) to celebrate the anniversary of the Super Famicom, I immediately pre-ordered it from National Console Support, then dutifully waited 8 months until it arrived.  Whenever a new 3DS special edition is announced in Japan, there's usually a bit of uncertainty about whether it will also come out in the U.S., but this one was clearly not going to be brought here.  It's doubtful most Americans would even recognize what it was supposed to be.

When it arrived, I was thrilled.  Even the product box was a callback to the original Super Famicom box, with the simple stylized stencil design and gray background. 

But enough about that, the N3DS Super Famicom edition is awesome, etc.

Problem is that Nintendo, in a colossally frustrating and reviled move decided that the 3DS would be their first handheld ever to be region locked, so basically I had this cool handheld that would only play Japanese games.  I don't actually own any Japanese 3DS games, and what I really want is to play my US games on this system.

In olden times when we wanted to get around a region lock, we bought and installed mod chips or used boot disks, and more recently used softmods.  Unfortunately Nintendo did a really thorough job of embedding the region lock.  There are, apparently, a couple of region bypass methods for the 3DS, but they all require that you be on some old version of firmware and never update your system, and/or that you have a copy of some obscure game like Cubic Ninja which is only expensive because people want it to help trigger an exploit.  These hacks are involved, not permanent, and always in danger of getting patched out in a future firmware release.  What's most ridiculous about all this is the fact that even flash carts which allow you to play illegally copied games all day long are STILL stymied by region locks.

So the next best thing is to put a U.S. brain (a.k.a. motherboard) into a Japanese 3DS.  When the New 3DS XL was brand new this was a pretty expensive proposition as the only way to get such a motherboard was to buy a domestic New 3DS XL.  However after a year or two a lot of these have been damaged to various degrees and you can get a broken one much more cheaply.  In my case a repair shop was parting out broken units and I was able to get a working motherboard for just over the price of a new game.

The process of transplantation is straightforward but a little tedious. There are plenty of guides online about teardown, and even some videos showing disassembly and reassembly but they're all very terse and leave out little nuances.

There are over a dozen delicate little connectors that need to be carefully removed before the old motherboard will come out and almost all of them are attached to flimsy little ribbon cables.  Every instruction I've ever read that involved removing or replacing ribbon cables came with a stern warning about how easy they were to damage and basically made it seem like they were made of tissue paper. I've done a lot of repairs where I had to twist or pull on the ribbon cables to get them into position, and in a couple of instances I've accidentally pulled too hard or twisted one badly enough I was sure it wouldn't work when everything was back together, but in every case they were fine. I've never actually damaged one. Maybe that's because all the warnings made me extra careful?

Anyway, there are several different types of connectors and they each have to be removed a little differently.

The L and R button clusters are connected to the back of the unit with little sockets. You can pry them up easily with a fingernail or small flathead screwdriver.  The cart slot is also connected to the motherboard with a larger version of the socket connector.

The WiFi antenna (the red wire) is a connected by a standard socket - the same kind you'd see in a laptop.  It's pretty sturdy, just pry it off.

There are four kinds of ribbon connectors - I've color coded them in the image above.

The narrow all-black connectors (outlined in red) just use tension - gently pull them straight out and gently push them straight in. For the narrow black connectors with a large hinged gray lever (outlined in gray) gently pry up the gray lever from the opposite side of where the cable is inserted and the cable should just slip out. (The analog stick ribbon is folded over one of these - you'll need to unscrew the backing for the analog stick and pry it up before you'll be able to get at its ribbon connector.

The wider levers are color-coded according to which direction the connectors should be inserted. The dark sockets with light colored levers (outlined in blue) indicate the ribbon needs to be inserted contact (i.e. shiny) side up.  The light colored sockets with the dark levers (outlined in green) indicate the ribbon needs to be inserted contact side down. There are two wide levers not shown in the picture that are underneath the board in the upper-right corner. One of the two on the back side will actually fit either way - be careful and follow the color code.

The trickiest part of getting the thing apart and back together involves the 3 ribbon cables going into the hinge in the upper right (as your face the back). These ribbon cables are literally right on top of each other and have very little slack to work with.  What's worse is that they are constantly in the way of each other when you try to reassemble them.  (I had to resort to using a sliver of tape to hold one of them out of my way while I worked on the first ribbon.) If you don't have small fingers (and I very much don't) you'll definitely want a good precise pair of angled tweezers. The ribbon on the very bottom (on the underside, the longest of the three that connects perpendicular to the others) is jammed into the hinge recess at an odd angle so when it comes undone, it's not intuitive how it's supposed to go back in.  This is where the color coding for the connectors comes in really handy - it has a black hinge on the socket, so it's conductor side down (in relation to the surface of the board).  I strongly recommend taking pictures before removing the ribbons so you have a reference for how to fold them back in.

If it's not obvious from the subtext, I managed to insert one of the ribbons backwards and the result was that when I turned the system on, the power light would come on and after a second or two there would be a low pop and the system would power down.  Fortunately this didn't cause any apparent damage.  When I fixed the cable orientation everything came up normally and has been working perfectly for a couple of weeks with no issues.