Mayflash Wii to NES fix tutorial

This is a continuation to my Mayflash NES/SNES to Wii Adapter article. Please read that first.

This tutorial will instruct you in how to build yourself a Mayflash NES/SNES-to-Wiimote controller adapter with a full fledged standard 7-pin NES connector instead of the provided DB-9 pin connector.


Note that since the writing of this tutorial, Mayflash has begun to include DB-9 to NES 7-pin adapters along with their controllers. Still, if you don’t want to bother with the adapter, this is still a good read.

By default, you can only use SNES controllers and DB-9 Famiclone controllers.


Q: Huh? NES 7-pin? DB-9? I’m confused.

A: In the 1980s, many videogame systems including the Atari 2600, Commodore 64 and even Sega Genesis used a standard nine pin controller port called a DB-9. This meant that many controllers were interchangeable with each other, allowing gamers to use Genesis controllers to play Atari games.  The NES used its own connector. This mod involves removing the DB9 connector and replacing it with an NES 7pin connector.

Q: That sounds hard! What’s so special about the Mayflash adapter anyway? Why not just use Retrozone’s Retroports?

A: The Retroports that Retrozone sell are marketed as NES & SNES to Wii adapters, but they are in reality only NES & SNES to Gamecube adapters. This means that they work on all Gamecube games that support digital control, but on the Wii they only work with games that alllow the use of Gamecube controllers. Increasingly, more games are being released on the Wii that support the Wiimote on its side and Classic Controller only, such as Megaman 9 and Megaman 10. Also, since the Mayflash adapter plugs into the Wiimote and not the Wii itself, it sort of makes the NES/SNES controllers wired-wireless, preventing trip hazards.

Q: What do I need to do this project, and where can I find each item?

A: the obvious:

the rest:

Mayflash NES/SNES to Wii adapter – various online stores, ebay
NES and SNES controller – check your local used game stores. ebay has them, but be careful of knock-offs. Always look for Nintendo’s logo. The design patients for the controllers have expired, but knock-offs will never have Nintendo written on them.

Salvaged female NES 7pin controller plug

The ideal place to find one is if you have or know someone who has a dead/unwanted NES. Alternatively, check ebay for the part itself that someone has already removed or buy an NES for parts. Getting it out of the system is real easy – Simply remove the screws holding the case together, remove the RF shield and simply unplug one of the controller ports. Finally unscrew both screws on the black plastic piece that keeps the 7pin connectors in place.

small star screwdriver – your garage/junk drawer/hardware store.
soldering iron and solder – hardware store.
desoldering pump/braid – hardware store.
scissors – your kitchen/department store
glue – may not be needed, depending on your skill.
a sharp work knife – your kitchen/craft store.
small pair of pliers – garage/hardware store.

Okay! With that out of the way, let’s get going!

*Desclaimer: Following this tutorial should allow you to achieve desirable results, but that being said I take no responsibility for following my advice here. By continuing to read this you take full responsibility of damaging your hardware, burning or cutting yourself. Don’t be a jackass and you should be fine.

1. Take your Mayflash NES/SNES to Wii adapter apart by removing the four screws on the back. Set aside the top part of the shell along with the four small screws and the turbo fire button in a safe place, preferably in a bowl so you don’t lose anything.

2. Unhook the cord and remove the PCB from the bottom tray. Place bottom tray in bowl with the other side and the screws.

Top side of the Mayflash PCB

3. Carefully examine the PCB. You’ll notice that the Famiclone DB-9 plug is connected to the PCB using all nine pins, even though Famicom/NES controllers only use five pins. On the real hardware, the two extra pins to make of the 7pin connector were only used by specialty controllers such as the Zapper or PowerGlove. You will notice a pattern that looks like this:
1 \ o o o o o / 5
**\ o o o o /**
*6 `~~~~~’ 9*

Note that this diagram shows the correct pins that face away from the PCB. In other words, the pins that are normally visible and plug into DB-9 controllers.

4. Use a soldering iron and soldering pump/braid to heat and remove the solder that holds the DB- 9 pin plug. This is a slow process, be patient: Don’t try to forcefully remove the pins as that will most likely result in damaging the entire PCB.

Desolder the nine solder points on the left.

5. Once you have the old DB-9 pin adapter removed, either discard or keep for a future project. Either way, you’re done with the stock DB-9 pin connector for now.

6. Prepare your salvaged NES 7pin adapter. If you’re using one taken from an old NES, you can easily finish this project just by soldering the correctly colored wires. Wires may be different for third party NES female plugs, I’m not sure.

NES 7-pin connector pin numbers, the wire color and the job each does:

1 Brown Ground
2 White  5 Volts
3 Red     Clock
4 Purple Not Used on standard controllers.
5 Orange Latch/Strobe
6 Blue    Not Used on standard controllers.
7 Yellow Data

You will need only the brown, white, red, orange and yellow wires. clip the blue and purple right out of the way so you don’t get confused by them. In case you’re wondering, they’re for specialty controllers like the Zapper.

7. Back where the DB-9 pin adapter was, remove any excess solder and ensure you can place wires in each small hole. Here is the DB-9 standard layout for most Famiclone DB-9 connectors, including the Mayflash:

1 N/A
5 N/A
6 +5V
7 N/A
9 N/A

Reading the pins of a DB-9 is simple. The top row is 1-5 and the bottom is 6-9.

DB-9 pins you need to solder to are in represented by “x”. “o” shows pins that you can leave disconnected.

1 \  oxxxo  / 5
**\  xoxo /**
*6 `~~~~~’ 9*

Just to double check specifically, solder the NES wires to these places:

2 Yellow
3 Orange
4 Red
6 White
8 Brown

Here is a stripped SNES controller showing the location of the five needed pins. Note that the color of two wires on the SNES are reversed. Refer to what I wrote above.

8. Simply solder away. Take your time. Remember to solder on the underside only.

9. Before reassembly, try it out. Your oldschool NES controllers should now work perfectly on Wii games that support Classic Controllers.

10. Depending on where you want to place the NES 7pin connector, use your knife to cut away plastic in the way and possibly glue it in place. On my adapter I simply cut away enough plastic for the new NES connector to fit snugly in place and tightened up the screws to hold it in place. No plug, no mess.

My compeleted Mayflash adapter with a functional NES 7pin correction. Not the prettiest, but fully funtional and I used no glue at all.

11. Boot up your favorite NES, TurboGraphfx, Select Genesis Wiiware or Wii games including both Megaman 9 and 10 and enjoy them using either an authentic NES or SNES controller – that will still also work with the real NES and SNES!

Choose your controller of choice. Real NES or SNES controllers now both equally work great on thr Wii!

You can see the results of my work here:

Most NES controllers will work including third party Famiclone controllers as long as they adhere to the NES 7pin standard. Unfortunately, the NES Advantage arcade style stick doesn’t work correctly. One theory is that it needs 5v to run but the Wiimote can only provide 3v.

Any of these NES controllers will work on the Mayflash adapter. Sorry, the Advantage doesn’t work correctly.

Still, it’s a small annoyance compared to having a totally different plug.

Good luck and happy gaming!


14 Responses to “Mayflash Wii to NES fix tutorial”

  1. Great tutorial, anyone with a some skills can do it. Thanks

  2. i was wondering wil the nes controller read well with the homebrew channel nes games also .. wheni emulate them .. or only for the nes games u buy from the wii channel shop ? may sound like a dumb question lol

    • satoshimatrix Says:

      Yes, it works fine for all homebrew channel applications. All its doing is routing button commands from the Wiimote to the NES and SNES controllers in the same way that the Classic Controller does. This works with any game or program that supports the classic controller, which the NES emulator on the Wii does and VC games do as well.

  3. I am working on an NES-to-Famiclone controller adapter that one could daisychain onto the MayFlash one — this might be preferable for some who would rather not modify their MayFlash adapter. I have some pinouts posted for this and will post a video of the finished working product soon on my own blog.

    P.S. Some of your images no longer seem to work.

    • satoshimatrix Says:

      That’s one solution, and Mayflash themselves have responded to this very mod tutorial by now including their own Famiclone DB-9 to NES 7-pin adapter with all the new Mayflash NES/SNES adapters.

      I’ve fixed all the broken images and now you’ll be able to see what I did in detail. Thanks for your comment!

  4. I have only found a few of the nes/snes to wii’s online but not the 7pin adapter are these not available anymore?

  5. Thorsten Says:

    I tried it the way, you described, but now the A and B Button on the Controller are doing the same.
    I tried it with Mega Man, and on both buttons, he jumps. Half on the one Button and very high on the other Button.
    Do you got an idea, what the problem ist?
    By the way, Iam from germany, using old 7Pin-NES-controller-plugs.

    It would be great, if you got a hint for me.
    Thank you in advance,
    Snake Plissken

    • satoshimatrix Says:

      You probably have a bad connection, or are using a third party controller. Test it with as many controllers as you can – borrow them from friends, etc. If the problem is universal, get out a multimeter and double check all of your connections. You might have an incorrectly grounded or joined trace.

      • Thorsten Says:

        Sorry for the new posting below this one.
        I tried again, with the same result. No contacts are touching each other, I cannot find a mistake.
        I will try with a multimeter tomorrow.

        Snake Plissken

  6. Thorsten Says:

    Then it could only be a bad connection. But what could be the reason for it? I got 3 Original-Controllers, but only one is working, maybe 2 are defective.
    So I just can try to find someone else, who can help me to doublecheck the connections.

    • Thorsten Says:

      Okay, I give up. Iam not really good in using the Multimeter and I got not the real knowhow, to find out which opportunities I got now.
      Have to consider this “project” as a total fail.

      • satoshimatrix Says:

        Well, last resort you could always mail it it me and I’d see if I can fix it for ya. Or email me highly detailed pics. my email address is bradykachan at gmail dot com.

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