DB15 / Neo Geo Wiring Help

[edd_jedi]

I am trying to build a "fight stick" for my Supergun, and want to use a DB15 connector as the Supergun has DB15 ports, and also it will then work with my Neo Geo AES too. I bought this 15 wire replacement DB15 cable from Ali Express. I have managed to figure out what all of the wires are by grounding them, except I have one oddity - I cannot get P1 start to work on either the AES or Supergun.

In the player 2 port of both my Supergun and AES, grounding the pink wire activtes P2 start. All other direction and action buttons and select wires are identical in either P1 or P2 ports as per the table below. But I cannot get P1 start to work on either system. To check I'm not going mad I plugged in my regular unmolested AES stick, and P1 start works fine on both so it's not a faulty port. And it can't be a broken pink wire, as it works as P2 start.

I can't find a wiring diagram for this cable, but this is what I've figured out so far:

Brown	Ground
Yellow	Up
Red	F (Supergun)
Dark Purple	Down
Dark Green	B
Light Blue	A
Dark Yellow	D
Black	G (Supergun)
Dark Blue	Right
Light Purple	Left
Orange	Select
Light Green	C
Grey	?
White	?
Pink	Start (P2 only)

Grey and white don't seem to do anything, I know on DB15 several wires are for 5V so maybe it's those, but not sure what they do (if anything.)

Any ideas on why I can't get P1 start to work please?

 

[edd_jedi]

I opened up my AES stick to see if looking at that wiring helped, the colours are all completely different so not at all helpful! But I did notice something strange - button D has two wires connected (orange and green) and both black and brown are connected to ground. Looks like there might be two ground wires I need to connect together? Although strange that everything except 1P start seems to work with just one ground...

 

[BroadwayJose]

This should be it - disregard button 5 & 6 for Neo Geo purposes:

As long as you can identify and tie each lead in the cable to a pin on the header you should be good to go with this pinout.

 

[edd_jedi]

Through trial and error I have figured out that red is ground for Neo Geo, and brown is ground for the Supergun, they are not interchangeable for some reason! I can't explain this, but as above my original AES stick has two wires from the cable connected to ground (black and brown) so I'll try connecting red and brown together as a double ground and see if that works

 

[edd_jedi]

Turned out the grounding issue was a red herring, what was actually occurring was the connector was not connecting to the controller ports correctly. As with OEM Neo Geo controllers the connector is quite long, but in this case a bit too long so requires pushing in hard to make a good connection. I might shave a couple of mm off with a dremel at some point, but for now it's working.



So here's the correct wire colours for anyone else who buys one of those Ali Express Neo Geo replacement cables, as they're not supplied with a diagram and I had no luck finding one.

Brown	Ground
Yellow	Up
Red	F
Dark Purple	Down
Dark Green	B
Light Blue	A
Dark Yellow	D
Black	G
Dark Blue	Right
Light Purple	Left
Orange	Select
Light Green	C
Grey	Unused
White	Unused
Pink	Start