Solder a second ground to either of the points marked only "ground". Not sure about that z80 ground point, so probably best to avoid that one for the ground. Note that adding a second wire soldered to either of the ground pads could increase stress on the pad, so probably good to encase it with some hot glue.
Follow the wires already soldered to the 4th button connections, and see where they go at the JAMMA harness. I'm guessing they go to the points that are used for p1 and p2 button 4 in a neo geo setup. If that's the case, they are unassigned on standard JAMMA boards, so just add a second wire to those solders, with the same advice of encasing with some hot glue.
If you find the button 4 wires go somewhere else, please provide your findings.
Thanks for the help, so can I have two wires on one solder point for the ground wire?
And also would I need to remove the yellow wire 4 button from the fingerboard and jamma harness end and replace the wire with the one on the kick harness?
As for ground, yes it is common, so it doesn't matter where on the ground path you land the ground from the kick harness. For a test and your own understanding, you can take a multimeter and set it to test continuity. Connect a JAMMA board to the JAMMA connector. If you touch one probe to any point labeled as a ground, and the other probe at any other point labeled as ground, they will ring out as being continuous. So, test at the board side of any of the ground pins, and probe at any of the ground pins on that fingerboard you will be soldering to, and it will be continuous (or connected). Keep one probe at one of the test locations, and move the other probe to other points labeled ground, and you will see they are all continuous or connected.
This may not be true for that "z80 ground", and will also likely not be true for video ground. Those are unique, so stay away from them for your purposes.
In that same vein, you could splice the kick harness ground to any ground wire, if you would prefer not to solder it to the factory fingerboard.
As for the yellow wire, again, check to see where it's coming from/going to. If it's going to the pin on the JAMMA harness that is assigned to "button 4" for a neo geo pinout, that pin is unassigned on standard JAMMA boards. But, you could connect the harness up to a JAMMA (non Neo Geo) board, look at where the contact for that pin marries up with the JAMMA board, and see if there is a line coming from that contact, going to somewhere on the board. If the contact is not unassigned, or you find that the 4p wiring at the fingerboard is going somewhere else in the cab or to some pin on the JAMMA harness that could cause unintended consequences when pressing button 4, then you probably want to desolder it before soldering on the wire from the kick harness.
So, you have to look at the yellow wire and figure out: does it go to the JAMMA harness, or does it go to somewhere else? If it goes to the pin assigned to neo geo button 4, then you should be fine just adding the kick harness wire. If it goes somewhere else, then probably best to desolder and replace with the kick harness wire.
Hope that all makes sense, and provides a little bit of insight.
Awesome, Thanks for all your help. I will check out the 4 button wire, I have my supergun hooked up to a CPS2 board. So if I find that the wire is assigned I can add add the 4p wire from the kick harness on to it?
tony starks wrote:Awesome, Thanks for all your help. I will check out the 4 button wire, I have my supergun hooked up to a CPS2 board. So if I find that the wire is assigned I can add add the 4p wire from the kick harness on to it?
Figure out where it's going to and coming from, and post what you find. Can further determine what needs to happen from there.
