JAMMA button config question SOLVED!

I just picked up an Xmen vs. Steet Fighter 25' cabinet for $300. Very happy with the purchase, but when I hooked it up to G-Darius which is a standad JAMMA game, none of the buttons work except the start buttons. Now all the buttons work with G-Darius in my Neo Geo. But of course due to sterio reasons, I don't want to use it that.

So what's the problem. I wouldn't think it has anything to do with the kick harness since that merely ADDS three buttons. I thought CPS-2 was standard JAMMA apart from the kick harness? Any suggestions?

Thanks

Maybe all the buttons are grounded to the kick harness apart from start?

Make sure that the first 3 buttons are all grounded to the JAMMA harness and not to the CPS-2 kick harness.

I checked. On both sides, the bottom three buttons are connected to the kick harness. But the top three buttons are connected to the JAMMA harness, which should be the ones the G-Darius uses.

Did you check the button lines, or did you check the ground? The button lines are going to go to jamma, but there is a ground coming from the kick harness, and a ground coming from the jamma connector. If they got lazy and ran all of the grounds through the kick harness, that the buttons wont work.

Here's an easy multimeter test. The ground for the main 6 buttons should be easy to find, since its a wire that hops to each one of the buttons to the next. Put one end of the multimeter probe there, on the ground for one of the punch buttons. Set the multimeter to resistance (ohms), and with the other probe not touching anything, it should show infinite resistance. Touch the other probe to the ground wire on one of the other punch buttons. It should show close to 0 resistance. That shows its connected. Now, take the second probe, and touch it to the ground wire on the start button. If it shows infinite resistance, then the ground from the start goes to the jamma harness, while the ground for the buttons goes to the kick harness. Since the kick harness isnt used by your shmup, it never gets connected to ground, and the buttons never appear pressed.

Easy fix? connect up the ground wires from the buttons to the ground used by start. then everything will use both the kick harness and jamma harness grounds (which are the same thing on a cps2)

Thanks Toodles, I think you solved my problem. I don'thave a multimeter, but I traced the grounds (grounds are the wire that's usually blak, right?) to the back of the cabinet, and sure enough they seem to go into the kick harness.

Now I haven't really don't much with arcade machines so I'm afriad I know close to squat about rewiring them, but what you said about continuing the ground from the star buttons makes sense. I found where the ground ends on the last start button, but I don't know how to continue it. I would imagine it involves pulling of the connector (forgive me, I don't know what they're called) and inserting a second wire and then putting a new connector over both wires.

Well, I mihgt be able to figure that out by trial and error, but where should I go for parts (wire, connectors and such). I imagine there's a good online store where I could order some?

Thanks again

Mad Mage said:

Thanks Toodles, I think you solved my problem. I don'thave a multimeter, but I traced the grounds (grounds are the wire that's usually blak, right?) to the back of the cabinet, and sure enough they seem to go into the kick harness.

Now I haven't really don't much with arcade machines so I'm afriad I know close to squat about rewiring them, but what you said about continuing the ground from the star buttons makes sense. I found where the ground ends on the last start button, but I don't know how to continue it. I would imagine it involves pulling of the connector (forgive me, I don't know what they're called) and inserting a second wire and then putting a new connector over both wires.

Well, I mihgt be able to figure that out by trial and error, but where should I go for parts (wire, connectors and such). I imagine there's a good online store where I could order some?

Thanks again

Click to expand...

Run a wire from one of your JAMMA ground pins (the last two pins on both top and bottom are ground), to the ground on one of the switches on the 1P side (doesn't matter which one, as long as it's one of the ones are not responding). Then loop that to the 2P side as well. It'll look butt-ugly, but it'll work.

Why not just splice it from the start button like Toodles suggested?

Oh, I think I can get the parts I need from my local electronics store.

dont forget to check the ground from the sticks, too.

Removing the quick disconnect from one end of the main button's ground chain, and the ground from start, and re-crimping them with new quick disconnects and an additional wire connecting them would be the proper way of doing things. If you just want to play and don't mind getting ghetto, strip some of the wire insulation off from the middle of the wires, twist and electrical tape a wire to connect them. But new quick disconnect terminals is the proper way of doing it, and more reliable over the long term.

The terminals you need will be 0.187" wide if you are using american parts, and 0.110" wide if using asian style parts. It sounds like all you need is wire (18-24 guage, stranded), the terminals, and a cheap crimp tool. You should blow the extra $20 on a multimeter from radio shack though. You'll need it.

Thanks again! I went to my local electronics store and picked up the terminals and wire. They didn't have a cheap multilmeter, so I'll keep an eye out for one in the future (your right, it would come in handy).

I went back home and re-grounded the buttons from the start button. I did a pretty lousy job, but at least everything works!

If you want a cheap digital multimeter, I picked mine up at Frys for like 10 bucks.
Worth checking out, if there's one near you. (The ones at the Shack of Radio are too expensive!)

Next time I'm in the area I'll check it out. They didn't have one for under $40 at the electronics store I went to.