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Main => Main Forum => Topic started by: gsoul on January 03, 2006, 08:14:36 pm

Title: Jpac / Jamma+ cabinet (Mortal Kombat)
Post by: gsoul on January 03, 2006, 08:14:36 pm
Okay, I've got a few questions regarding hooking up a J-Pac to a Jamma+ Mortal Kombat machine.

My machine has Mortal Kombat 1,2,3 & 4 in it. Awesome, but I still want to play some classic arcade goodness.

So I hook the J-pac into the jamma harness. The two sticks work along with the button 1 and the 1UP and 2UP buttons, as does the coin door. The remaining 5 on each side do not work.

So what I'm not sure on is the whole grounding thing etc.

So I figure that I add a wiring harness and solder it onto the existing wires (not the black ground) on the buttons, then wire the other end directly into the J-pac. What I'm unsure of is how to ground these buttons. They're already ground to the power supply in the cabinet, but I figure they need to be grounded to the J-pac.

I'm a complete n00b with electronics, so any light you guys/gals could shed would be appreciated.

Basically I dont want to intefere with the running of my super mk cabinet, so I remove the J-pac, plug in the UMK3 board and I'm off.

Somewhere in hooking this up before, I blew the chip on the j-pac, thanks heaps to Andy for sending me a new chip.

So now I figure I need some professional advice.

Ideas?
Title: Re: Jpac / Jamma+ cabinet (Mortal Kombat)
Post by: gsoul on January 04, 2006, 04:14:16 pm
C'mon, don't you guys know what I'm talking about? Am I on drugs? Whats going on here?

Someone help me out please!
Title: Re: Jpac / Jamma+ cabinet (Mortal Kombat)
Post by: markrvp on January 04, 2006, 04:54:26 pm
I do not have a J-pac, but from looking at the picture below, you should connect the button ground loop to the screw terminal marked:
Title: Re: Jpac / Jamma+ cabinet (Mortal Kombat)
Post by: gsoul on January 04, 2006, 05:00:59 pm
So the buttons arent already grounded to the power supply of the arcade machine?
Title: Re: Jpac / Jamma+ cabinet (Mortal Kombat)
Post by: markrvp on January 04, 2006, 05:27:52 pm
Don't you have a separate power supply for the computer connected to the Jpac?

In either case, I would try grounding buttons 4-8 for both players to the GND on the Jpac and see if that works.