cps2 capcom cabinet jamma question

[bulge2]

hi all

im currently converting a Xmen children of the atom cps2 cabinet to play MAME on my xbox.  The conversion is going well and is pretty much functional other than one problem. 

The Jamma connection on the cabinet are not the same as in the manual as the cps2 jamma i have in front of me has an extra voltage on it.  if you look in the images you will see on pin 5 there is a purple wire that is not in the manual.  i have followed the wire back to the power supply and it is a -5v cable.  Everything works well when connected to Xmen on cps2 but when disconnected from it the coin mech and speaker click repeatedly about twice a second.  When connected to my xbox through my conversion board the click is still present.



While testing voltages with multimeter i acciedentally crossed the -5v wire (purple on pin 5) and the +5v wire (orange on pin 6) and the clicking stopped.  When these connections are bridged the problem goes away, although im not happy this is the correct way and may lead to damage later on. 

I have disconnected the -5v cable and nothing changes.

Help!

[Crowquill]

The JAMMA specs include a pin for -5V. Many games however do not use this pin. Because of this, some JAMMA harnesses won't have the -5V wire connected or it'll be missing that pin altogher. My Atari Primal Rage cabinet is like that with the factory harness. This may also be the case with operators who converted old cabs to JAMMA.

Any generic cab built to use JAMMA should have the -5V wired in as it's part of the spec. Most of the CPS-2 games I've ever seen were in Dynamo cabinets that should be like this. Do you know what type of cab it is?

I can't help much with the popping sound. I'd think it be some sort of a grounding issue. What part of the coin door is popping? The only thing I can think of would be a counter maybe.

[madgammer]

Not trying to thread jack, but I have a primal rage cabinet and I will be converting it to a jamma shortly.  Would I end up with the same problem?

[Crowquill]

It might be a problem if you're playing games that require -5V. I only have a few boards and neither Mr. Driller 2 or Soul Edge use -5V, but there are plenty of JAMMA games that do. It's quite possible to add the missing pin. My cabinet had been converted to Tekken 3, and the operator had added pins for the start buttons as PR just uses button 1 to start. The part that confused me when I first got it was that the start button pins were still wired onto button 1 so that pressing it sent both signals. Adding these pins is really all you need to do to "convert" it as Primal Rage is technically a JAMMA game.

As the standard includes -5V, games that don't use it have either no metal contact or a contact that's not connected to any electronics. Capcom's CPS-2 is a good example of this.

If you want to compare notes on anything else, just send me a PM.

[Chris G]

Found this Bob Roberts article I bookmarked a while ago.  Perhaps there's some info in there that would be helpful...

http://homearcade.org/BBBB/jh.html

[madgammer]

It might be a problem if you're playing games that require -5V. I only have a few boards and neither Mr. Driller 2 or Soul Edge use -5V, but there are plenty of JAMMA games that do. It's quite possible to add the missing pin. My cabinet had been converted to Tekken 3, and the operator had added pins for the start buttons as PR just uses button 1 to start. The part that confused me when I first got it was that the start button pins were still wired onto button 1 so that pressing it sent both signals. Adding these pins is really all you need to do to "convert" it as Primal Rage is technically a JAMMA game.

As the standard includes -5V, games that don't use it have either no metal contact or a contact that's not connected to any electronics. Capcom's CPS-2 is a good example of this.

If you want to compare notes on anything else, just send me a PM.

Ahh the -5 volt.  Ok got it.  I think it should be pretty straight forward since the cabinet hasn't been touched.  Thanks for the tips.  I'll be picking up the cab shortly so until then I won't know for sure.

[bulge2]

i think its definately a grounding issue and i sure i can unplug it from the power supply and it will work.  in fact when i unplug the 12v/5v plug from the power supply it does stop but then so does the audio.

pictures of the cab:





i suppose its a case of unplugging wires till it stops

[Crowquill]

Are you actually using the JAMMA connector then? How are things interfaced?

I'm guessing you should be able to disconnect both the 12V and 5V since you're not actually powering a game PCB with it. It's generally considered a bad thing to run the power supply without any load on it. If there's a seperate sound amp in the cabinet, you should be able to run an external power supply for it.

I guess I'm just saying it'd help to know the setup a bit more.

[bulge2]

ok the power supply for the cab has two ports one for the monitor and one i have unplugged - for the audio and coin mech and lamp i guess.  here is  couple of piccies of the ouput




you can sort of see where the cable go from the jamma.

im going to disconnect some over the weekend and take some more pictures