View Full Version : J-PAC Start button issues

1st June 2006, 12:00 PM
I wanted to run mame through my arcade cabinet and I had a game logic board, xmen vs street fighter running in it. When I hooked up the J-PAC I noticed that the power supply didn't work but after reading http://www.ultimarc.com/jpac2.html in the JAMMA Cabinet Preparation it says, 'With no game logic board to provide a load, most cabinet power supplies would not work anyway'. So I didn't think much of it, but player 1 and 2 buttons seemed to be stuck on so after unplugging the J-PAC and plugging my game logic board back in the power supply still doesn't work. Would the J-PAC have somehow killed my power supply or is this mere coincdence?
After testing a few wires I tried unplugging the credit board and now the Player 1 and 2 buttons work perfect. Why would the credit board be doing this?
It's a leisure and allied machine with an NRI coin mech. It has 2 7segment LEDs that used to light up. The start buttons are retangular and have lights.
I think but could be wrong, if I replace the power supply the credit board will get it's power and release it's short on the start buttons. But I worry that the power supply will bite the dirt again!

Pics similar to my machine for an idea of what mine looks like but not my pics.

1st June 2006, 06:53 PM
I don't know if this will help but since noone else has answered I will give it a shot

The j-pac doesn't like 12v supply and can damage it..most coin counters and newer coin mechs require 12volts. It sounds like you are still getting these voltages if these things are working. I always disconnect the cabinet power supply if using a j-pac to avoid 12v running into it. The keypoard input produces the 5v needed so the cabinet power supply is not needed.
With my MKII cab which is original I just disconnect the power supply from the stepdown to the inverter( which produces the 5v and 12v for the cabinet ). Simply plug it back in when I want to play the original PCB.
Hope this helps
Just keep the 12v out of it if your using a j-pac..If you need 12v run it from your pc

2nd June 2006, 11:36 AM
Unfortunitly these things aren't working. The credit LEDs and the coin mech I think need the power and I want it to work with the j-pac and the game logic board.

The 7segment LEDs are under the marquee and say how many credit's you have.
Is it possible to wire up the service switch, I noticed it's not wired up on the J-PAC but it would have been nice.
Can anyone tell me where I can find the wiring diagram to the box with the coin counter in it so I can work out where all the wires are going.

Replaced the power supply and everything works now. As I thought it needed power.