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Main => Main Forum => Topic started by: TGov on May 04, 2013, 04:52:16 pm

Title: JPAC, what I am doing wrong??!?
Post by: TGov on May 04, 2013, 04:52:16 pm

I have two different JPACs that I am struggling to get working properly.  My problems relate to the controls.  The video sync part on both of them are working just fine.  I know one of the JPACs worked perfectly in my Dynamo cab that was wired for JAMMA when I got it.  The inputs and everything worked just fine. 

Fast forward to now and I have my Donkey Kong build that I wired up for JAMMA myself and a friends cabinet that I also wired up for JAMMA.  I can not get the button inputs to work on either of these.  The keyboard passthrough works just fine, but I get no input from the JAMMA harness OR the extra button ports. 

I have the same exact problem on both cabs, which I wired.  I can only assume I have something wired wrong on the JAMMA harness to work correctly for the JPAC.  I can plug a JAMMA PCB into the JAMMA harness and the buttons work just fine on both cabs, plug in the JPAC and I get nothing.  I have checked my grounds and they all check out.  The only thing I can think is that I need to ground the JAMMA harness to the cab in a certain way other than I have it now.  It is driving me nuts.  I would assume the JPACS are both bad in some way but one of them works fine on my other DYNAMO cab that I did not wire.

Any ideas?

Title: Re: JPAC, what I am doing wrong??!?
Post by: BobA on May 04, 2013, 05:35:38 pm

Are you using an arcade power supply?   If so where did you wire the ground wire on the jamma harness and is it the same ground as the power uses. The ground should go to one of the 2 ground terminals between -5V and +5v.  Do not use the FG or frame ground.  It is the 3rd wire ground for the AC in.

Title: Re: JPAC, what I am doing wrong??!?
Post by: TGov on May 04, 2013, 08:52:37 pm

I thought I did what you are saying, but I will double check all of it.

So, which one of the pinouts should be running to the ground you specified?

(http://www.blogcdn.com/www.engadget.com/media/2006/11/jamma_pinout_engadget_howto.jpg)

Title: Re: JPAC, what I am doing wrong??!?
Post by: BobA on May 05, 2013, 06:26:05 pm

Any of the grouped grounds on the jamma harness at one end or the other.  They should all have continuity if checked with an ohm meter.

Title: Re: JPAC, what I am doing wrong??!?
Post by: TGov on May 13, 2013, 10:29:53 am

Finally got it figured out.  Had to run the "check for new devices" in windows several times until the inputs started working.  I had to do this on both the xp and windows 7machine.   Works fine now.

Title: Re: JPAC, what I am doing wrong??!?
Post by: sandheaver on May 13, 2013, 03:11:06 pm

Glad you figured it out.  I find it interesting because the J-Pac is an HID device; it shouldn't require manual intervention at all.  It should appear as a human interface device without any intervention.

Title: Re: JPAC, what I am doing wrong??!?
Post by: TGov on May 13, 2013, 03:12:14 pm

I agree, but it worked on two machines, so something is up.