Hey guys. I know there are a lot of us here that use/need the Jamma extension harnesses and from what I can tell, they are all the same. I have purchased a few from all different suppliers and I always get the same ones. There are a few issues with them. They will not work for most games right out of the box because there is no video ground on pin 15 of the component side of the connector as well as the 5v, 12v, and grounds missing from the same side....
So you have to solder a wire onto the ground wire at pin 28 of the solder side and jumper it over to pin 15 of the component side to provide a ground for the video as well as jumpering the 5, 12, -5, and grounds from the solder side over to the component side because they are only on the solder side of the connector...
Solder side...
Component side...
There's also no -5v. If you are going to use this extension harness for any of the 90's Midway fighters or any game that needs the -5v, you have to install a jumper from the Jamma connector to the edge connector at the appropriate locations...
Hope that makes sense because if you don't do thee mods, your board MIGHT work, but your colors will be wrong because of the missing video ground and your audio might not work because of the missing -5v. Let me know if you have any other questions and opinions are appreciated!
Thanks!

So you have to solder a wire onto the ground wire at pin 28 of the solder side and jumper it over to pin 15 of the component side to provide a ground for the video as well as jumpering the 5, 12, -5, and grounds from the solder side over to the component side because they are only on the solder side of the connector...
Solder side...
Component side...
There's also no -5v. If you are going to use this extension harness for any of the 90's Midway fighters or any game that needs the -5v, you have to install a jumper from the Jamma connector to the edge connector at the appropriate locations...
Hope that makes sense because if you don't do thee mods, your board MIGHT work, but your colors will be wrong because of the missing video ground and your audio might not work because of the missing -5v. Let me know if you have any other questions and opinions are appreciated!
Thanks!


