Alors apres une recherche, il semblerait que le 56 pins connector de la carte MVS 4 slots soit different du 56 pins classique jamma. Ceci est tire du site que tu mets en lien (et ceci explique pourquoi cela marche avec mon 1 slot)
Q: Will the motherboards work in a JAMMA cabinet?
A: They will all work, but are not 100% JAMMA compliant
Q: What does that mean?
A: The 1 slot boards are the closest to JAMMA, but have the addition of a 4th button. Some of the 1 slot boards have an external connector to run Stereo sound instead of the mono JAMMA sound.
Q: What about the other boards?
A: The 2, 4, and 6 slot boards are wired to what I would call the MVS standard. It is almost the same as JAMMA, but have the additional 4th button, a select button, and Stereo sound out of the harness instead of an external connector. The test switch is also in a different location than the JAMMA test switch.
Alors comment faire, et bien le site donne aussi la reponse avec un jamma adaptater
http://www.hardmvs.com/html/jammaAdapt.htm
Le mieux c'est peut etre de peut etre d'en acheter un sur un site d'arcade ou de mettre un post dans le forum achat pour en achter un.