Cant press "A" on my cab. Brings up test screen and or inserts credits

I bought a converter from jammaboards.com to hook up my 2 slot board to my jamma wired cabinet. When I use this adaptor when using my 2 slot board this would either insert a credit, or if in homecart mode, pause the game. So I unhooked the credit LED's and everything works fine. SO now if I piggyback this adaptor, with the adaptor to play jamma boards on a neo geo multislot cab I get a test menu when I hit the "A" button. WTF is going on? I know it has something to do with the neo adaptor re-routing the wiring to make "A" the select button. How do I fix this for good? The whole problem here is that I can't play JAMMA boards on my JAMMA wired cabinet cause it is wired for neo geo single slot JAMMA. which basically means jamma with a seperate 4 pin molex adaptor for sound that plugs into the original MV1 Neo board. Can someone please explain to me how to wire my cabinet so I can get sound without using the stereo cable? And tell me if it is possible to still keep my stereo cable and have the option to use it or not. Cause I dont care if I have stereo with jamma boards. But I would like to with my neo geo games. Someone please let me call them, or just explain to me in detail, or anything. I'm so frustrated. I just want to play games with sound.