i've just had a word with ultimarc. they said that i should check the voltage on the two coin inputs on the jamma connector. they said that it needs to be no higher than 5volts.
Why would the coin inputs need voltage at all!. It's just a switch, no?
Just like a standard button. The input (coin input) is ogically held high by the gameboard, then temporarily grounded to go low and tell the board a coin was entered. This should be the same with anything plugged into a JAMMA harness.
Am I missing somthing here?