I have a 1977 Bally black jack it will boot up. (have the 7 flashes on the MPU board) all the light are working and the chimes also but it will not play when I push the play button(credit button) I have 40 credits and it will not start a game. did the self test and all is good solenoid are freeing and the flippers work but the game will not start.????? when I push the (credits button) play button??????