Quoted from Mikec2003:Well, i never thought to check the coin relay since the machine has the coin mech bypassed. Its set up to where i plug it in and press a button that turns it on and acts as a game start button. But now that button just turns the machines lights on, the score doesnt reset to zero, nor does the machine reset at all.
Did you confirm that nothing happened with the "free play" setting... That is, is the switch on the credit reel still bypassed to add the credit when the start button is pressed? If that switch opened up, it would not start a game and behave as you described.