I have a 1966 Williams Hot Line machine. The basic premise of the game is to roll the ball over a matrix of plastic tabs in the center of the playing field. They are lit up to form the letters, H, O, T, L, I, N, E. Each time you complete a letter pattern a row of lights specific to the letters advances and you’re awarded 300 points. After you complete all of the letters, it knocks for a replay.
My problem is that whenever it advances a letter, it often advances several times, sometimes forever. It happens when those tabs complete a letter, as well as when a roll over lane at the bottom of the field advances it, and when the game is reset.
Looking inside… When I manually just close the advance relay it also happens. In fact when it happens the advance remains closed – otherwise it closes for the 300 points and opens. When I manually run the score motor – it’s used to count that 300 point award – the motor runs its cycle and stops reliably.
Where to look next?