I have Truck Stop. It is my first machine. I love it. I have fixed a lot on it and it has been working nice. All of a sudden I started to have problems with the sound. The main music routine shuts off right in the middle of playing. All other sounds remain working. The music will stay off until a new ball is entered. Even if one ball gets locked and another gets released to the plunger (the music starts again). There is another different music routine that plays when green "release" lamp is lit. That routine works fine even when the other main music routine is off (without release of a new ball).

Anybody have any suggestions on where to start looking? The machine is in a vacation home so it does not get played much. The last time i was there I replaced a few lamp transistors on the main control board. The machine played well then. Other than that there has been no other changes. But now I am here again (a few months later) and now the sound is acting up. It was happening only occasionally but now it happens really quick and everytime when playing.