Stephen,
In conventional mode, I think DC voltage triggers the bell. I'm not sure, but this is what I recall. So, if you have DC voltage on the track, it seems like something might be wrong inside the ZW. However, since you can still program the ZW, it appears the logic chip is working. I recall GGG saying something about a damaged MOS-FET putting out DC voltage. Either way, I would try to get GGG or Gunrunnerjohn to work on the unit. It may be a simple electronic component to replace on the board.
George
