Take the leads to the Marx off the the Z and check again. If it trips the breaker you have track power issues. But before you leap, IMO, the correct chase scenario here is process of elimination, so disconnecting the track and trying again with no load at all checks the transformer out. Add the Marx back in to confirm its operation. Then check you are using the correct polarity to trigger it (ie a hot actuator isn't near or touching a common on the track, more a tubular thing, but.....)
