The top drop target bank has a small coil for each target that drops each corresponding letter "METEOR". I just want to rule out the fact that at the end of each ball, the target bank resets and then drops the targets that were dropped on the previous ball. If you play a 4 player game, the dropped targets are remembered for each player. This may seem like random drops, but they are not.
I rebuilt the drop target assemblies on my Meteor during the restore. Maybe consider this for the next step if the problem is not related to the above ?