If this feed is all in conduit (you stated PVC), why not pull it out (attach a pull rope first) and inspect the wires (yes all 200')? Then you can fix the conduit and replace the damaged wire. It must be a bad wire if you have the correct voltage at the source but not at the barn. I had one very similar to this on an overhead feed to a barn were the SE cable noodle had corroded to the point that it had only three strand that were intact.
