8/30/2018 7:08 AM
My first thought was a transformer issue, but the chances of that happening in all 3 clocks is miniscule unless there was some type of short or power issue that damaged them. I would go to the first bad clock supplied by that power and double check voltage. Check hot to common, hot to ground, common to ground, common to earth ground, hot to earth ground and ground to earth ground. You should see very little variation on voltage on the hot, zero to little on common and none on the ground. If you have a generator or other 120v power source you could make a pigtail connector and try each clock individually to check for proper operation. Hopefully this can wittle it down some.