I had a similar potential major issue several years ago in a campground with multiple extreme voltage spikes. The voltage was spiking to almost 200 volts and the EMS saved the camper from damage. I called the Progressive Industries folks and told them of the issue and that the EMS was seven years old. They still sent me two new circuit boards at no cost. I’d give them a call and get new replacement boards. After an event like you experienced, I wouldn’t take any chances using the old boards even if the system seems to be working properly. I had to end up requesting several new boards because the Progressive Industries folks kept sending the boards in just a little bubble wrap and in an envelope. Several arrived crushed or otherwise broken. I explained to the contact person that they really should be sending the boards out in boxes but they didn’t seem to care. Anyway, I ended up with two new working boards.