Today, a thunderstorm passing overhead just killed, or better grilled, my ADSB receiver. There was no direct lightning strike but for some reason the DC-DC converter on the PoE hat stopped working and shows a short on the 48V input. The Raspberry Pi and everything else on the 5V side is working just fine. The PoE hat is powered by a 48V switching supply off the 220V mains. That is also still working fine, probably because of its output short circuit protection.
On the PoE hat the DC-DC converter is a Silvertel AG9805-M, ordered some new from http://www.semiconductorstore.com. $8/piece is a good deal compared to the price for the PoE hat or replacement converters supplied by other manufacturers.
I will stock some spares just in case that happens again. But then I need to investigate why that thing breaks.