I have a network set up as follows -

1. BE550 is being fed by my providers box on the side of my home. Fiber optic to this device, CAT6 to the BE550 in a run of about 25'.

2. AXE75 is connected to the BE550 with CAT6 about 25 feet away in my office.

3. This AXE75 is feeding 3 remote routers. 2 are Archer A7 and one is another AXE75. All are connected via CAT6 cable routed to 3 separate log cabins. These cables are routed (partially underground) through 3/4" plastic electrical conduit. The distance to the A7 remote routers averages around 150'. The distance to the AXE75 is about 200'.

4. The AXE75 (call it the Party Barn Router) is a new install as of a week ago. It replaced another A7 that had been working flawlessly for well over 2 years.

5. That A7 (now the AXE75) feeds another A7 (again CAT6 and underground conduit) in another cabin about 75' away.

Weekend before last we were out of town when a heavy rain storm hit with lightning strikes. I noticed on my Teather app that the entire network was down. When I got back, the mother BE550 was dead. The port from the provider was live (I hooked a laptop via a cable to the port). I reset the BE550 and it came back to life but would not recognize the ethernet feed. I replaced it with a spare BE550 and got it active. 

I then got to existing Archer C4000 feeding the cabins (now the AXE75) and it was bricked. The replacement AXE75 woke up the A7's in the cabins and the Party Barn. The Party Barn A7 would not accept the ethernet feed. I then replaced it with the AXE75. This new in the box AXE75 power light would flash repeatedly. would see the ethernet cable either. I rang out the cable with my Data Shark and it rang "good". 

I quit for the day. 

When I went back to the Part Barn the next day, the new AXE75 was green lit across the board. I have no idea WTF happened but I had other fish to fry so accepted one less problem. 

We had to go to Nashville on Sunday and all was still well. We got back on Monday around 2 PM. We had just missed a gully washer. The rain tore up my road AND (wait for this) the AXE75 in the Party Barn hunting but was not finding the ethernet. Everything else on the network was working. I hooked up an old NetGear router - same thing - no ethernet.

I then hooked up the laptop to the cable and got right on the web. 

I am self taught on this stuff and have been able to figure out most of this stuff for the past 15 years or so. I now am out of my depth. All of my devices are set for dynamic IP and have up to date firmware. Power supplies are what came with the devices.

Does anyone see anything I am overlooking? Suggestions or observations are welcome.