Could have been a [weakness] in the amp to start with but very telling that both your instances were after power outages. With that in mind and having had anything [like] an issue once. I’d be inclined (just me) to add more protection into the chain. I really don’t want to find out the hard way what will and will/not get through the wiring and am cognistant of the fact that certain particular pieces of electronics can be more suspectable than others.

Many (surge/storm) horror stories in my area. I started extensive research into the whole issue of electronics/wiring protection. Over the years the only electronics I had personally lost were a microwave and one LCD thermostat. (but I really started to think on the topic after dragging home more brandnew AV gear than I ever have all in one revamp!

During research (all theoretical mind you) I discovered that MOV based surge protection degrades. Hit after hit brown out after brown out, eventually its performance will not equal its original specs. I have seen arguments that it degrades the most after the first couple (hits) stabilizing after that point with extremely incremental small degradation noted when bench tested after its initial loss of protection level. I’ve also seen the argument that its very dramatic to watch MOV based surge protection melt down and catch fire at its failure point. I don’t’ know a single person this has occurred to personally.
But reading what I did find, - became interested in [Series Mode] surge protection. I’ve forgotten ½ what I learned but unlike MOV based it sends the surge through a different path to dissipate excess current. And can do it time after time {with no degradation} its joules protection rating is at the same level your whole house wiring will melt at anyway before a Series Mode will fail. In other words if a series mode fries you had a large enough direct hit to lose the whole house…nothing will protect you.

If all the above is true, Your panamax by having some hits has degraded to a degree (but no MOV based have gauges onboard to document the degree). . The only time the Panamax will bother your with an alert is at catastrophic failure of the entire unit.
Your cheapest way to deal with it, is get an electrician (if you own your own home) to put a whole house surge protector on your main panel.

My neighborhood is OLD, and very prone to some bizarre power ups/power downs. I live in a state with 35K plus towering storm systems. Eventually (when I get to it) I’ll own ever-conceivable protective device possible from my main panel forward.

Right now I too am running a Panamax, it was quick and covered my coaxial cable for the satellite also (something many consumers forget to protect) I will eventually add to the Panamax. My original idea was to daisy chain possible 2 additional “Brickwall” surge protectors either one at the wall before the panamax, or two after the panamax one for the amp/one for everything else in my AV. I need to research the effects of all these ‘filters’ before I decide the final config. I might skip all that and keep looking for series based main panel protection.. Last time (I had time to look) all the units I found for this duty were whole panel MOV based devices.

Very possible it was just a blowout waiting to happen on your amp. But since it appears it got through or was set off by power outs. It would worry me, not to increase my level of protection, as in all our electronic purchases some items are just more sensitive than others to power fluctuations.

(I need to send this to Gonk, Gonk if he had anything to say on any topic would say it all concisely in two sentences). Sorry no time for edits.!