AdjeIf you are running Windows, try checking the Event Viewer whenever something malfunctions. I had an issue with my USB ports where they would randomly lose power despite being plugged in and managed to fix it (for now) by re-enabling C-states and slightly downclocking my CPU, since it was telling me it was power related. If it shuts down your PC or forces you to restart, look for events with the ID 1074, 6006 and 6008.
It's not a malfunction in the traditional sense of windows detecting that it stops working, but more so the data itself is corrupted, and windows doesn't even notice. Although funny that you mention c states, I did disable them the day of the event for an unrelated reason.
wolsneI experienced this exact same issue under the same circumstances in 2014, replacing the motherboard only was sufficient to correct the problem. Never was able to find any empirical evidence that it was caused by the surge, but nonetheless everything else was operating seemingly fine.
I'll get a new one today ty