And the end of the electrolytic cap looks okay? (The blue can). If that thing spit out over all the parts, maybe it can explain the mess.

Otherwise, it feels like something is heating up in an undesired way. This could be something downstream of some filtering capacitor that is now dead?

If you had a thermal camera, it would tell you a lot, but not necessarily point at the bad part. Can you get more run time with a fan? (Not a permanent solution)