The high temps had me really worried.

I took it apart, cleaned the chip and heatsink, and reapplied thermal paste.

Made all the difference in the world, with the temperatures.

When I removed the heatsink, the paste was a little thick in some areas and absent on 30% of the chip, I'd say.

It lasted fine for years, but, I guess that catches up with you.

Thanks so much for all your help! It's helpful just to have a second person providing feedback.