I've upgraded my OS (Ubuntu 19.04) and my HDD to a SSD (1TB) .. and lately (after a few weeks after the upgrades) I've been bombarded with thermal shutdowns .. I've cleaned the fan, the duct, applied new thermal paste to the CPU and cleaned the MOBO .. everything is fine. The fan I have set to always on from the BIOS .. I've taken out the second HDD (DVD drive caddy), removed the battery and all USB devices and it still persists .. also, my warranty has been up .. any help would be nice! Oh, since I'm running Ubuntu, I don't have any "power management" options .. also, the temperature doesn't go above 75°F (so says the sensor) ..
Edit* I think I've found the problem, the fan isn't turning on anymore ..