If u know electronics, and have a few bucks to spend, u could put a NTC or PTC on all the MOSFETs, main diodes, or any where useful, and set up circuits or programs to act on that info. There are many many things observed and compared in electronic circuits. So they all have numbers with them.
Normally the big ATX SMPS makers, put a negative-temperature-coefficient sensor on the secondary side heatsink. The secondary-side rectifier diodes are on that heatsink. That NTC hooks into op-amp circuits, like LM393 comparators or LM358 op-amps. And they use RLC circuits to get certain things happen, at certain frequencies.
U can roughly get the internal temp of most parts if u know the surface temp, I should really learn some equations for this.
Last edited by Kaltenbrunner; 01-16-2019 at 02:51 PM.