Wouldn't that be a reason to be worried about a damaged CPU? My fans start to spin, and then quit...

As for the spacers, yes, I'm not that dumb, I even took the motherboard out of the case and set it on cardboard and tried booting like that, to no avail, same exact problem as when it was in the case.

I really doubt it's the power supply, as it worked fine right up until I switched cases, and it turns out I don't even have an extra to test it out with.

Any other possibilities here?