The heatsink has no fan, an interesting kind of heatsink that is supposed to be wonderful, but I don't think it's working so well with my setup, maybe that's the issue... I'll try a different PSU next, and if that's not the problem, I'm going to be replacing that heatsink with another.

I cleaned out the PSU, still nothing.

As for the motherboard bending, unfortunately it is possible, but how could I test that? It was nothing significant, but I am slightly worried because of how fragile things like this can be.

Thank you nihil for your insight.