In the middle of a print my PSU started crackling, popping, sparking and giving off smoke. Any ideas what might cause that? It has printed for hours, running an Azteeg X3. It is a 12v 30A switching supply, and has a fan and LED strip connected to the same terminal block on the board.
I don't see any obvious shorts, at least not between the wires on the screw terminals

I don't see any obvious shorts, at least not between the wires on the screw terminals