My Anet A8 power supply blew up
It looks like it passed final test but then the excess lead length was sufficient to be bent over in transit to short out the gate or base to the wrong voltage and result in a short circuit to everything in its path towards the fuse. Just replace the burnt parts and hope for the best or do an inspection that the factory forgot to do with a QC stamp, ( next time).

the solder blob can help with surge power sink on startup, but it was the bent pin that was the culprit.

A solder sucker or lots of braid wire can soak up the solder with sufficient heat from 75W or more to allow cleaning the holes after cutting off the part and removing the pins with tweezers while molten. Don’t get too hot to burn the board.