Turn the board over to visualize the component part side.

Whenever one works on a power supply one must remember not to touch the components since the capacitors may still be charged and could cause fatal electrical shocks. Discharge the capacitors before working on the board.

There is a reason for all that goop. That is the MOSFET that appears to be the Achilles Heal of the power board.

That is a KF12N60 N CHANNEL MOS FIELD EFFECT TRANSISTOR.