Back around Christmas my LG oven (model LRE3083ST) started smelling like burning plastic when preheating. Removing the rear cover revealed a partially melted relay and spade terminal (see attached). In spite of the smell, everything was fully functional.

I replaced the PCB board, part #EBR74164805 (also attached). I also replaced the melted spade connector on the red wire. Upon reassembly, everything seemed fine. No more smell, and all functions were normal.

A few days ago, three months after replacing the PCB, the smell has returned. I pulled the rear cover off today and the same terminal on the same relay is once again melted, exactly as before. Also as before, everything about the appliance functions normally.

I'll be replacing the PCB again, but what else should I be looking for at this point? Is this thing a fire waiting to happen?