Ironwood 885, Char-Griller Flat Iron Premium griddle, InkBird Sous Vide
I cannot tell from the photo whether the residue comes from the transformer arcing or from a blown capacitor next to it. Either way, the controller is probably dead. If you know a good electronic repair shop, they may be able to replace the defective parts. However, what you do not know is whether the failure also damaged other parts of the board such as processor chips. Thus, replacing the board is probably the best idea.
I had issues with our original unit erroring out from time to time because it would let the pellets lose flame and then kill the fire while still slowly adding more and more pellets to the pot. Then purchased a new control board from the YAOAWE. Haven't had that happen yet with the new control panel. Works as well as the original..