Todd takes a look at a blown HVAC control board. His sister’s HVAC stopped working and Todd being the nice guy he is decided to have a look to see if it can be fixed. Turns out the control board is controlled by a PIC microcontroller, there was also a blown darlington transistor DIP package. After replacing the transistor package it was determined that the PIC was also defective. At this point there is not much you can do other than replace the entire board since the code on the microcontroller is probably read protected, might have been worthwhile having a quick look to see if the code was actually write protected though.