Power Converter

I have worked on 3 WFCO converters and find them to be solidly built using good quality components. Based on what I've seen their high failure rate is due to one design error: A pair of power resistors that transfer too much heat to the circuit board. They are mounted in contact with the circuit board and either one of the solder joints to the board fails, or the board slowly deteriorates at the base of the resistor and turns into a crispy conductor. Then of course there's the other design error of the converter never going into bulk mode as it's installed by the RV manufacturers.