Lost one to science, it happens. Edison lost a few, too. I kind of thought operating these at the max was a recipe.
Did you note final voltage at 36-38 amps before the blue smoke came? Was it 38.89 amps at 15.33V?
I would theorize that operating the output at it's maximum is sending the transistors into oscillation. Anytime that type of switching is taking place, there is bound to be some bad things happening unless the condition is changed.
Nice job on the plate cleanup, though. Getting everything flat as can be is where it's at.
Awaiting the autopsy.
