Hello again,
So, now, I'm failing the shunt test. When I plug and touch the first MJE5731A, there is some initial high voltage, but it drains very fast to 0. And if I go to the second, I get a null reading. On the plus side, the leds do turn red. Just posting a couple of pictures in case there is something obvious, before going back to inspect the wiring. As usual, all hints are welcome.