Re: Never keep trying without diagnosing.
Definitely.
That reminded me of the time when an operator plugged a 3270 terminal in, switched it on and it started emitting smoke. I could just about forgive him for destroying a second terminal by plugging it in to the same socket (after all I'd probably have assumed it was the terminal that was faulty) but not for the third one.
It turned out some dodgy wiring in the factory had resulted in the neutral being connected to one of the phases on the 3-phase supply instead of to where it should have been,