[Tom Line]

Until you enabled the jag, you were never sending a PWM signal to it. I'm going to wager you got metal swarf in the jag, and the second you applied a signal it died.

To the best of my knowledge jags still do not have a conformal coating, so the smallest amount of metal inside them can be lethal. Victors are somewhat more reliable in that they have a conformal coating (someone correct me if the jags have changed).