Speaking of exploding consoles, when was the first time we saw one that caused injury and/or was fatal?
I'd have to say the earliest depiction of lethal exploding consoles was in TWOK, though it was only fake-lethal in the simulator.
I have an impression there was a TOS episode where somebody -- I want to say Uhura -- had their hands burned by an electrical surge from their console. But I'm not at all sure that happened.
I've gone through my old, old pencil-and-paper list of Enterprise
personnel from TOS, which includes an X by the name of each killed crewperson, and the closest thing to "death by console" is poor Mr. Harper, who was disintegrated by the M5 computer's power beam in "The Ultimate Computer." But that's not very close at all, really.