Basic overcurrent protection? In my sci-fi?

Next you’re gonna tell me you can’t just “re-route power” by pressing buttons on a screen and not, you know, actually unhooking any wires!

How do you know the buttons don't trigger relais or the like which then actually unhook the wires?

Judging from what things look like when they open up the walls, they could just be telling the system to use a specific circuit path. It looks like everything is just a bunch of blocks or cards with super dense computer chips on them and half the repairs we ever see are just these being unslotted and replaced. The other half being waving fake tools around.