>>2019054>How do you tell a pantograph is about to break or stop functioning?Depends on the pantograph.
Usually you just need to replace the graphite when it wears with use, usually you'll notice power flicker when the wire hits the worn section of graphite, if it's really bad and you're actively drawing a high load (such as actively accelerating) when the wire goes over the worn area you might even get some pops and flashes, doubly so if you do this on a wire frog.
Though you can also manage to fuck it up in a crash or something where you might need to replace the entire thing.