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Desktop CT and 3D Scanner With Arduino
It's an inductive coil, simply magnet wire wound around a core. You should test the continuity of the posts with a multi-meter to make sure there is no break in the wire. If that is fine there is probably not a problem with it. It is far more likely that your batteries have failed. You can test them with the voltage meter of the multi-meter. If they are less than 1V they are most likely garbage and need to be replaced. They can be put into a AA Ni-Mh charger to see if they will charge.
Build your own 3d printer filament factory (Filament Extruder)
Charcoal Powered Generator - Gasifier
Laptop Battery Analyzer /Recycler