An electronic device, and associated method, provided with a circuit board (10) with a set of input contacts (IN/COM), a set of output contacts (OUT/COM) and an electrical circuit (18) connected between the input contacts (IN/COM) and the output contacts (OUT/COM), and a controller. The controller carries out a real-time test of the circuit board using a test signal introduced into the electrical circuit, the electrical circuit (18) being designed as a passive network having a characteristic transfer function and provided with at least one inductive element, which is formed by a conductor wire (201) wound into a coil around a break (202) in the circuit board (10), which in the assembled condition, is penetrated by a ferromagnetic bar or fixing pin (203), such that the inductance of the inductive element in the assembled state differs from the inductance thereof in the disassembled state.