Set comprising: - an electronic device with a self-diagnosis function, this device comprising: - a generator adapted to generate at an output a discrete electrical signal that can only assume, at a given time, a single stable state from a discrete set of possible stable states, said discrete set being selected from the group consisting of a discrete set of a plurality of stable voltages and a discrete set of a plurality of stable current intensities, said discrete set of possible stable states including a first and a second predetermined stable state, - a self-diagnosis module (22; 120) capable of generating an error signal indicating a failure, this self-diagnosis module being capable of: - to generate this error signal by being connected only to the output of the generator, and - triggering a timer in response to the discrete electrical signal changing from the first stable state to another state, the timer counting down a predetermined time interval from the time it is triggered, characterised in that: - the self-diagnosis module (22; 120) is also able to: - at the time when the time interval counted by the timer has elapsed, comparing the current state of the discrete electrical signal with the first stable state, and - if the current state is equal to the first stable state, triggering the generation of the error signal and, alternatively, if the current state is different from the first stable state, inhibiting this triggering of the error signal, and - the assembly also comprises an electronic signal processing system capable, by exploiting the error signal generated by the self-diagnosis module, of indicating to a maintenance operator that the generator is showing early signs of failure. - an electronic device with a self-diagnosis function, this device comprising: - a generator adapted to generate at an output a discrete electrical signal that can only assume, at a given time, a single stable state from a discrete set of possible stable states, said discrete set being selected from the group consisting of a discrete set of a plurality of stable voltages and a discrete set of a plurality of stable current intensities, said discrete set of possible stable states including a first and a second predetermined stable state, - a self-diagnosis module (22; 120) capable of generating an error signal indicating a failure, this self-diagnosis module being capable of: - to generate this error signal by being connected only to the output of the generator, and - triggering a timer in response to the discrete electrical signal changing from the first stable state to another state, the timer counting down a predetermined time interval from the time it is triggered, - a generator adapted to generate at an output a discrete electrical signal that can only assume, at a given time, a single stable state from a discrete set of possible stable states, said discrete set being selected from the group consisting of a discrete set of a plurality of stable voltages and a discrete set of a plurality of stable current intensities, said discrete set of possible stable states including a first and a second predetermined stable state, - a self-diagnosis module (22; 120) capable of generating an error signal indicating a failure, this self-diagnosis module being capable of: - to generate this error signal by being connected only to the output of the generator, and - triggering a timer in response to the discrete electrical signal changing from the first stable state to another state, the timer counting down a predetermined time interval from the time it is triggered, - to generate this error signal by being connected only to the output of the generator, and - triggering a timer in response to the discrete electrical signal changing from the first stable state to another state, the timer counting down a predetermined time interval from the time it is triggered, - the self-diagnosis module (22; 120) is also able to: - at the time when the time interval counted by the timer has elapsed, comparing the current state of the discrete electrical signal with the first stable state, and - if the current state is equal to the first stable state, triggering the generation of the error signal and, alternatively, if the current state is different from the first stable state, inhibiting this triggering of the error signal, and - at the time when the time interval counted by the timer has elapsed, comparing the current state of the discrete electrical signal with the first stable state, and - if the current state is equal to the first stable state, triggering the generation of the error signal and, alternatively, if the current state is different from the first stable state, inhibiting this triggering of the error signal, and - the assembly also comprises an electronic signal processing system capable, by exploiting the error signal generated by the self-diagnosis module, of indicating to a maintenance operator that the generator is showing early signs of failure.