An unbalanced failure detector circuit according to one aspect of the present disclosure is provided for detecting an unbalanced failure of an electronic device apparatus including electronic devices, and the electronic device apparatus includes a plurality of current paths connected in parallel. The unbalanced failure detector circuit includes a detector unit, and a controller. The detector unit has a plurality of coils connected in series and arranged to surround the plurality of current paths, respectively, and is configured to output a coil sum voltage which is a sum of induced voltages generated across the plurality of coils by currents flowing through the plurality of current paths. The controller is configured to detect the unbalanced failure of the electronic device apparatus when the coil sum voltage outputted from the detector unit exceeds a predetermined value range.