A fault detection device includes at least one electricity generating unit, to impress a signal on a first useful signal path； at least one first comparison unit, to determine if the signal of the first useful signal path lies within a measuring range； and at least one first interference signal path, designed as a current measurement path, for current-detecting measurement of a first interference signal. A signal path defect analysis unit, is included to detect a signal path defect, upon the impressed signal not being measured on the at least one first interference signal path and upon the checked signal of the comparison unit being determined to lie within the measuring range. Furthermore, corresponding methods are for the detection of signal path defects in a voltage measuring system for measuring bioelectric signals are defined.
