In many cases of failure localization, passive voltage contrast (PVC) localization method does not work, because it is not possible to charge up conducting structures which supposed to be dark in the SEM and FIB images. The reason for this is leakage currents. In this article, the authors show how they succeeded in overcoming these difficulties by the application of the active voltage contrast (AVC) method as it was described as biased voltage contrast by Campbell and Soden. They identified three main cases where the PVC didn't work but where they succeeded in failure localization with the AVC method. This is illustrated with the use of two case studies. Compared to the optical beam based methods the resolution is much better so a single failing contact of e.g. 70 nm technology can clearly be identified which cannot be done by TIVA or OBIRCH.