Various embodiments related to identifying a candidate defect region in a semiconductor device are disclosed. For example, one embodiment includes receiving an electrical test mismatch reported for a scan chain; generating a physical representation of portion of a logical design of the semiconductor device, the physical representation including location information for physical instantiations of logical cells and logical interconnections included in the portion of the logical design; identifying a suspect logical region in the physical representation, the suspect logical region including a portion of the logical cells and the logical interconnections electrically connected with the scan chain; generating a candidate defect region within the semiconductor device, the candidate defect region being defined, via the physical representation, to include the physical instantiations of logical cells and logical interconnections included in the suspect logical region; and displaying the candidate defect region.