Metal-oxide resistive random access memories with a single memristor device at the crosspoint (1R RRAM) is a promising alternative to next generation storage technology due to their high density, scalability, non-volatility and low power consumption. However, the imperfect fabrication process introduces high defect rates of the nanoscale memristor devices and leads to yield degradation. In addition, sneak-paths occur in 1R RRAM crossbar that can jeaperdize the normal read/write operation. Previous work proposes voltage bias technique to eliminate the sneak-paths. Instead, in the paper, we leverage voltage bias to manipulate various distribution of sneak-paths that can screen one or multiple faults out of a 4 x 4 region of memristors at once, and consequently diagnose the exact location of each faulty memristor within three write-read operations. The SPICE simulation results highlight the effectiveness and efficiency of the proposed test method.