Methods for reliability testing include applying a stress voltage to a device under test (DUT); measuring a leakage current across the DUT; triggering measurement of optical emissions from the DUT based on the timing of the measurement of the leakage current; and correlating measurements of the leakage current with measurements of the optical emissions to determine a time and location of a defect occurrence within the DUT by locating instances of increased noise in the leakage current that correspond in time with instances of increased optical emissions.