Case 1858 ยท Public preview
Electrical Degradation May Leave No Definitive SEM Damage
Three optically isolated relay devices had degraded output isolation while their input LEDs remained functional.
Diode testingBiased resistance testingMicrosectioningChemical decapsulationSEMControl comparison
What the evidence preview establishes
The output FET sections were electrically degraded, but physical examination revealed no definitive failure site. The behavior was consistent with low-energy EOS or ESD causing parametric damage below conventional SEM detection limits.
Why this case matters
Visible die damage is not required for electrical degradation. Verify behavior against a control, isolate the affected circuit, and escalate to sensitive electrical-localization methods when SEM findings are inconclusive.
Full evidence reserved for MEMBER and STOREThe complete case includes the evidence sequence, four interpreted figures, alternative explanations, limitations, and practical application guidance.