A terminal had reduced contact area
The defect was concealed behind the device.
↓A damaged connection produced resistance heating, odor and intermittent buzzing before visible scorching developed.
The defect was concealed behind the device.
↓The symptom followed appliance use rather than weather.
↓This combination required a safety stop rather than online disassembly.
↓The case remained isolated until the circuit was made safe.
The autopsy preserves how evidence connected them without collapsing uncertainty into one magic answer.
A damaged connection produced resistance heating, odor and intermittent buzzing before visible scorching developed.
The investigation followed the source, transport path, affected material and verification step separately.
Timing and location evidence ruled out attractive but weaker explanations before repair work began.
Repair the controlling source and then verify the outcome under the conditions that previously triggered the symptom.