Spellman D6860 is a precision DC high‑voltage power supply used in X‑ray generators, NDT systems and scientific imaging equipment. Common failure modes for this class include overheating of the output transformer or rectifier bridge, degradation of the high‑voltage capacitor bank, and failure of the internal temperature sensor or over‑current protection relay. First‑check diagnostics: verify that the input AC voltage is within spec and that the unit’s main fuse and circuit breakers are intact; inspect the HV output capacitors for bulging or leakage and test the rectifier diodes with a multimeter; review any status LEDs or error codes on the front panel to identify over‑temperature or over‑current conditions.[oss-gpt-20b]