The Power‑One MPU150‑4530 is a 150 W open‑frame AC‑DC converter with four regulated outputs (+5 V, +3.3 V, +12 V, +12 V). Common failure points in this class include the input PFC MOSFETs, output switching transistors, and the internal voltage regulator IC; overheating or a shorted load can also trigger the built‑in over‑current protection. First‑check diagnostics: verify the 90–264 VAC input is within spec and that the unit’s temperature is below its operating limit; inspect for burn marks or capacitors with bulging/bleeding, then measure each output rail against the datasheet tolerances while the load is disconnected. If any rail is missing or out of range, replace the corresponding switching device or regulator module before proceeding to component‑level repair.[oss-gpt-20b]