Pioneer Magnetics PM3275A‑6‑5 is a high‑current, low‑voltage switch‑mode power supply commonly used in industrial control racks and VME bus systems. Common failure modes for this class include capacitor degradation on the output filtering stage, transformer core saturation due to over‑current or miswired input, and MOSFET gate driver burnout from excessive ripple voltage. Begin diagnostics by verifying that the AC input is within spec and measuring the DC output rails with a multimeter; check for any visible signs of overheating or burn marks on the PCB, especially around the power MOSFETs and heat sinks; finally review any error logs or status LEDs that may indicate over‑temperature or short‑circuit protection activation.[oss-gpt-20b]