The Electro Scientific Industries 65‑61839 is a DC power supply module used in industrial laser‑micromachining and precision control systems, typically providing +15 V, –15 V, +12 V, and +5 V rails. Common failure modes for this class include degraded output regulation due to aging linear regulators or switching components, overheating of the heat sink leading to thermal shutdown, and insulation breakdown causing short circuits between rails. First‑check diagnostics: verify input voltage and polarity with a multimeter, measure each rail against ground for correct voltage levels and ripple; inspect the module for visible signs of burn marks, cracked PCBs, or swollen electrolytic capacitors; review any error codes or status LEDs on the host controller that may indicate power supply faults.[oss-gpt-20b]