The Socapel/Atlas Copco SAM‑DA‑400‑SON‑P4N‑E is a high‑power servo drive designed for 3‑phase motor control with integrated voltage inversion and digital communication options (e.g., fiber optic fieldbus). Common failure modes in this class include overheating of the power MOSFET array, insulation breakdown between DC bus and chassis, and firmware corruption that triggers fault codes or loss of communication. For a first pass, verify the AC input voltage and ensure it matches the drive’s rated range; check the DC bus for correct polarity and continuity to ground; inspect all heat‑sink mounting points and thermal paste for degradation; and review any stored error logs via the drive’s diagnostic interface. If faults persist, proceed with component‑level testing of the MOSFETs, gate drivers, and protection ICs.[oss-gpt-20b]