The Yamabishi SE‑PW is a modular switch‑mode power supply designed for industrial drives and control systems, accepting 170–253 VAC at 50/60 Hz and providing 5, 8, 18 or 24 VDC outputs. Common failure modes include degraded electrolytic capacitors on the input/output rails, blown output fuses, and malfunctioning switching regulators that cause voltage sag or over‑current shutdowns; overheating of the heat sink can also trigger protection trips. First‑check diagnostics should verify input AC voltage and phase balance, inspect all capacitors for bulging or leakage, and confirm each DC rail with a multimeter while monitoring for ripple or dropout under load. Additionally, review any error codes from connected drives and check the status LEDs on the SE‑PW board for fault indications.[oss-gpt-20b]