The Seco Electronics 8600 is a 220 VAC, 15 A SCR motor speed control unit designed for low‑power industrial drives (up to ~2 HP). Common failure points in this class include worn SCRs or gate driver circuits, degraded capacitors on the input filtering board, and insulation breakdown between the field/armature windings. Initial checks should verify proper 220 VAC supply and correct polarity, inspect for visible burn marks or capacitor bulging, and confirm that the output voltage range (0–180 VDC) is within spec using a multimeter. If error codes are available on the unit’s status LED or diagnostic port, review them against the Seco service manual for specific fault indications.[oss-gpt-20b]