The SWI ProtoTRAK SM Controller is a CNC control board used in Southwestern Industries’ ProtoTRAK milling and turning machines, providing motion control, spindle drive, and I/O for tool changers and safety interlocks. Common failure points on this class of controllers include degraded power supply rails (especially the 12 V/24 V DC bus), burnt or blown fuses on the main board, and corrosion or loose connections in the serial/Ethernet communication ports; firmware corruption can also trigger “reset” or “boot loop” symptoms. First‑check diagnostics should verify that the unit receives correct input voltages from the power supply, inspect all connectors for tightness and signs of overheating, and review any displayed error codes on the LCD or through the PC interface to pinpoint a specific subsystem fault.[oss-gpt-20b]