The Miller Plasma Spectrum 375 Control Board is the main logic module that drives the plasma cutter’s power supply, torch interface, and user‑interface functions. Common failures on this board include burnt or cracked components around the 24 V/18 V relay circuits, damaged MOSFETs in the output stage, and a shorted power‑input trace that causes the unit to fail to start or display error codes such as “C1” or “E2”. First‑check diagnostics should verify the main AC input voltage and confirm the 24 V/18 V relay contacts are energizing; next inspect the board for visible burn marks, cracked solder joints, or component damage; finally read any stored fault codes via the cutter’s diagnostic display and compare them to the schematic for pinpointing the defective section.[oss-gpt-20b]