The Digital Concepts 450HRC is a dedicated power‑conversion unit that supplies regulated AC and DC rails to the True Fitness 450 HRC treadmill’s motor, control board, and accessory circuits. Common failure modes in this class of industrial power supplies include overheating due to inadequate ventilation, degradation of input capacitors or output rectifiers, and failure of fuses or protection relays under over‑current conditions. First‑check diagnostics: verify the unit is receiving its rated input voltage (typically 120 VAC) with a multimeter; inspect for visible signs of thermal damage or blown fuses on the power board; confirm that all output rails (12 V, 24 V, etc.) are within specified tolerances and that no error codes are present on the treadmill’s display or control panel.[oss-gpt-20b]