The Respironics California CPS6005A is a high‑current (215 A) ventilator power‑supply main board that converts incoming AC to regulated DC rails for the respiratory control circuitry. Common failures on this model include burned-out bridge rectifier diodes, degraded electrolytic capacitors on the 15 V and 12 V supply lines, and shorted or open MOSFETs in the high‑current switching stage; overheating can also damage the onboard heat sink and PCB traces. First‑check diagnostics: verify input AC voltage and polarity, measure output rail voltages with a calibrated multimeter while the unit is powered on, inspect for visible burn marks or swollen capacitors, and review any diagnostic LEDs or error codes displayed by the ventilator control panel.[oss-gpt-20b]