Before blaming the unit, a technician must verify the basics. Low voltage (brownout conditions) or a severely imbalanced power supply can prevent the compressor from developing sufficient starting torque. Additionally, loose or corroded wiring connections between the main board, the IPM, and the compressor terminals can introduce resistance, starving the compressor of the necessary inrush current.
. Contact an electrician to investigate your home's power supply. 4. Inspect Wiring and PCB If the incoming power is stable but the error persists: Visual Inspection: o general ac error code 9c