U3 TROUBLESHOOTING STEPS:

1. Verify High Voltage:

   • Check the power supply for high voltage irregularities.

   • Ensure the voltage supplied to the unit is within the specified range.

2. Examine the Outdoor Fan Motor:

   • Inspect the outdoor fan motor for any visible damage.

   • Check the wiring and connections to the outdoor fan motor.

   • Ensure the fan motor is operating correctly.

3. Check the Stepper Motor:

   • Inspect the stepper motor for any signs of malfunction.

   • Verify the wiring and connections to the stepper motor.

   • Ensure the stepper motor is functioning properly.

4. Examine the Compressor:

   • Inspect the compressor for any visible damage or abnormal operation.

   • Verify the wiring and connections to the compressor.

   • Ensure the compressor is operating correctly.

5. Check the Outdoor Board:

   • Inspect the outdoor board for any signs of malfunction related to PN voltage drop in bus bar protection.

   • Confirm proper wiring and connections on the outdoor board.

   • Look for any visible damage or anomalies on the outdoor board.