Outdoor Board LED1 (green) blinks four times and LED2 (red) blinks three times alternately - Abnormality of power module

What does U3, U4 mean?

During startup or operation, the outdoor unit's LED1 (green) blinks four times and LED2 (red) blinks three times alternately, indicating an abnormality within the power module.

• Abnormality of power module.
• Faulty power module components.
• Power supply issues affecting the module.

Click steps to track your progress.

1. 1

   Check for looseness, disconnection, or incorrect connection of the compressor wiring, as power module issues can impact the compressor.

2. 2

   Measure resistance values among terminals on the compressor using a tester to rule out related issues.

3. 3

   Ensure the power supply voltage is stable and within specifications.

4. 4

   If the error persists, the power module likely requires professional inspection or replacement.