Analysis: Inverter internal FAN is faulty
1. Inspect if the FAN cover plate is deformed
2. Observe if the FAN can normally running( judge it by hearing the running sound or use a hand to feel the wind status)
3. Disconnect the both of AC and DC side switch, after 5 minutes, to check if the FAN connection wire is loose
4. Replace the faulty fan, and observe if inverter can return to normal