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DIAGNOSIS AND SOLUTION (CONT)
Zero crossing detection error diagnosis and solution (E2)
Error Code E2
Malfunction decision conditions
When the PCB does not receive a zero crossing signal feedback for 4 minutes or the zero crossing
signal time interval is abnormal.
Supposed causes
S Connection mistake
S PCB faulty
Troubleshooting
Check if the connections and
power supply are normal. 
Correct the connections. Turn on the 
unit when the power supply is good.
No
Yes
Indoor main PCB is 
defective. Replace indoor 
main PCB.