Haier AS18ND3HAA Service Manual page 31

Check the connector connection.
Thermistor resistance check
Thermistor resistance check method:
Remove the connector of the thermistor on the PCB, and measure the resistance of thermistor using tester.
The relationship between normal temperature and resistance is shown in the value of indoor thermistor.
10.4.2.2 EEPROM abnormal
Indoor Display E4: indoor EEPROM error
Method of
Method of The Data detected by the EEPROM are used to determine MCU
Method of
Malfunction
Malfunction
Malfunction
Detection
Detection
Malfunction
Malfunction
Malfunction when the data of EEPROM is error or the EEPROM is damaged
D c e s i o i n
Detection
Decision
Conditions
Conditions
Supposed
Supposed
Supposed
Causes
Causes
Causes
Troubleshooting
Troubleshooting * Caution Be sure to turn off power switch before connect or disconnect connector,
or parts damage may be occurred.
Is it normal?
Yes
Yes
Is it normal?
Faulty EEPROM data
Faulty EEPROM
Faulty PCB
Replace the indoor or outdoor mainboard
No
Correct the connection
No
Replace the thermistor
Yes
Replace the indoor unit PCB
29
Service diagnosis
Domestic air conditioner