LG R410A Service Manual page 173

Error
Error Contents
Code
Communication
error
57
(Main PCB '
inverter PCB )
Error
Error Contents
Code
Excess of heat in
inverter PCB heat
62
sink
I Defect inspection method
1) Check whether the heat sink cooling fan is normal ?
Check the power supply connector to the cooling fan of the heat sink on the upper side of the Main PCB is
12Vdc (Always operating when the inverter comp is operating)
Also check the heat sink cooling fan Lead-Wire
2) Check whether the air is coming out from the cooling fan of the heat sink on the upper side of the of the control
box.
Check the assembly condition in the surrounding of the heat sink
6) In case the above given 4,5, the fan is not working then replace the cooling fan.
7) Check the compressor IPM and replace of required.(refer: error code 21)
8) Check if the fan IPM is normal. Otherwise, replace the IPM .
9) In case the error persists even after the fan IPM is replaced then replace the fan main PCB .
Meaning
Main PCB cannot receive
the signal from the inverter
PCB
Meaning
Excessive rise of
Inverter heat sink tempera-
ture
Main Causes
Refer to CH52
Main Causes
1. Defective heat sink fan
2. Overheat of the inverter comp IPM
3. Inverter fan IPM overheat
4. Defective fan Main PCB
5. Defective heat sink region connec-
tion
6. Defective heat sink fan power sup-
ply terminal
Troubleshooting Guide
Error display
position
Error display
position
Concerned
Remote
Controller
Outdoor unit
Service Manual 173