LG MULTI V M ARNU07GTU 4 Series Svc Manual page 81

Error No. Error Type
Inv. PCB Heatsink
621
Temperature High
n Error diagnosis and countermeasure flow chart
Is Installation
Condition Normal?
Yes
Inv. PCB IPM Connection
Condition Normal?
Yes
Is ODU Fan Motor Normal?
Yes
Is Inv. PCB assembly
Normal?
Yes
Recheck Power and
Installation Condition
n Check Inv. PCB Screw Connection Condition
Check Screw Connection Condition
Error Point
Heatsink Temperature
is Over 90°C
1. Check Pipe Clogging/ Distortion
2. Check Covering (Outdoor/Indoor Unit)
No
3. Check EEV Connector Assemble Condition/Normal Operation
4. Check Refrigerant Pressure
5. Check Power Wire/ Connection Condition
Reassemble or Manage if abnormality Found
No
1. Check Inv. PCB Screw Connection Condition
Reassemble or Manage if abnormality Found
No
1. Check Compressor module Fan Motor Operation or Lock
Reassemble or Manage if abnormality Found
No
1. Reset
Replace Inv. PCB Assembly
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Troubleshooting Guide
Main Reasons
1. Inv. PCB IPM Connection Condition Abnormal
2. Compressor module Fan Motor Operation Abnormal
3. Compressor module Inv. PCB Assembly Defect
4. Overload Operation (Pipe Clogging/ Covering/EEV
Defect/Ref. Overcharge)
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