LG MULTI V M ARNU07GTU 4 Series Svc Manual page 79

Error
Error Type
No.
Communication error : Main
571
PCB --> Inv. PCB
n Error diagnosis and countermeasure flow chart
Are there any
communication wire
connections normal?
Yes
Is Inv. PCB
assembly
normal?
Yes
Is there any error
when power reset?
No
Recheck power and
installation condition
Main PCB
Error Point
Failing to receive inverter
signal at main PCB of
Compressor module
No
1. Check communication wiring conditions
2. Check connector conditions
→ Rewire them if abnormality found.
No
1. Replace Inv. PCB
Yes
1. Replace Main PCB
Communication wire
- 79 -
Troubleshooting Guide
Main Reasons
1. Bad Connection Between Main PCB and
Inv. PCB
2. Communication Wire Noise Effect
3. ODU Main PCB Damage
Inv. PCB
Copyright © 2018 LG Electronics Inc. All rights reserved.
Only training and service purposes.