LG ARUN Series Service Manual page 109

Error
Error Type
No.
Communication error
53
(Indoor unit ➔ Main PCB)
I Error diagnosis and countermeasure flow chart
Are quantity of indoor
units installed same as
the data of LGMV?
Yes
Is power supplied
to indoor units?
Yes
Replace indoor unit PCB or
communication PCB
after check defected indoor
In case of CH53, almost happened with CH05, the indoor units not operated actually are normal so check with
same method of CH05. and additionally check as shown as below and above flow chart
• Although the quantity of indoor units installed is same as LGMV data there may be a few indoor units with
which the number of communication is not increased with LGMV
• Although the quantity of indoor units installed is not same as LGMV data, and if communication of the indoor
unit displayed at LGMV is done well then the indoor unit suspected to have some problem (and is not appear at
LGMV) may have following problems
➀ wrong connection of communication cable or power cable
➁ fault of power / PCB / communication cable
➂ duplication of indoor unit number
• If communication is not doing well wholly then the Auto Addressing is not done
• The case that CH53 appear at indoor unit also Auto Addressing is not done so indoor unit address may be
duplicated
* After replacement of indoor unit PCB, Auto Addressing should be done, if central controller is installed then the
central control address also should be input.
In case that only communication PCB is replaced above process is not needed
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Only for training and service purposes
Error Point
In case Main PCB can't
receive signal from indoor
unit
Is indoor unit
No
quantity correct after
Auto Addressing?
Yes
End
No
Supply power
1. Communication cables are not connected
2. Communication cables are short / open
3. Defect of outdoor Main / indoor PCB
No
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Troubleshooting Guide
Main Reasons
LGE Internal Use Only