LG MULTI V 5 Manual Book page 58

Error
Error No. Error Type Error Type Error Point Error Point
No.
Main PCB of Master
52* Communication
Communication error
unit of Master unit Main PCB of Master unit
error between
Master 521
between of Master unit can't
52* can't receive signal
Slave1 522
(Inverter1/ Inverter2
receive signal from
(Comp1/Comp2 PCB
from Comp1/Comp2
Slave2 523 PCB → Main PCB)
Comp1/Comp2 controller
' Main PCB)
controller
Slave3 524
n Error diagnosis and countermeasure flow chart
Is communication
No Is noise filter or Inverter PCB'S
LED (Yellow) of
Inverter 1 / Inverter 2 line fuse normal?
PCB on?
Yes
No
Is communication cable
Re-connect communication cable
connected correctly?
Yes
No
Is Main PCB normal? Replace Main PCB
Yes
Replace Comp1/Comp2 PCB
* The method of checking Main PCB and Inverter 1 / Inverter 2 PCB (If normal, communication LED blinks)
Fan board Inverter PCB 1
Copyright ©2017 LG Electronics. Inc. All right reserved.
Only for training and service purposes
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Main Reasons Main Reasons
1. Power cable or communication cable is not
1. Power cable or communication cable is not
connected
connected
2. Defect of outdoor Main PCB or Comp1/
2. Defect of outdoor Main PCB or
Comp2 PCB
Comp1/Comp2 PCB
Noise filter or Fuse change
Change Inverter PCB
Inverter PCB 2 Main PCB
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LGE Internal Use Only
Error No. Error Type Error Point
Error
Error Type Error Point
No.
Communication
In case Main PCB
In case Main PCB can't
error
Communication error
53*
53* can't receive signal
(Indoor unit → receive signal from indoor
(Indoor unit ' Main PCB)
from indoor unit
Master
unit
Main PCB)
531
n Error diagnosis and countermeasure flow chart
Is power supplied No
Supply power
to indoor PCB?
1. Check communication cable between External and indoor PCB
Yes
→ Re-connect communication cable
2. Check communication cable between Cycle and External PCB
→ Re-connect communication cable
No
Is communication cable
3. Check communication cable between Cycle and Communication PCB
connected correctly?
→ Re-connect communication cable
4. Check communication cable soldering correctly
Yes
→ Replace communication cable
Are quantity of indoor No
1. Is indoor unit quantity correct after auto addressing
Units installed same as
→ Check Communication PCB
The data of LGMV?
2. Check communication PCB LED blinking
Yes → Replace communication PCB
3. Auto addressing after replace Communication PCB
Check communication cable
→ Check outdoor Main PCB
and installation
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 dis-
played at LGMV is done well then the indoor unit suspected to have some problem (and is not appear at LGMV) may
have following problems
¿ wrong connection of communication cable or power cable
¡ fault of power / PCB / communication cable
¬ 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
Copyright ©2017 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Main Reasons
Main Reasons
1. Communication cables are not connected
between External PCB and indoor PCB
2. Communication cables are not connected
1. Communication cables are not connected between
External PCB and indoor PCB
between Main PCB and External PCB
2. Communication cables are not connected between
3. Communication cables are not connected
Main PCB and External PCB
between Main PCB and Communication PCB
3. Communication cables are not connected between
4. Communication cables are short/open
Main PCB and Communication PCB
5. Indoor PCB power off
4. Communication cables are short/open
6. Defect of outdoor Main/Communication/
5. Indoor PCB power off
indoor PCB 6. Defect of outdoor Main/Communication/indoor PCB
7. Communication wire connection fault
7. Communication wire connection fault
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LGE Internal Use Only
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