LG AUUQ18GH1 Svc Manual page 55

Part 4 Trouble Shooting
Display
Title
code
05
Communication
/
(Indoor÷Outdoor)
53
Check Flow Chart
Check the input power
AC230V (Outdoor,
Indoor unit)
Is it normal ?
( 230V 10% )
Yes
Check the communication
wires are correctly
connected.
Is it normal ?
Yes
Check the resistance
between communication
line and GND.
(Normal : Over 2M)
Is it normal ?
Yes
Is connector for
communication
correctly connected?
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Cause of error
• The connector for trans-
mission is disconnected.
• The connecting wires
are misconnected.
• The communication line
is break
• Outdoor PCB is
abnormal.
• Indoor PCB is abnormal.
• Synchro # of IDU is
abnormal.
No
Needs electric work
No
Adjust the connection
of wire Confirm the
wire of "Live",
"Neutral", "Signal"
No
Correct connection
- 55 -
Check point & Normal condition
• Check power input AC 230V. (Outdoor, Indoor)
• Check connector for transmission
• Check wires are misconnecting.
• Check transmission circuit of outdoor PCB
• Check transmission circuit of indoor PCB
• Check # of IDU setting DIP SW
Is the connection of
GND,GND1,GND2,
No
correctly connected?
Correct connection
Yes
Change PCB
LGE Internal Use Only