LG LCN240CP Service Manual page 42

Troubleshooting Guide
Troubleshooting CH05, CH53
Display
Title
code
05
Communication
/
(Indoor ¡ Outdoor)
53
Check Point
1. Check the input power AC230V. (Outdoor, Indoor unit)
2. Check the communication wires are correctly connected.
¡ Adjust the connection of wire
¡ Confirm the wire of "Live", "Neutral"
3. Check the resistance between communication line and GND. (Normal : Over 2MΩ)
4. Check the connector for communication is correctly
connected.
5. Check the connection of GND1, GND2, and main GND.
6. If one indoor unit is operated normally, outdoor PCB is no problem.
¡ Check the another indoor unit.
* CH05 is displayed at indoor unit, CH53 is displayed at outdoor unit.
42 Ceiling Cassette Air Conditioner
Cause of error
• Communication poorly
Check point & Normal condition
• Power input AC 220V. (Outdoor, Indoor)
• The connector for transmission is disconnected.
• The connecting wires are misconnected.
• The GND1,2 is not connected at main GND.
• The communication line is shorted at GND.
• Transmission circuit of outdoor PCB is abnormal.
• Transmission circuit of indoor PCB is abnormal.