LG CASSETTE AIR CONDITIONER LCN240CP - LCN380CP Error ode and troubleshooting - Air conditioner service and repair

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INDOOR UNIT LCN240CP - LCN380CP

OUTDOOR UNITLCU240CP - LCU380CP


Self-diagnosis Function
Error Indicator
# The function is to self-diagnoisis airconditioner and express the troubles identifically if there is any trouble.
# Error mark is ON/OFF for the operation LED of evaporator body in the same manner as the following table.
# If more than two troubles occur simultaneously, primarily the highest trouble fo error code is expressed.
# After error occurrence, if error is released, error LED is also released simultaneously.
# To operate again on the occurrence of error code, be sure to turn off the power and then turn on.
# Having or not of error code is different from Model.
Troubleshooting CH01, CH02, CH06
Display code
Title
Cause of error
Check point & Normal condition
01


Indoor air sensor


Open / Short
Soldered poorly
Internal circuit error
Normal resistor : 10KΩ/ at 25°C (Unplugged)
Normal voltage : 2.5Vdc / at 25°C (plugged)



02




Indoor inlet pipe sensor



Open / Short
Soldered poorly
Internal circuit error


Normal resistor : 5KΩ/ at 25°C (Unplugged)
Normal voltage : 2.5Vdc / at 25°C (plugged)



06


Indoor outlet pipe sensor

Open / Short
Soldered poorly
Internal circuit error


Normal resistor : 5KΩ/ at 25°C (Unplugged)
Normal voltage : 2.5Vdc / at 25°C (plugged)

 Check Point
1. Unplug the sensor on Indoor unit PCB.
2. Estimate the resistance of each sensor.
3. If the resistance of the sensor is 10KΩ/ 5KΩ at 25°C, then sensor is normal.
4. If the resistance of the sensor is 0 KΩ or infinite, then sensor is abnormal. > Change the sensor.
5. Plug the sensor on Indoor unit PCB and Power ON.
6. Estimate the voltage of each sensor.
7. If the voltage of the sensor is 2.5Vdc at 25°C, then sensor is normal.
8. If the resistance of the sensor is 0 or 5Vdc, then sensor is abnormal.  >Repair or Change the PCB.
Troubleshooting CH03
Display code : 03
Title: Communication Wired R/C
Cause of error
# Open / Short
# Wrong connection
Check point & Normal condition
Connection of wire
Main PCB Volt. DC12V
Noise interference
Check Point
1. Check the wire connection. (Open / Short) >  Repair the connection
2. Check the soldering state of connector. (Soldered poorly) > Repair or Change the PCB.
3. Check the volt. Of main PCB power source. (DC 12V, DC 5V)> Repair or Change the main PCB.
4. Check the installation of wired remote controller. (Noise interference) > Adjust the state of installation
Troubleshooting CH04
Display code : 04
Cause of error
Drain pump / Float switch
Cause of error
# Float switch Open (Normal : short)
Check point & Normal condition
The connection of wire(Drain pump/ Float switch)
Drain pump power input. (220V)
Drain tube installation.
Indoor unit installation. (Inclination)
Check Point
1. Check the wire connection. (Open, Soldered poorly)  > Repair the connection or change the PCB.
2. Check the resistance of float switch (Abnormal : Open, Normal : short) > Check the float switch.
3. Check the level of water
4. Check the volt. Of Drain pump power supply. (AC 230V) >  Repair or Change the main PCB.
Troubleshooting CH05, CH53
Display code : 05/53
Cause of error
Communication
(Indoor > Outdoor)
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.
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.
Troubleshooting CH24, CH25
Display code
Title
Check point & Normal condition
24

Press S/W Open

Check the connection of “CN_Press”.
Check the components.

25

Input voltage
Check the power source.
Check the components.
Check Point
# CH 24
1. Check the connection of “CN_PRESS”
2. Check the install condition for over load.
3. Check the SVC V/V open.
4. Check the leakage of refrigerant.
# CH 25
1. Check the power source.
2. Check the components
(Trans1, B/Diode, Diode, Resistance)