Multi F Four-Way Ceiling Cassette Service Manual

- 50 -

Only for training and service purposes

LGE Internal Use Only

Part 5. Trouble Shooting

6.6 Troubleshooting Indoor Error

Ω"

10kΩ"

Check the resistance Check the voltage"

2.5Vdc

Indoor air sensor

Indoor inlet pipe sensor

Indoor outlet pipe sensor

• Open / Short

• Soldered poorly

• Internal circuit error

• Open / Short

• Soldered poorly

• Internal circuit error

• Open / Short

• Soldered poorly

• Internal circuit error

Normal resistor : 10KΩ/ at 25°C (Unplugged)

Normal voltage : DC 2.5V / at 25°C (plugged)

Normal resistor : 5KΩ/ at 25°C (Unplugged)

Normal voltage : DC 2.5V / at 25°C (plugged)

Normal resistor : 5KΩ/ at 25°C (Unplugged)

Normal voltage : DC 2.5V / at 25°C (plugged)

Display

code

Title Cause of error Check point & Normal condition

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 ∞, 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.