LG TN-C090BT00 Service Manual page 28

5. Error Mode & Corrective Method
Cause of error
Error mode
OPEN/SHORT of
CH01
room temp.
sensor
OPEN/SHORT of
CH02 indoor pipe temp.
sensor
Communication
Error
CH03
Communication of
indoor and outdoor
CH05
Error
CH18 Pressure Error
Sensing condition of error
Voltage of sensing: Over 4.8V
Voltage of sensing: Less than
0.5V
Voltage of sensing: Over 4.8V
Voltage of sensing: Less than
0.5V
Communication interruption
between remote controller and
Main PCB for 2 minutes.
Connecting cable connected to
indoor and outdoor unit connect
wrong or badness.
Pressure of system:
Hig er than high pressure h
switch spec / lower than low
pressure switch spec.
28
Method of SVC
1. Check the voltage of "CO1H"
on the remote controller.
2. Check the temp. sensor of
remtote controller.
1. Check the voltage between PIN 3
and 4 of CN-A cycle/CN-B cycle.
2. Check the temp. sensor of
indoor pipe.
1. Check the connecting wire
between main PCB remote
controller.
2. Check the input voltage of
remote-controller.
3. Check the wiring of
remote-controller.
1. Check the connection
between connecting cable
and T/B.
2. Check the sequence of the
connecting cable.
1. Check the refrigerant of
the system.
2. Check the leakage of system.
3. Check the pressure switch.
Remark
Room
temp.(25 C)
= DC 2.5V
Pipe temp.(25 C)
= DC 2.2V
Input voltage of
remote-controller
= DC 12V
For all models
For TN-C180BT00/
TN-C240BT00.It
may at least one of
the four switches
has action.