LG LS-M3021CL Service Manual page 60

Check the connector of intake and pipe sensor(thermistors)
• Check the related circuit of R02H(12.1K), R04H(6.2K), R03H(1.0K),
Micom(No. 3, 4).
• Check the indoor room temperature is disconnected or not (about
10KΩ/at 25°C).
• Check the indoor pipe temperature is disconnected or not (about
5KΩ/at 25°C).
• The details of check are as followings
• Comp Relay.
CHECK POINT COMP. ON
Between Micom
(No.15) and GND
Between RY-COMP.
About DC12V
(No.1) and (No.4)
Between
CN-COMP2 and AC 220~240V
CN-POWER 2(N)
• 4 way Relay
CHECK POINT COMP. ON
Between Micom
(No.13) and GND
Between RY-4WAY
About DC12V
(No.1) and (No.4)
Between CN-4WAY
and AC 220~240V
CN-POWER 2(N)
• Check the electrical wiring diagram of outdoor side.
• Check the abnormal condition for the component of
Compressor/Outdoor Fan Motor, 4 way.
• Check the "open" or "short" of connecting wires between indoor and
outdoor.
Check the DC voltage on the PWB ASS'Y
COMP. OFF
DC5V DC0V
DC0V
Below AC10V
COMP. OFF
DC5V DC0V
DC0V
Below AC10V
Turn off Main Power
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• Outdoor fan Relay
CHECK POINT COMP. ON
Between Micom
(No.14) and GND
Between RY-FAN
About DC12V
(No.1) and (No.4)
Between CN-FAN
and AC 220~240V
CN-POWER 2(N)
COMP. OFF
DC5V DC0V
DC0V
Below AC10V