LG LT-D3680CL / LT-D3680HL / LT-D3682HL / LT-D4820CL / LT-D4820HL / LT-D4822HL / LT-D4880CL / LT-D4880HL Service Manual ▷ View online
Cycle Troubleshooting Guide
Trouble analysis
1. Check temperature difference between intake and discharge air and operating current.
Temp. Difference
Temp. difference : approx. 0°C
Current : less than 80% of
Current : less than 80% of
rated current
Temp. difference : approx. 8°C
Current : less than 80% of
Current : less than 80% of
rated current
Temp. difference : less than 8°C
Current : over the rated
Current : over the rated
current
Temp. difference : over 8°C
Operating Current
All amount of refrigerant leaked out
Check refrigeration cycle
Check refrigeration cycle
Refrigerant leakege
Clog of refrigeration cycle
Defective compressor
Clog of refrigeration cycle
Defective compressor
Excessive amount of refrigerant
Normal
Notice :
Temperature difference between intake and discharge air depends on room air humidity. When the room air
humidity is relativery higher, temperature difference is smaller. When the room air humidity is relatively lower
temperature difference is larger.
Temperature difference between intake and discharge air depends on room air humidity. When the room air
humidity is relativery higher, temperature difference is smaller. When the room air humidity is relatively lower
temperature difference is larger.
2. Check temperature and pressure of refrigeration cycle.
Notice :
1. The suction pressure is usually 4.5~6.0 kg/cm
1. The suction pressure is usually 4.5~6.0 kg/cm
2
G at normal condition.
2. The temperature can be measured by attaching the thermometer to the low pressure tubing and wrap it with
putty.
Suction pressure
Temperature
(Compared with
(Compared with
Cause of Trouble
Description
the normal value)
the normal value)
Defective compressor
Current is low
Defective 4-way reverse valve
Excessive amount of
High pressure does not quickly
Normal
refrigerant
rise at the beginning of
operation
operation
Insufficient amount of
Current is low
Lower Higher
refrigerant
(Leakage)
Clogging
Current is low
High
Higher
–39–
Electronic Parts Troubleshooting Guide
: The unit does not operate.
Possible Trouble 1
–40–
YES
NO
YES
Is the input voltage
of transformer AC230V?
Check the FUSE
and the wiring diagram.
and the wiring diagram.
Is the PIN 49,58 of
MICOM. DC5V?
Exchange MICOM.
YES
NO
Check the main P.C.B
pattern.
pattern.
NO
YES
Is the output voltage
of IC03D DC5V?
NO
Exchange IC03D.
Is the input voltage
of IC03D about DC12V?
Check the
5V P.C.B pattern.
5V P.C.B pattern.
Possible Trouble 2
: The indoor fan does not operate.
–41–
NO
NO
Is it the HOT
START mode?
Is IC01M operated
normally?
Check the fan motor
and connector.(CN-MOTOR)
and connector.(CN-MOTOR)
YES
Is the each Relay
any problem?
YES
NO
YES
It is normal operation.
Exchange IC01M.
Exchange Relay.
YES
YES
NO
YES
Is it Heating Mode?
Does the temperature
set all right?
Change IC01M.
NO
NO
Adjust operation mode.
Adjust set temperature.
Is IC01M operated
normally?
YES
Check the connector.
(CN-OUT)
(CN-OUT)
Check RY-4Way.
NO
Is 4way-valve operated?
Possible Trouble 3
: Ineffective Heating
–42–
Possible Trouble 4
: Auto Air direction louver does not operate.
Possible Trouble 5
: Wired remote controller does not operate.
YES
NO
Is IC01M operated
normally?
Check the motor and
connector.
(CN-LOUVER)
connector.
(CN-LOUVER)
Exchange IC01M.
NO
YES
YES
YES
Is the LCD operated
normally?
Is the terminal of wired
Remocon T2 DC12V?
Is the pin 39, 40 of
Micom DC 5V?
Change the wired Remocon.
Check the wired Remocon
PCB and DC 12V pattern.
PCB and DC 12V pattern.
NO
NO
Check the parts of
communication.
communication.
Connector CN-Remo, and
terminals of wired
Remocon exactly.
terminals of wired
Remocon exactly.
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