LG LSC27990ST, Training Manual

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Info Center
Refrigerator Info Center Training
26
Circuit Descriptions
CirCUiT DesCripTions
1-5. Dispenser operation circuit
(1) GR-G277STSA(LSC27990TT)
1) Check load driving status
2) Lever Switch sensing circuit
EXPLANATION FOR MICOM CIRCUIT
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Measuring part
Lever S/W
IC1(Micom) (No. 16)
On
OFF 5V
0 V
(60 Hz)
5 V
Measuring part IC7-15 IC7-14 IC7-13 IC7-12 IC7-11
Status
ON Within 1 V
OFF 12 V
Type of Load
GEARED
MOTOR
SOLENOID
CUBE
PILOT
VALVE
WATER VALVE
WATER
SOLENOID
DISPENSER
LOAD DRIVE STATUS
LEVER SWITCH CIRCUIT
DOOR OPEN CIRCUIT
•Since door switches (A) and (B) are interconnected, if either fails, the other will not respond properly.
•If either switch fails, the light will not come on.
Temperature sensing circuit
1-6. Door opening sensing circuit
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Since door switches (A) and (B) are interconnected, if either fails, the other will not respond properly.
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If either switch fails, the light will not come on.
EXPLANATION FOR MICOM CIRCUIT
- 26 -
Closing 5 V ( A - B , C - D . Switch at both ends are at Off status)
Opening 0 V ( A - B , C - D . Switch at both ends are at On status)
Measuring part
IC1 (MICOM) No. (44, 45) / (45, 46) / (47, 48) Pin
Door of Freezer and Refrigerator
LOAD DRIVE STATUS
LEVER SWITCH CIRCUIT
DOOR OPEN CIRCUIT
•Since door switches (A) and (B) are interconnected, if either fails, the other will not respond properly.
•If either switch fails, the light will not come on.
Temperature sensing circuit
1-7. Temperature sensing circuit
(1) GR-G277STSA(LSC27990TT)
The circuits involving the freezer and refrigerator sensors control the temperature in both the freezer and the refrigerator.
The icemaker sensor detects when ice is made. The defrost sensor determines both the need for defrosting and the
efficiency of the defrost operation. See the table below for voltages and checkpoints.
EXPLANATION FOR MICOM CIRCUIT
- 27 -
SENSOR CHECK POINT NORMAL(-22 °F ~ 122 °F) IN SHORT IN OPEN
Freezing sensor POINT A Voltage
Defrost sensor POINT B Voltage
Refrigerator sensor 1 POINT C Voltage 0.5 V~4.5 V 0 V 5 V
Refrigerator sensor 2 POINT D Voltage
Magic room/ Opti Fresh Sensor POINT E Voltage