LG GR-349SQF Service Manual ▷ View online
5) TEMP SENSOR CIRCUITS
The above circuit reads the surrounding temperature, DEFROSTING temperature and FREEZER ROOM temperature into
MICOM(IC1). OPEN or SHORT state of each SENSOR is as follows.
MICOM(IC1). OPEN or SHORT state of each SENSOR is as follows.
6) SWITCH INPUT CIRCUIT
The following circuit is a test switch input circuit for checking the refrigerator.
- 24 -
(RT– SENSOR)
(DEFROST SENSOR)
(FREEZER COMPARTMENT
SENSOR)
SENSOR)
SENSOR
CHECK POINT
NORMAL (-30
°
C~50
°
C)
SHORT
OPEN
ROOM TEMPERATURE
SENSOR
POINT A Voltage
DEFROST SENSOR
POINT B Voltage
0.5V ~ 4.5V
0V
5V
FREEZER SENSOR
POINT C Voltage
7) TEMPERATURE COMPENSATION
• TEMPERATURE COMPENSATION TABLE by adjusting resistance values. (the temp difference compared to the present
temp.)
eg) If the compensation resistance of freezer compartment is changed from 10K (present resistance) to 18K (revised
resistance), the temp of freezer compartment goes up by +2
°
C.
- 25 -
FREEZER TEMPERATURE
COMPENSATION
FREEZER ROOM
RESISTANCE VALUES(R1)
TEMPERATURE COMPENSATION
REMARKS
180 k
Ω
+ 5.0
°
C
COMPENSATE WARMLY
56 k
Ω
+4.0
°
C
33 k
Ω
+3.0
°
C
18 k
Ω
+2.0
°
C
12 k
Ω
+1.0
°
C
10 k
Ω
0
°
C
STANDARD
8.2 k
Ω
-1.0
°
C
5.6 k
Ω
-2.0
°
C
3.3 k
Ω
-3.0
°
C
2 k
Ω
-4.0
°
C
470
Ω
-5.0
°
C
COMPENSATE COOLLY
• TEMPERATURE COMPENSATION OF FREEZER ROOM
• This circuit is aimed to input the necessary temperature compensation values into the MICOM in order to adjust the freezer
temperature which is different in each model.
- 26 -
Revised resistance
470
Ω
2k
Ω
3.3k
Ω
5.6k
Ω
8.2k
Ω
10k
Ω
12k
Ω
18k
Ω
33k
Ω
56k
Ω
180k
Ω
Present resistance
NOT
1
°
C
↑
2
°
C
↑
3
°
C
↑
4
°
C
↑
5
°
C
↑
6
°
C
↑
7
°
C
↑
8
°
C
↑
9
°
C
↑
10
°
C
↑
470
Ω
COMPENSATE
1
°
C
↓
NOT
1
°
C
↑
2
°
C
↑
3
°
C
↑
4
°
C
↑
5
°
C
↑
6
°
C
↑
7
°
C
↑
8
°
C
↑
9
°
C
↑
2k
Ω
COMPENSATE
2
°
C
↓
1
°
C
↓
NOT
1
°
C
↑
2
°
C
↑
3
°
C
↑
4
°
C
↑
5
°
C
↑
6
°
C
↑
7
°
C
↑
8
°
C
↑
3.3k
Ω
COMPENSATE
3
°
C
↓
2
°
C
↓
1
°
C
↓
NOT
1
°
C
↑
2
°
C
↑
3
°
C
↑
4
°
C
↑
5
°
C
↑
6
°
C
↑
7
°
C
↑
5.6k
Ω
COMPENSATE
4
°
C
↓
3
°
C
↓
2
°
C
↓
1
°
C
↓
NOT
1
°
C
↑
2
°
C
↑
3
°
C
↑
4
°
C
↑
5
°
C
↑
6
°
C
↑
8.2k
Ω
COMPENSATE
FREEZER
5
°
C
↓
4
°
C
↓
3
°
C
↓
2
°
C
↓
1
°
C
↓
NOT
1
°
C
↑
2
°
C
↑
3
°
C
↑
4
°
C
↑
5
°
C
↑
ROOM
10k
Ω
COMPENSATE
(R1)
6
°
C
↓
5
°
C
↓
4
°
C
↓
3
°
C
↓
2
°
C
↓
1
°
C
↓
NOT
1
°
C
↑
2
°
C
↑
3
°
C
↑
4
°
C
↑
12k
Ω
COMPENSATE
7
°
C
↓
6
°
C
↓
5
°
C
↓
4
°
C
↓
3
°
C
↓
2
°
C
↓
1
°
C
↓
NOT
1
°
C
↑
2
°
C
↑
3
°
C
↑
18k
Ω
COMPENSATE
8
°
C
↓
7
°
C
↓
6
°
C
↓
5
°
C
↓
4
°
C
↓
3
°
C
↓
2
°
C
↓
1
°
C
↓
NOT
1
°
C
↑
2
°
C
↑
33k
Ω
COMPENSATE
9
°
C
↓
8
°
C
↓
7
°
C
↓
6
°
C
↓
5
°
C
↓
4
°
C
↓
3
°
C
↓
2
°
C
↓
1
°
C
↓
NOT
1
°
C
↑
56k
Ω
COMPENSATE
10C
↓
9
°
C
↓
8
°
C
↓
7
°
C
↓
6
°
C
↓
5
°
C
↓
4
°
C
↓
3
°
C
↓
2
°
C
↓
1
°
C
↓
NOT
180k
Ω
COMPENSATE
8) LIGHTING CIRCUITS OF KEY BUTTON INPUT AND DISPLAY PARTS
The above circuit is to judge the operation conditions of function key and to light each function indicating LED. It is operated
by SCAN method.
by SCAN method.
- 27 -
FREEZER TEMP
CONTROL KEY
CONTROL KEY
DISPLAY PART
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