LG GR-349SQF Service Manual ▷ View online
• 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
3. SENSOR RESISTANCE CHARACTERISTICS TABLE
• The tolerance of sensor resistance is
±
5%.
• Be sure to measure the sensor resistance after keeping the sensor more than 3 minutes at a measuring temperature.
(It needs delay due to sensor speed.)
• Measure the resistances of SENSORs with a digital tester after disconnecting CON 4 of MAIN PWB ASSY.
- 28 -
MEASURED TEMPERATURE
RESISTANCE OF FREEZER SENSOR
RESISTANCE OF DEFROST SENSOR, ROOM TEMPERATURE SENSOR
-20
°
C
22.3k
Ω
77k
Ω
-15
°
C
16.9k
Ω
60k
Ω
-10
°
C
13.0k
Ω
47.3k
Ω
-5
°
C
10.1k
Ω
38.4k
Ω
0
°
C
7.8k
Ω
30k
Ω
+5
°
C
6.2k
Ω
24.1k
Ω
+10
°
C
4.9k
Ω
19.5k
Ω
+15
°
C
3.9k
Ω
15.9k
Ω
+20
°
C
3.1k
Ω
13k
Ω
+25
°
C
2.5k
Ω
11k
Ω
+30
°
C
2.0k
Ω
8.9k
Ω
+40
°
C
1.4k
Ω
6.2k
Ω
+50
°
C
0.8k
Ω
4.3k
Ω
4. MAIN PWB ASS'Y AND PARTS LIST
1) MAIN PWB ASS'Y
- 29 -
DIP
CE1
+
CM1
CM2
+
+
CE2
CE6
CE3
+
J06
J07
J01
+
IC3
CC1
CC2
CE4
+
CE5
D5
OP2
R21
OP1
R20
CC4
R6
CC10
R19
J05
J10
J11
J02 R7 J04
RF3
R10
R1
CC8
CC7
R16
R15
R17
RF2
RF1
TEST
R13
R12
R11
IC4
J09
IC1
CC3
J08
6871JB1037
STICKER
J12
Q1
J13
Q2
J14
Q3
R14
CC6
CC5
OSC1
R8
R9
CC9
1
D
6
R-DOOR
F
CON3
RT-SENSOR
9
1
CON2
98 12
COMP
F-FAN
D-HEATER
CON1
VA1
RY2
RY3
RY1
D8
D7
J15
D6
R4 R18 R3
BUZZER
Q4
IC6
TRANS
D1
D3
D4
D2
IC2
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