LG GR-B-L207EC-ER Service Manual ▷ View online
1-10. Key Button Input and Display Lighting Circuit
1. GR-P247, GR-P207, GR-L247, GR-L207
This circuit is to judge the work of function control button on the operation panel and to light each function indication led
(LED module). It is driven by SCAN method.
(LED module). It is driven by SCAN method.
2. GR-C247, GR-C207, GR-B247, GR-B207
MICOM CIRCUIT DESCRIPTION
- 41 -
FRZ
TEMP
REF
TEMP
SELECT
R
S
T
Max
Min
F1
F2
F3
F4
F5
R1
R2
R3
R4
R5
Freezer
Temp
Control
Temp
Control
Refrigerator
Temp
Control
Temp
Control
Crushed
/Water
/Cube
/Water
/Cube
Freezer
Temp
Control
Temp
Control
Refrigerator
Temp
Control
Temp
Control
2. Sensor Resistance Characteristic Table
• Tolerance of sensor resistance is
±
5 %.
• Leave the sensor at measuring temperature for more than 3 minutes when measuring sensor resistance.
(necessary due to detecting speed)
• It is desirable to use digital tester as analogue tester has wider measuring temperature.
• Disassemble refrigerator sensor 1 and 2 from CON8 of main PWB assembly and measure it with digital tester.
• Disassemble freezer sensor from CON7 of main PWB assembly and measure it with digital tester.
MICOM CIRCUIT DESCRIPTION
- 42 -
Measured Temperature (
°
C)
Freezer Sensor
Refrigerator Sensor 1 and 2, Defrost Sensor and
Open Air Sensor
-20
°
C
22.3 k
Ω
77 k
Ω
-15
°
C
16.9 k
Ω
60 k
Ω
-15
°
C
13.0 k
Ω
47.3 k
Ω
-5
°
C
10.1 k
Ω
38.4 k
Ω
0
°
C
7.8 k
Ω
30 k
Ω
+5
°
C
6.2 k
Ω
24.1 k
Ω
+10
°
C
4.9 k
Ω
19.5 k
Ω
+15
°
C
3.9 k
Ω
15.9 k
Ω
+20
°
C
3.1 k
Ω
13 k
Ω
+25
°
C
2.5 k
Ω
11 k
Ω
+30
°
C
2.0 k
Ω
8.9 k
Ω
+40
°
C
1.4 k
Ω
6.2 k
Ω
+50
°
C
0.8 k
Ω
4.3 k
Ω
3. PWB Parts Drawings and List
3-1. PWB Assembly Main Parts Drawings
1 GR-P247, GR-P207, GR-L247, GR-L207
MICOM CIRCUIT DESCRIPTION
- 43 -
1
STICKER
6871JB1064
LG
32
1
ON
OFF
ON
OFF
J36
ZD2
ZD3
DUCT
HTR
CON6
[DISPLAY]
11
1
ZD4
J47
J48
Q1
J49
J50
R25
R26
R27
R28
R29
R
T-SNR
OP2
O
X
O
X
DISPENSER
DISPENSER LESS
NOM, ISO
O
THERS
OP1
IC8
D22
D21
R14
R
Y13
DSP
LAMP
VA
LV
E
H/BAR
HTR
SLND
DISP
J33
CR1
J32
R
Y10
RY
9
RY
8
RY
7
RY
6
VA
2
RY
5
RY
4
R
Y14
RY
1
RY
3
RY
2
CON1
FUSE1
FUSE2
L1
CM1
L2
J55
R4
D4
R2
F1
R1
CE1
R3
CM3
TRANS
CC4
CC3
CC1
J01
J02
J03
J41
J42
RR2
RR1
J09
J10
J11
J12
RD1
RIM1
R17
RCF1
RCR1
RF1
R44
CC18
CC17
CC14
CC15
CC25
R43
R39
CC7
CC6
R40
R54
J21
J22
R48
R55
R45
R41
R50
R52
J23
J24
J25
R36
CE6
R32
J26
R38
J20
R53
J17
R42
J15
R46
J14
R56
J13
J16
J19
J18
CC19
CC30
CC16
CC23
CC24
J52
J53
CC5
R31
R13
J51
CE2
D5
D7
CE4
J40
R49
CM4
IC11
CC21
CC20
CE8
R57
B
UZZER
R58
CE7
J05
J06
J04
CC22
CC28
CON7
F-SNR
D-SNR
FD/SW
J43
CON9
ICE/M
M
OTO
R
ICE/M
SNR
ST
OP
S/W
TEST
S/W
H/IC
5V
R51
10
CC29
R1-SNR
R2-SNR
RD/SW
STEP MO
TO
R
D
AMP
HTR
CON8
J44
1
1
12
IC10
R37
R18
1
CC27
R59
J07
J54
60
55
50
45
40
35
R47
J45
J46
J28
SW1
CC26
J08
Q5
Q4
CE3
IC3
R8
R7
D6
IC2
R6
D10
D9
D23
D11
R9
J39
J29
J38
IC7
D13
D12
J60
CC13
J27
CE5
IC6
IC5
D8
R5
ZD1
D3
CM2
D1
D2
J34
TAB1
TAB2
VA
1
J35
J56
COM(YELLO
W)
CON2
N-OPEN
COM(YELLO
W)
HTR-DEFR
OST
COMP/F
AN-COOL
N-CLOSE
CON4
CON3
R-LAMP
ICE
SLND
GEAR/MTR
FAN-STD
FAN-HGH
W/T
-HTR
W
ATER
VA
LV
E
R
Y12
CON5
IC9
CC11
R16
CC10
OSC1
R15
30
25
20
S/W2
D16
D14
D17
D18
D19
D20
J31
R
Y11
D15
15
10
J37
R12
CC9
R35
R34
R33
R22
JCR1
JCR2
JCR3
JCR4
R21
R20
R19
R24
R23
R30
RT1
J30
CC12
OP1
OP2
5
IC1
Q2
Q3
2-2. Control of Variable Speed Fan in the Refrigerator Compartment
1. Fan motor in the freezer compartment shall change from standard to high speed rpm in order to increase cooling speed
and load corresponding speed.
2. High speed rpm is only used for the initial power application and load corresponding operation. But standard rpm is
used in the general working conditions.
3. Fan motor in the freezer compartment operates normally when freezer, refrigerator, or home bar door opens and fan
motor in the freezer compartment operates (the speed changes from high to standard rpm if fan motor operates at high
speed rpm). But fan motor in the freezer compartment stops when refrigerator or home bar door is open and refrigerator
compartment door is closed.
speed rpm). But fan motor in the freezer compartment stops when refrigerator or home bar door is open and refrigerator
compartment door is closed.
2-3. Door Opening Alarm
1. Buzzer warns when freezer, refrigerator, or home bar door is kept open for more than 1 minute.
2. Buzzer warns 3 times at 0.5 second interval and then 3 times at 0.5 second on and off in every 30 seconds if door is kept
open for more than 1 minute.
3. Warning is released when freezer, refrigerator, or home bar door is closed during door opening alarm.
2-4 Button Selection Buzzer Sound
1. “Bell” sounds when button on the front display is pressed.
2-5. Forced Start, Forced Defrost Buzzer Warning
1. When test button in the main PWB is pressed, “beep” sounds.
2. When forced start is selected, warning sounds three times for 0.2 second on and 1.8 seconds off.
3. When forced defrost is selected, warning sounds three times in the following cycle: 0.2 second on and 0.2 second off, 0.2
second on and 0.2 second off, and 0.2 second on and 1.0 second off.
2-6. Functions of Defrost
1. Defrost starts whenever the compressor operation time accumulates to seven to seven and a half hours.
2. Defrost starts whenever the compressor operation time accumulates to four to four and a half hours if power is initially
applied (or reapplied after power cut).
3. Defrost completes when the temperature of defrost sensor reaches at 5
°
C. Faulty defrost is indicated if the defrost
sensor does not reach at 5
°
C after 2 hours of defrosting.
4. Defrost does not work when defrost sensor is out of order (wire cut or short-circuit).
MICOM FUNCTION
- 26 -
Closed
Open
Closed
Open
3Times
3Times
3Times
3Times
Closed
Within one minute
one minute
30
Seconds
30
Seconds
30
Seconds
Freezer,
Refrigerator,
or
Home Bar Door
Buzzer
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