LG GR-B207WVQ.CSWQAGE User manual

CAUTION
PLEASE READ CAREFULLY THE SAFETY PRECAUTIONS OF THIS BOOK
BEFORE CHECKING OR OPERATING THE REFRIGERATOR .
REFRIGERATOR
SERVICE MANUAL
http://biz.lgservice.com
MODEL:GR-B207WVQ.CSWQAGE Color:Super White

WARNINGS AND PRECAUTIONS FOR SAFETY ........................................................................................... ..................... 3
SPECIFICATIONS................................................................................................................................................................... 4
PARTS IDENTIFICATION ........................................................................................................................................................5
HOW TO INSTALL THE REFRIGER ATOR .......................................................................................................................... 6
HOW TO ADJUST DOOR HEIGHT OF THE REFRIGERATOR ........................................................................................ 6
HOW TO INSTALL WATER PIPE........................................................................................................................................ 6
HOW TO CONTROL THE AMOUNT OF WATER SUPPLIED TO THE ICEMAKER ......................................................... 7
MICOM FUNCTION .............................................................................................................................................................. 8-12
EXPLATION FOR MICOM CIRCUIT..................................................................................................................................... 13
EXPLANATION FOR PWB CIRCUIT ................................................................................................................................. 13
COMPENSATION CIRCUIT FOR WEAK-COLD, OVER-COLD AT FREEZING ROOM.................................................... 14
PWB PARTS DRAWING AND LIST ................................................................................................................................... 35
PWB CIRCUIT DIAGRAM .................................................................................................................................................. 25
CIRCUIT................................................................................................................................................................................ 26
TROUBLE DIAGNOSI S ........................................................................................................................................................ 27
TROUBLE SHOOTING ...................................................................................................................................................... 37
FAULTS ............................................................................................................................................................................ 45
COOLING CYCLE HEAVY REPAIR ................................................................................................................................. 57
HOW TO DEAL WITH CLAIMS........................................................................................................................................ 65
HOW TO DISASSEMBLE AND ASSEMBL E ..................................................................................................................... 66
DOOR............................................................................................................................................................................... 66
HANDLE ........................................................................................................................................................................... 67
SHROUD, GRILLE FAN ................................................................................................................................................... 67
EXPLODED VIEW .............................................................................................................................................................. 68-72
CONTENTS
- 2 -

Please observe the following safety precautions in order to
use safely and correctly the refrigerator and to prevent
accident and danger during repair.
1. Be care of an electric shock. Disconnect power cord
from wall outlet and wait for more than three minutes
before replacing PWB parts. Shut off the power
whenever replacing and repairing electric components.
2. When connecting power cord, please wait for more than
five minutes after power cord was disconnected from the
wall outlet.
3. Please check if the power plug is pressed down by the
refrigerator against the wall. If the power plug was
damaged, it may cause fire or electric shock.
4. If the wall outlet is over loaded, it may cause fire. Please
use its own individual electrical outlet for the refrigerator.
5. Please make sure the outlet is properly earthed,
particularly in wet or damp area.
6. Use standard electrical components when replacing
them.
7. Make sure the hook is correctly engaged.
Remove dust and foreign materials from the housing
and connecting parts.
8. Do not fray, damage, machine, heavily bend, pull out,
or twist the power cord.
9. Please check the evidence of moisture intrusion in the
electrical components. Replace the parts or mask it
with insulation tapes if moisture intrusion was
confirmed.
10. Do not touch the icemaker with hands or tools to
confirm the operation of geared motor.
11. Do not let the customers repair, disassemble, and
reconstruct the refrigerator for themselves. It may
cause accident, electric shock, or fire.
12. Do not store flammable materials such as ether,
benzene, alcohol, chemicals, gas, or medicine in the
refrigerator.
13. Do not put flower vase, cup, cosmetics, chemicals,
etc., or container with full of water on the top of the
refrigerator.
14. Do not put glass bottles with full of water into the
freezer. The contents shall freeze and break the glass
bottles.
15. When you scrap the refrigerator, please disconnect the
door gasket first and scrap it where children are not
accessible.
WARNINGS AND PRECAUTIONS FOR SAFETY
- 3 -

SPECIFICATIONS
- 4 -
ITEMS SPECIFICATIONS
DIMENSIONS (mm) 894(W) X 725(D) X 1753(H)
NET WEIGHT (kg) 110
COOLING SYSTEM Fan Cooling
TEMPERATURE CONTROL Micom Control
DEFROSTING SYSTEM Full Automatic
Heater Defrost
INSULATION Cyclo-Pentane
COMPRESSOR P.T.C. Starting Type
EVAPORATOR Fin Tube Type
CONDENSER Wire Condenser
REFRIGERANT R134a (180g)
LUBRICATING OIL FREOL @10G (310 cc)
DRIER ID 0.83
ITEMS SPECIFICATIONS
CAPILLARY TUBE MOLECULAR SIEVE XH-7
FIRST DEFROST 4 - 5 Hours
DEFROST CYCLE 13 - 15 Hours
DEFROSTING DEVICE Heater, Sheath
ANTI-FREEZING HEATER Damper Heater
FREEZER LAMP 40W (1 EA)
REFRIGERATOR LAMP 40W (1 EA)
<Front View> <Plane View>
3. Model spec.
25
7
3571
4

PARTS IDENTIFICATION
- 5-
Frame Display
Cover PWB
2. Ref No.
Conversion switch
(Meats/Vegetables)

1. How to Adjust Door Height of Refrigerator
Make the refrigerator level first. (If the refrigerator is not installed
on the flat floor, the height of freezer and refrigerator door may
not be the same.
1. If the height of freezer door is lower than that of
refrigerator compartment :
2. If the height of freezer door is higher than that of
refrigerator compartment :
Insert a driver into the groove of adjusting screw
and rotate driver in arrow direction (clockwise) until the
refrigerator becomes horizontal.
Insert a driver into the groove of adjusting screw
and rotate driver in arrow direction (clockwise) until the
refrigerator becomes horizontal.
HOW TO INSTALL REFRIGER ATOR
- 6-
1
1
2
2
Adjusting
Adjusting
Driver
Driver
Even if the height can not be aligned by
using the height adjustment screw,insert
the transparent sheet supplied with the
product.
Bottom bracket
Transparent sheet
Bottom hinge
Separate the door with the lower height,
use the (+) type screwdriver to unscrew
the screw at the botton hinge as shown
at figure , insert the transparent sheet
between the bottom hinge and the bottom
bracket,and then fix it with the screw as
shown at figure .
Insert more transparent sheets enough to
align the height.(4 sheets are supplied in
total.)

Install Water Filter (Applicable to some models only)
Before Installing water filter
1. Before installing the filter, take out the top shelf of the
refrigerator after tilting it to the direction ( ) and lifting it
to the direction ( ) and move it to the lower part.
2. Lamp in refrigerator compartment
Installing water filter
1. Initial installation of water filter
Remove the filter substitute cap by turning it
counterclockwise ( ) by 90 degrees and pulling it down.
Note : Keep it safe to use it later when you do not use the
filter.
Remove the red cap from the filter and attach the
sticker. Insert the upper part of the filter ( ) after
aligning with the guideline marked on the control box,
and fasten it by turning it clockwise by 90 degrees.
Note : Check that the guideline and the fastening
indication line are aligned.
2. Replacement of water filter
While holding the lower part of the filter, turn it
counterclockwise ( ) by 90 degrees and pull it down.
Note : Check that the guideline and the loosening
indication line are aligned.
After installing water filter
Reassemble the lamp cover and the top shelf of the
refrigerator. To place the top shelf of the refrigerator, raise
the front part of the shelf a bit so that the hook of the shelf
is fit into the groove.
In order to clean the water filter system, drain water for
about 3 min.
Note : Then open the door of the refrigerator and check for
water droppings on the shelf under the filter.
Control box
Aligning with the guide line
and the fastening indication line
Aligning with the guide line
and the loosening indication line
Control box
Separation
of red cap
Adhesion
sticker
Substitute
cap
HOW TO INSTALL REFRIGER ATOR
- 7-
Insert the tool into the marked area ( ) and
push the tool to disconnect.
Use the tool with the flat tip such as ( - ) screw
driver.
Turn the bulb counterclockwise. Max. 40 W
bulb for refrigerator is used and can be
purchased at a service center.
3
3

1. Monitor Panel
MICOM FUNCTION
- 8-
2. Description of Function
2-1. Funnction of Temperature Selection
* The temperature can vary ±3 °C depending on the load condition. *( ) : 127V/60Hz, 110~115V/60Hz, 115V/60Hz Rating ONLY.
*< > : TAIBEI
1. When power is initially applied or reapplied after power cut, “Medium” is automatically selected.
2. When the temperature selection switch in the freezer and refrigerator compartments is pressed, the light is on in the
following sequence:
"Middle" "Middle Strong" "Strong" "Weak" "Middle Weak"
3. The temperature setting condition of freezer and refrigerator compartments shall not be indicate in the standard model
when refrigerator or home bar door is closed.
Divisio n Power Initial ly On 1st Pres s 2nd Pres s 3th Pres s 4th Press
- 19 °C 3 °C - 22 °C 2 °C - 23 °C 0 °C - 15 °C 6 °C - 17 °C 4 °C
Change of
IndicationLamp
Temperature
Control
Middle Middle Strong Strong Weak Middle Weak
-19 °C
(-18 °C)
<-19 °C>
3 °C
<2 °C>
1.5 °C
<1 °C>
0 °C
<0 °C>
6 °C
<4.5 °C>
4.5 °C
<3 °C>
-21 °C
(-21 °C)
<-21 °C>
-23 °C
(-22 °C)
<-22 °C>
-15 °C
<-16.5 °C>
-17 °C
<-18 °C>
Freezer
Control
Refrigeration
Control
1. 88 LED
Function display board
FREEZER
Temperature adjustment botton
for freezer compartment
Temperature adjustment botton
for refrigerator compartment
Express freezer Lock button
EXPRESS FRZ.
FRZ
REFRIGERATOR
CHILD LOCK
3secs

2-2. Control of variable type of freezing room fan
1. To increase cooling speed and load response speed, MICOM variably controls freezing room fan motor at the high speed
of RPM and standard RPM.
2. MICOM only operates in the input of initial power or special freezing operation or load response operation for the high
speed of RPM and operates in the standard RPM in other general operation.
3. If opening doors of freezing / cold storage room or home bar while fan motor in the freezing room operates, the freezing
room fan motor normally operates (If being operated in the high speed of RPM, it converts operation to the standard
RPM). However, if opening doors of freezing room or home bar, the freezing room fan motor stops.
4. As for monitoring of BLDC fan motor error in the freezing room, MICOM immediately stops the fan motor by determining
that the BLDC fan motor is locked or poor if there would be position signal for more than 65 seconds at the BLDC motor.
Then it displays failure (refer to failure diagnosis function table) at the display part of refrigerator, performs re-operation in
the cycle of 30 minutes. If normal operation is performed, poor status is released and refrigerator returns to the initial
status (reset).
2-3. Control of M/C room fan motor
1. The M/C room fan motor performs ON/OFF control by linking with the COMP.
2. It controls at the single RPM without varying RPM.
3. Failure sensing method is same as in fan motor of freezing fan motor (refer to failure diagnosis function table for failure
display).
2-4. Door opening alarm
1. Buzzer generates alarm sound if doors are not closed even when more than a minute consecutively has passed with
doors of freezing / cold storage room or home bar opened.
2. Buzzer rings three times in the interval of 0.5 second after the first one-minute has passed after doors are opened and
then repeats three times of On/Off alarm in the cycle of every 30 seconds.
3. If all the doors of freezing / cold storage room or home bar are closed during door open alarm, alarm is immediately
released.
2-5. Ringing of button selection buzzer
1. If pressing the front display button, “Ding ~ “sound rings.
2-6. Ringing of compulsory operation, compulsory frost removal buzzer
1. If pressing the test button in the main PCB, “Phi ~ “sound rings.
2. In selecting compulsory operation, alarm sound is repeated and completed in the cycle of On for 0.2 second and Off for
1.8 second three times.
3. In selecting compulsory frost removal, alarm sound is repeated and completed in the cycle of On for 0.2 second , Off for
0.2 second, On for 0.2 second and Off for 1.4 second three times.
MICOM FUNCTION
- 9-
Doors of freezing /
cold storage room
or home bar
BUZZER
Closing
Opening
Within
a minute
A minute
30
seconds
30
seconds
30
seconds
Opening Closing Closing
3 Times 3 Times 3 Times 3 Times

2-7. Frost removal function
1. Frost removal is performed whenever total operation time of compressor becomes 7 ~ 7.5 hour.
2. In providing initial power (or returning power failure), frost removal starts whenever total operation time of compressor
becomes 4 ~ 4.5 hour.
3. Frost removal is completed if temperature of a frost removal sensor becomes more than 5°C after starting frost removal.
Poor frost removal is not displaced if it does not arrive at 5°C even if two hours have passed after starting frost removal.
4. No removal is done if frost removal sensor becomes poor (snapping or short-circuit).
2-8. Sequential operation of built-in product
Built-in products such as compressor, frost removal heater, freezing room fan, Cooling Fan and step motor damper are
sequentially operated as follows for preventing noise and part damage occurred due to simultaneous operation of a lot of
parts in applying initial power and completing test.
MICOM FUNCTION
- 10-
Function Load Operation Sequence Remark
r
ewo
plait
inIg
niylpp
anI E
DOM
T
SET
When temperature
of a frost removal
sensor becomes
more than 45°C
(In purchase,
movement)
If error occurs
during operation,
initial operation is
not done.
If pressing switch
once more in the
test mode 2 or
temperature of a
frost removal
sensor is more
than 5°C, it
immediately
returns to the test
mode for initial
operation
(COMP operates
after 7 minutes).
When
temperature of a
frost removal
sensor becomes
less than 45°C
(In power failure,
service)
Test mode 1
(Compulsory
function)
Test mode 1
(Compulsory
function)
Test mode 2
(Compulsory frost
removal)
POWER
ON
COMP
ON
COMP
ON
F-FAN
&
C-FAN
ON
F-FAN
&
C-FAN
ON
F-FAN
&
C-FAN
ON
F-FAN
&
C-FAN
OFF
STEP
MOTOR
DAMPER
ON
STEP
MOTOR
DAMPER
ON
STEP
MOTOR
DAMPER
OPEN
STEP
MOTOR
DAMPER
CLOSE
HOME
BAR
HEATER
ON
POWER
ON
FROST
REMOVAL
HEATER
ON
HOME
BAR/
PIPE
HEATER
OFF
HOME
BAR/
PIPE
HEATER
ON
TEST
S/W
(Press
Once)
COMP
ON
TEST
S/W
(Press
3 times)
0.5
sec.
0.3
sec.
0.3
sec.
0.3
sec.
0.5
sec.
8
sec.
0.3
sec.
5
sec.
FROST
REMOVAL
HEATER
OFF
FROST
REMOVAL
HEATER
ON
27
sec.
0.3
sec.
0.3
sec.
0.3
sec.
0.3
sec.
0.3
sec.
0.3
sec.
0.3
sec.
5.6
sec.
OTHER
LOAD
OFF
F-FAN
&
C-FAN
ON
F-FAN
&
C-FAN
OFF
STEP
MOTOR
DAMPER
OPEN
TEST
S/W
(Press
2 times)
COMP
0.3
sec.
0.3
sec.
0.3
sec.
OFF

2-9. Function of Trouble Diagnosis(88-LED)
1. Failure diagnosis function is function to facilitate service when nonconforming matters affecting performance of product
during use of product.
2. In occurrence of failure, pressing the function adjustment button does not perform function and only alarm sound (“Ding~”) rings.
3. If nonconforming matters occurred are released during display of failure code, MICOM returns to the original state (Reset).
4. Failure code is displayed on the display part of setting temperature for the freezing room and the display part of setting
temperature for the cold storage room of LED, which are placed at the display part of a refrigerator. All the LED graphics
other than a failure code are turned off.
In display of the failure mode, all LEDs of setting temperature for freezing/ setting temperature for cold storage are turned
off (excluding Note1 and Note2).
MICOM FUNCTION
- 11 -
: Normal Operation
1
2
3
4
5
6
7
8
9
10
11
Er FS
Er rS
Setting temperature
display (Note 2)
Er dS
Er dH
Er FF
Er CF
Er CO
Setting temperature
display (Note 1)
Setting temperature
display (Note 2)
Setting temperature
display (Note 2)
Failure code display part
Setting
temperature
for freezing
Setting
temperature for
cold storage
No. Item Contents of failure
Freezer
Fan
Compr essor
Stepping
motor damper
Defros t
Heater
M/C roo m
Fan
Product operation status in failure
Failure of freezer
sensor
Failure of refrigerator
sensor 1
Failure of refrigerator
sensor 2
Failure of frost
removal sensor
Poor of frost
removal
Failure of BLDC FAN
at freezing room
Failure of BLDC FAN
at machine room
Failure of
Communication
Failure of
Outside Sensor
Failure of ice
removal sensor
Failure of ice
maker unit
Snapping or short-circuit of
freezer sensor
Snapping or short-circuit of
refrigerator sensor 1
Snapping or short-circuit of
refrigerator sensor 2
Snapping or short-circuit of frost
removal sensor
Snapping of frost removal heater
or temperature fuse, pull-out of
connector (indicated minimum 4
hours after failure occurs)
Poor motor, hooking of wires to
fan. Contact of structures to Fan.
Snapping or short-circuit of L/wire
(if there is no fan motor signal for
more than 115 seconds in
operation of fan motor
Connection between main PCB
and display PCB. Snapping or
short-circuit of L/wire.
Transmission between main PCB
and display PCB. Poor TR and
receiving part.
Snapping or short-circuit of outside
temperature perceiving sensor
Snapping or short-circuit of ice-
making sensor
Poor motor or Hall IC within ice-maker
unit. Snapping or short-circuit of
L/Wire. Poor main PCB drive circuit.
Standard
RPM
Standard
RPM
Standard
RPM
Standard
RPM
Standard
RPM
OFF
Standard
RPM
Standard
RPM
OFF
ON for 15minutes
OFF for 15minutes
No frost
removal
Open for 10munutes,
closing for 15 minutes
Failure Code Display Part
BAISE
FRZ TEMP
EXPRESS FRZ CHILD LOCK
REF TEMP

Note1) In error of outside sensor, setting temperature for freezing/ cold storage is normally displayed and indicated “Er” on
the outside temperature display part (normally displayed except for the outside temperature display part).
Note2) Nonconforming contents of poor R2 sensor, ice-making sensor and ice-making kit are displayed in LED check, not
indicated on the failure display part (when pressing freezing temperature adjustment button and special freezing
button for a second or more).
HOME BAR SENSOR
A
A
B
B
C
C
D
D
2-10. Test Function
1. The purpose of test function is to check function of the PWB and product and to search for the failure part at the failure
status.
2. Test button is placed on the main PCB of refrigerator (test switch), and the test mode will be finished after maximum 2
hours irrespective of test mode and then is reset to the normal status.
3. Function adjustment button is not perceived during performance of test mode but only warning sounds ring.
4. In finishing test mode, always pull the power cord out and then plug-in it again for the normal state.
5. If nonconforming contents such as sensor failure are found during performance of test mode, release the test mode and
display the failure code.
6. Even if pressing the test button during failure code display, test mode will not be performed.
Test 1
Test 3
Test 2
Normal
Status
Mode Manipulation Content Remarks
Press test button once
(freezing force mode)
Press test button once at
the test mode 2 status
(compulsory frost removal
mode)
Press test button once at
the test mode 1 status
(compulsory frost removal
mode)
Press test button once at
the test mode 3 status
(freezing force mode)
1. Continuous operation of compressor
2. Continuous operation of freezing room fan
(high speed RPM) and M/C room fan
3. Frost removal heater OFF
4. Full opening status (baffle opened) status of
electronic step motor damper
5. All display LED graphics - ON.
1. Compressor OFF
2. Freezing room fan and M/C room fan is
turned off.
3. Frost removal heater ON
4. Full closing status (baffle closed) status of
electronic step motor damper
5. All display LED graphics - OFF
(88LED: Except for (A)22 (B)22 LEDs
Bar, Dot LED: Except for only middle Notch
Bar Graphics)
1. Compressor OFF
2. Freezing room fan(high speed RPM) and
M/C room fan is turned off.
2. Freezing room fan(normal speed RPM) and
M/C room fan is turned off.
3. Frost removal heater OFF
4. Full closing status (baffle closed) status of
electronic step motor damper
5. All display LED graphics - OFF
(88LED: Except for (A)22 (B)22 LEDs
Bar, Dot LED: Except for only middle Notch
Bar Graphics)
Return to the initial status.
Compulsory function
Compulsory function
Check freezing room fan
Compressor is operated
after 7 minutes.
MICOM FUNCTION
- 12 -
•
Return to the normal
mode when the defrost
sensor is above +5
•
°C

1. Explanation for PWB circuit
1-1. Power circuit
Voltage of every part is as follows:
Part VA1 CM1 CM2 CE2 CE4
Voltage 220 Vac 14 Vdc 17 Vdc 12 Vdc
EXPLATION FOR MICOM CIRCUIT
- 14 -
5Vdc
1-2. Oscillation circuit
Oscillation circuit is a circuit with the purpose of generating
basic time for clock occurrence for synchronization and time
calculation in relation with information transmission/reception
of inside elements of IC1 (MICOM). The OSC1 must always
use rated parts since if SPEC is changed,time calculated at
the IC1 may be changed or no operation is done.
1-3. Reset circuit
The reset circuit is circuit allowing various parts such as RAM
inside of MICOM (IC1) to initialize and the whole of function
to start from the initial status, when initial power is input or
when power is applied again to MICOM by a spontaneous
power failure. ‘LOW’ voltage is applied to the reset terminal
of MICOM in the beginning of power supply for a constant
time (10ms). Reset terminal during general operation is 5V
(No MICOM operates in failure of RESET IC).

2) GC-B207W
The fan motor at the freezing room does not stop but operates if opening doors of the freezing room or cold storage room
or the home bar during operation of the fan motor at the freezing room.
(A), (B), (C) and (D) of door switch for the freezing room or cold storage room are connected to the door open sensing
circuit toward both ends of switch to determine door open at MICOM.
Since a door switch of the home bar is connected to door switch (C), (D) of the cold storage room, it senses door opening
if even one of both is opened.
EXPLATION FOR MICOM CIRCUIT
- 14-
Measuring part (IC4)
Status
The circuit has been only applied to voltage except 220v.
ON Within 1 V
OFF 12 V
Type of Load Frost Removal
Heater
R-room
LAMP
Home-bar
Heater
AC Converting
Relay
R-room FAN MOTOR
High speed Normal speed
No.10 No.11 No.12 No.16 No.15 No.13 No.14
COMP

Since door switch sensing switch (A), (B) are a separate switch even if the door switch of the freezing room normally
operates, they may fail to sense door opening in the failure of switch at both ends of (A) and (B) or in failure of the L/wire.
Lamp does at the cold storage room not turn on if the door switch of the cold storage room fails to sense the door open
switch (c ), (d) or the home bar switch(e ), (f).
EXPLATION FOR MICOM CIRCUIT
- 16 -
Closing 5 V ( A - B , C - D . S/W at both ends are at Off status)
Opening 0 V ( A - B , C - D , S/W at both ends are at On status)
Measuring part
IC1 (MICOM) No. 47, 46 Pin
Door of Freezing/Cold Storage Room
CONDITIONS Bell sounds when button on Beep sounds when warning
MEASURING
dosplay is pressed. door opening. OFF
POINTS
IC1 (No. 50 Pin) 0 V
IC1 (No. 50 Pin) 0 V
0.05 s
2.63 kz (DING)
2.63 kz (BEEP) OFF
2.21 kz (DONG)
0.2 s 0.1 s 0.4 s 0.5 s 0.5 s
5 V
0 V
5 V
0 V
5 V
0 V
5 V
0 V
2.Buzzer driving circuit
3.Door opening sensing circuit
, E - F
, E - F

1-5. Switch entry circuit
The following circuits are entry circuits for sensing signal form test S/W, electronic single motor damper reed S/W for
examining refrigerator.
1-6. Option designation circuit (model separation function)
The above circuits are used for designating separation by model as option and notifying it to MICOM. Designation of option
by model and the application standards are as follows:
These circuits are accurately pre-adjusted in shipment from factory and so you must not additionally add or remove
option.
EXPLATION FOR MICOM CIRCUIT
- 17 -
Separatio n Connection Status Application Standard
Connectio OTHER AREA(VOLATILE)
OP1
OUT Domestic
1-7. Stepping motor operation circuit
Connection DISPENSER MODEL
OP2
OUT NON-DISPENSER MODEL
For motor driving method, rotation magnetism is formed at coils wound on each phase of motor and stator and so motor
becomes to rotate if applying “High” signal to the IC6 (TA774AP) at the MICOM PIN 41 and outputting “High”, “Low” signal
by step numbers fixed through MICOM PIN 42 and 43.

Explanation) For driving method of the stepping motor, send signals in the cycle of 3.33 mSEC using terminal of MICOM
PIN 33, 34 and 35 as shown in wave form of the following part.
These signals are output to the output terminal (No.10, 11, 14, 15) via the input terminal (No. 3, 6, 8) of the
IC10 (TA7774F) as IC for motor driving. Output signals allow motor coils wound on each phase of stator to
form rotation magnetic field and the motor to rotate. Inputting as below figure to the input terminal (INA, INB)
as IC (TA7774AF) for motor driving allows motor coils wound on each phase of stator to form rotation
magnetic field and the stepping motor damper to rotate
EXPL A TION FOR MICOM CIRCUIT
- 18-
(Reverse rotation) (Positive rotation)
1-8. Temperature compensation and over-cool/weak- cool compensation circuit
1. Temperature compensation at freezing room, cold storage room
冷藏室温度补偿
冷冻室温度补偿
Freezing room
Temperature
compensation
Temperature
compensation
Refrigerator room
Resistance value
(RC F1）Resistance value
(RC F1）
Remarks
Reference temperature
Warmly
compensate
Coolly
compensate
180 kΩ+5 °C 180 kΩ+2.5 °C
56 kΩ+4 °C 56 kΩ+2.0 °C
33 kΩ+3 °C 33 kΩ+1.5 °C
18 kΩ+2 °C 18 kΩ+1.0 °C
12 kΩ+1 °C 12 kΩ+0.5 °C
10 kΩ0 °C 10 kΩ0 °C
8.2 kΩ-1 °C 8.2 kΩ-0.5 °C
5.6 kΩ-2 °C 5.6 kΩ-1.0 °C
3.3 kΩ-3 °C 3.3 kΩ-1.5 °C
2 kΩ-4 °C 2 kΩ-2.0 °C
470Ω-5 °C 470Ω-2.5 °C
Temperature compensation table by adjustment value (difference value against current temperature)
Ex) If changing compensation resistance at a cold storage room (RCR1) from 10 kΩ(current resistance) to 18 kΩ
(modified resistance), temperature at the cold storage will increase by +1°C.

uTemperature compensation table at the refrigerator room is as follows:
uThis circuit is a circuit to enter the necessary level of temperature compensation for adjusting different temperature every
model at the cold storage room into MICOM.
EXPLATION FOR MICOM CIRCUIT
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470 Ω2 kΩ3.3 kΩ5.6 kΩ8.2 kΩ10 kΩ12 kΩ18 kΩ33 kΩ56 kΩ180 kΩ
No 0.5 °C1°C 1.5 °C2°C 2.5 °C3°C 3.5 °C4°C 4.5 °C5°C
470Ω
change Up Up Up Up Up Up Up Up Up Up
0.5 °C No 0.5 °C1°C 1.5 °C2°C 2.5 °C3°C 3.5 °C4°C 4.5 °C
2 kΩ
Down change Up Up Up Up Up Up Up Up Up
1 °C 0.5 °C No 0.5 °C1°C 1.5 °C2°C 2.5 °C3°C 3.5 °C4°C
3.3 kΩ
Down Down
change Up Up Up Up Up Up Up Up
1.5 °C1°C 0.5 °C No 0.5 °C1°C 1.5 °C2°C 2.5 °C3°C 3.5 °C
5.6 kΩ
Down Down Down change Up Up Up Up Up Up Up
2 °C 1.5 °C1°C 0.5 °No 0.5 °C1°C 1.5 °C2°C 2.5 °C3°C
Rerigerator 8.2 kΩ Down Down Down Drop change Up Up Up Up Up Up
room
2.5 °C2°C 1.5 °C1°C 0.5 °C No 0.5 °C1°C 1.5 °C2°C 2.5 °C
(RCR1) 10 kΩ
Down Down Down Down Down change Up Up Up Up Up
3 °C 2.5 °C2°C 1.5 °C1°C 0.5 °C No 0.5 °C1°C 1.5 °C2°C
12 kΩ
Down Down Down Down Down Down change Up Up Up Up
3.5 °C3°C 2.5 °C2°C 1.5 °C1°C 0.5 °C No 0.5 °C1°C 1.5 °C
18 kΩ
Down Down Down Down Down Down Down change Up Up Up
4 °C 3.5 °C3°C 2.5 °C2°C 1.5 °C1°C 0.5 °C No 0.5 °C1°C
33 kΩ
Down Down Down Down Down Down Down Down
change Up Up
4.5 °C4°C 3.5 °C3°C 2.5 °C2°C 1.5 °C1°C 0.5 °C No 0.5 °C
56 kΩ
Down Down Down Down Down Down Down Down Down change Up
5 °C 4.5 °C4°C 3.5 °C3°C 2.5 °C2°C 1.5 °C1°C 0.5 °CNo
180 kΩ
Down Down Down Down Down Down Down Down Down Down change
Modification
resistance
Current
resistance

1-9 . Compensation circuit for weak-cold, over-cold at freezing room
The above option circuit is a circuit to compensate for temp erature at the cold storage room by simply cutting in service.
Compensation Compensation
for weak-cold for over-cold Temperature compensation value Remarks
JCR3 JCR4 JCR1 JCR2 at cold storage room
0 °C (In shipment from factory)
CUT -1 °C
CUT -1 °C
CUT +1 °C
CUT +1 °C
CUT CUT -2 °C
CUT CUT +2 °C
CUT CUT 0 °C
CUT CUT 0 °C
CUT CUT 0 °C
CUT CUT 0 °C
CUT CUT CUT -1 °C
CUT CUT CUT +1 °C
CUT CUT CUT CUT 0 °C
EXPLATION FOR MICOM CIRCUIT
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Temperature compensation in CUT
JCR1 +1?
JCR2 +1?
+2?
JCR3 -1?
JCR4 -1?
-2?

1-10. Key Button Input and Display Lighting Circuit
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.
EXPLATION FOR MICOM CIRCUIT
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