LG GB7143**AV Series User manual

CAUTION
BEFORE SERVICING THE UNIT, READ THE "SAFETY
PRECAUTIONS" IN THIS MANUAL.
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MODEL : COLOR :
REFRIGERATOR
SERVICE MANUAL
Ref. No.
GB7143**GZ
GB7143**HZ
Ref. No.
GB7143**RZ
GB7138**XZ
Ref. No.
GB7143**RZ
GB7138**XZ
Ref. No.
GB7143**AV
GB7143**BV

- 2 -
CONTENTS
SAFETY PRECAUTIONS ....................................................................................................................................................... 2
SERVICING PRECAUTIONS ...................................................................................................................................................3
SPECIFICATIONS ................................................................................................................ ................................................4-5
PARTS IDENTIFICATION .....................................................................................................................................................6-9
INSTRUCTIONS FOR REVERSING DOOR SWING ........................................................................................................10-12
DISASSEMBLY .................................................................................................................................................................13-15
DOOR ................................................................................................................................................................................13
DOOR SWITCH .................................................................................................................................................................13
REFRIGERATOR ROOM LAMP ........................................................................................................................................13
FAN AND FAN MOTOR .....................................................................................................................................................14
DEFROST CONTROL ASSEMBLY ...................................................................................................................................14
FRIDGE HEATER, SHEATH .............................................................................................................................................15
FREEZER HEATER, SHEATH ..........................................................................................................................................15
CASE ASSEMBLY, PUMP DISASSEMBLY ......................................................................................................................16
COMPRESSOR .................................................................................................................................................................17-22
INVERTER LINEAR COMPRESSOR ...........................................................................................................................17-22
HEAVY REPAIR METHOD OF REFRIGERATOR BY APPLICATION OF REFRIGERANT ................................................23
OUTLINE ............................................................................................................................................................................23
HEAVY REPAIR SVC METHOD ..................................................................................................................................24-29
CIRCUIT DIAGRAM ...............................................................................................................................................................30
TROUBLESHOOTING (MECHANICAl PART) .................................................................................................................31-35
ANOTHER ELECTRIC COMPONENTS ............................................................................................................................31
SERVICE DIAGNOSIS CHART .........................................................................................................................................32
REFRIGERATING CYCLE ...........................................................................................................................................33-35
MICOM FUNCTION & PCB CIRCUIT EXPLANATION ....................................................................................................36-43
MICOM ERROR CODE ..........................................................................................................................................................43
PCB PICTURE ..................................................................................................................................................................44-45
TROUBLESHOOTING WITH ERROR DISPLAY .............................................................................................................46-56
TROUBLESHOOTING WITHOUT ERROR DISPLAY ......................................................................................................57-65
REFERENCE ..................................................................................................................... ...............................................66-70
EXPLODED VIEW &REPLACEMENT PARTS LIST ........................................................................................................71-83
SAFETY PRECAUTIONS
Please read the following instructions before servicing your
refrigerator.
1. Check the set for electric losses.
2. Unplug prior to servcing to prevent electric shock.
3. Whenever testing with power on, wear rubber gloves to
prevent electric shock.
4. If you use any kind of appliance, check regular current,
voltage and capacity.
5. Don't touch metal products in the freezer with wet
hands. This may cause frostbite.
6. Prevent water from following onto electric elements in
the mechanical parts.
7. When standing up after having checked the lower
section of the refrigerator with the upper door open,
move with care to avoid hitting the upper door.
8. When tilting the set, remove any materials on the set,
especially the thin plates(ex. Glass shelf or books.)
9. When servicing the evaporator, wear cotton gloves.
This is to prevent injuries from the sharp evaporator fins.
10.Leave the disassembly of the refrigerating cycle to a
specialized service center. The gas inside the circuit
may pollute the environment.
11.When you discharge the refrigerant, wear the protective
safety glasses or goggle for eye safety.
12.When you repair the cycle system in refrigerator, the
work area is well ventilated.
Especially if the refrigerant is R600a, there are no fire or
heat sources. (No smoking)

- 3 -
SERVICING PRECAUTIONS
Features of refrigerant (R600a)
•Achromatic and odor less gas.
•Flammable gas and the ignition (explosion) at 494°C.
•Upper/lower explosion limit: 1.8%~8.4%/Vol.
Features of the R600a refrigerator
•Charging of 60% refrigerant compared with a R134a model.
•The suction pressure is below 1bar (abs) during the operation.
•Because of its low suction pressure, the external air may flow
in the cycle system when the refrigerant leak, and it causes
malfunction in the compressor.
•The displacement of compressor using R600a must be at
least 1.7 times larger than that of R134a.
•Any type of dryer is applicable (XH-5, 7, 9).
•The EVAPORATOR or any other cycle part that has welding
joint is hidden in the foam. (If not hidden inside, the whole
electric parts must be tested with the LEAKAGE TEST
according to the IEC Standard.)
•The compressor has label of the refrigerant R600a.
•Only the SVC man must have an access to the system.
After the refrigerant (R600a) is completely discharged, repair
any defective parts and replace the dryer. At any case you
must use the LOKRING for connecting or replacing any part in
the cycle (No Fire, No Welding). Connect the Schrader valve
to pump with the coupler. And then turn the pump on for
vacuum state (Figure 3). Let the pump run until the low-
pressure gauge indicates the vacuum (gauge pressure 0,
absolute pressure -1atm or -760mmHg). Recommended
vacuum time is 30 min. Charge the N2gas in order to check for
leakage from welding points and the LOKRING. If leakages
are found, repair the defects and repeat the vacuum process.
After the system is completely vacuumed, fill it with the
refrigerant R600a up to what has been specified at your
refrigerator Name Plate. The amount of refrigerant (R600a)
must be precisely measured within the error of ±2g by an
electron scale (Figure 4).
If you use the manifold connected with both the refrigerant
(R600a) cylinder and the vacuum pump simultaneously, make
sure the pump valve is closed (Figure 5).
Connect the charging hose (that is connected to the
refrigerant (R600a) cylinder) to the Schrader valve installed
on the service tube. Then, charge the refrigerant (R600a) by
controlling the Throttle valve. When you do so, do not fully
open the Throttle valve because it may make damage to the
compressor. Gradually charge the refrigerant (R600a) by
changing open and close the Throttle Valve (5g at each time).
The charging hose must use a one-way valve to prevent the
refrigerant refluence. Close the Schrader valve cap after the
refrigerant (R600a) is completely recharged.
After you completely recharge the refrigerant (R600a),
perform the leakage test by using a portable leakage detector
or soapy water. Test the low pressure (suction) parts in
compressor off time and high pressure parts in compressor
on time. If the leakages are found, restart from the refrigerant
(R600a) discharging process and repairs defects of leaks.
After the leakage test, check the temperature of each parts of
the cycle. Check with hands if the CONDENSER and the
case (HOT-LINE pipe) that is contacted to the door gasket
are warm. Confirm that frost is uniform distributed on the
surface of the EVAPORATOR.
Installation place
• Must be well ventilated.
• Must be 20 m3or larger.
• Must be no-smoking area.
• No ignitable factors must be present.
Utilities
• Refrigerant cylinder (MAX NET 300g)
• Manometer
• Vacuum pump (600 /min)
• Piercing Clamp
• Quick coupler
• Hoses (5m-1EA, 1m-3EA)
• LOKRING
• Portable Leakage detector (3g/year )
• Nitrogen cylinder (for leakage test)
• Concentration gauge
Make sure before Servicing
•Refrigerant
Confirm the refrigerant by checking Name Plate and the label
on the compressor, after opening the COVER ASSEMBLY,
BACK-M/C.
•If the refrigerant is R600a, you must not weld or apply a heat
source.
Air Recharging in Compressor
Before refilling the refrigerant, you must perform the test
according to Chapter 5 (TROUBLESHOOTING CHART). When
the defects are found, you must discharge the residual
refrigerant (R600a) in the outdoor. For discharging the
refrigerant R600a, break the narrow portion of tube extension
by hand or with a pipe cutter as shown in Figure 1. Leave it for
30min in outside to stabilize the pressure with ambient. Then,
check the pressure by piercing the dryer part with piercing
pliers. If the refrigerant is not completely discharged, let the
refrigerator alone for more 30min in outside.
Attach the service tube installed with a Schrader valve (one-
way valve) by using the LOKRING (Figure 2). Then, connect
the Schrader valve (one-way valve) to the pump that is
connected to the discharging hose leading to the outside.
When discharging the residual refrigerant, repeat 3 cycle that
includes 3min of the pump running->pump off->30sec of the
compressor running.
Figure 1 Figure 2
Figure 3
Figure 4
Figure 5

- 4 -
SPECIFICATIONS
1. Ref. No: GB7143*****
NET WEIGHT
COOLING SYSTEM
TEMPERATURE CONTROL
REFRIGERANT WEIGHT
COMPRESSOR
EVAPORATOR
CONDENSER
DIMENSIONS (mm)
DEFROSTING SYSTEM
DEFROSTING DEVICE
REFRIGERATOR
COMPARTMENT
DOOR BASKET
FREEZER
COMPARTMENT
LUBRICATION OIL
ITEMS
595(W) X 2010(H) X 671(D)
595(W) X 1850(H) X 671(D)
-
Fan Cooling
Micom Control
Full Automatic
Heater Defrost
Heater, Sheath
Heater, L-Cord
R600a
FREOL 60MT 310 cc
FREOL 55MT 180 cc
PTC Starting Type
Pin Tube Type
Wire Condenser
Removable Glass Shelf
Bottle Rack (1EA)
Vita, LED(1EA)
Cover, TV (1EA)
Rail (2EA)
Magic Crisper (1EA)
Vegetable Drawer (1EA)
OPTI-Zone (1EA)
Egg Tray
Dairy Corner
Basket Door
Basket
Water Tank
Tray Drawer (3EA)
Ice bin (1EA)
Twist Ice Maker Kit (1EA)
Auto Ice Maker
Guide, Rail (1EA)
Wire Shelf (2EA)
73g
-
3EA
-
GB7143**(A/B)V
73g
-
3EA
-
GB7143**(G/H)Z
71g
-
3EA
-
GB7143**(G/H)W

- 5 -
2. Ref. No: GB71(43/38)*****
NET WEIGHT
COOLING SYSTEM
TEMPERATURE CONTROL
REFRIGERANT WEIGHT
COMPRESSOR
EVAPORATOR
CONDENSER
DIMENSIONS (mm)
DEFROSTING SYSTEM
DEFROSTING DEVICE
REFRIGERATOR
COMPARTMENT
DOOR BASKET
FREEZER
COMPARTMENT
LUBRICATION OIL
ITEMS
595(W) X 2010(H) X 671(D)
595(W) X 1850(H) X 671(D)
-
Fan Cooling
Micom Control
Full Automatic
Heater Defrost
Heater, Sheath
Heater, L-Cord
R600a
FREOL 60MT 310 cc
FREOL 55MT 180 cc
PTC Starting Type
Pin Tube Type
Wire Condenser
Removable Glass Shelf
Bottle Rack (1EA)
Vita, LED(1EA)
Cover, TV (1EA)
Rail (2EA)
Magic Crisper (1EA)
Vegetable Drawer (1EA)
OPTI-Zone (1EA)
Egg Tray
Dairy Corner
Basket Door
Basket
Water Tank
Tray Drawer (3EA)
Ice bin (1EA)
Twist Ice Maker Kit (1EA)
Auto Ice Maker
Guide, Rail (1EA)
Wire Shelf (2EA)
71g
-
3EA or 2EA
-
-
-
2EA
-
-
-
-
GB71(43/38)**(R/X)W
73g
-
3EA or 2EA
-
-
-
2EA
-
-
-
-
GB71(43/38)**(R/X)Z
-
71g
-
3EA or 2EA
-
-
-
2EA
-
-
-
GB71(43/38)**(P/V)W