LG LMX25984ST/01 User manual

REFRIGERATOR
SERVICE MANUAL
CAUTION
BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.
MODEL : LMX25984ST /01
LMX25984WB /01
LMX25984SW /01

ENC(Engineering Change Number)
- 2 -
Base Assembly,Compressor
Cover,PTC
Damper Assembly,Seat
Condenser Assembly,Wire
Door Assembly,Refrigerator(Left)
Door Assembly,Refrigerator(Right)
Door Foam Assembly,Refrigerator
Door Foam Assembly,Refrigerator
Harness Assembly
Harness Assembly
Capacitor,Electric Appliance Film,Radial
PCB Assembly,Sub
PCB Assembly,Main
Case,PCB
Guide,Fan
Tray,Drip
Compresser,Set
315A
304A
312A
323B
230B
230A
231B
231A
303A
619E
410G
500H
500A
413A
319C
319A
300A
Loc No. Part Name
LMX25984 /01

- 3 -
CONTENTS
SAFETY PRECAUTIONS ....................................................................................................................................................... 2
1. SPECIFICATIONS .............................................................................................................................................................. 3
2. PARTS IDENTIFICATION .................................................................................................................................................. 4
3. DISASSEMBLY ............................................................................................................................................................. 5-14
REMOVING AND REPLACING REFRIGERATOR DOORS ............................................................................................... 5
DOOR INSTALLATION ....................................................................................................................................................... 6
DOOR .............................................................................................................................................................................. 7-8
TO REMOVE THE DISPENSER ......................................................................................................................................... 8
DOOR ALIGNMENT ........................................................................................................................................................... 8
FAN AND FAN MOTOR(Evaporator) .................................................................................................................................. 8
ICE FAN SCROLL ASSEMBLY REPLACEMENT ...............................................................................................................9
DEFROST CONTROL ASSEMBLY .................................................................................................................................... 9
LAMP .................................................................................................................................................................................. 9
CONTROL BOX-REFRIGERATOR .................................................................................................................................... 9
MULTI DUCT .................................................................................................................................................................... 10
MAIN PWB, DISPLAY PWB REPLACEMENT, FUNNEL REPLACEMENT ..................................................................... 10
SUB PWB FOR DISPENSER, DUCT DOOR REPLACEMENT, ICE CORNER DOOR
REPLACEMENT, ICE MAKER ASSEMBLY ..................................................................................................................... 11
AUGER MOTOR COVER, AUGER MOTOR REPLACEMENT ........................................................................................ 12
DOOR ICE BIN ................................................................................................................................................................. 13
HOW TO REMOVE AND REINSTALL THE PULLOUT DRAWER .............................................................................. 14-17
4. ADJUSTMENT ............................................................................................................................................................ 17-19
5. CIRCUIT DIAGRAM .......................................................................................................................................................... 20
6. TROUBLESHOOTING (Error Code) ................................................................................................................................ 21
7. PCB PICTURE ............................................................................................................................................................. 22-23
8. TROUBLESHOOTING WITH ERROR DISPLAY ........................................................................................................ 24-32
9. TROUBLESHOOTING WITHOUT ERROR DISPLAY ................................................................................................. 33-40
10. REFERENCE ............................................................................................................................................................. 41-46
11. COMPONENT TESTING INFORMATION ................................................................................................................ 47-53
12. TROUBLESHOOTING (Compressor) ...................................................................................................................... 54-60
13. OPERATION PRINCIPLE AND REPAIR METHOD OF ICEMAKER ........................................................................ 61-63
14. DESCRIPTION OF FUNCTION & CIRCUIT OF MICOM ........................................................................................... 64-67
15. EXPLODED VIEW & REPLACEMENT PARTS LIST .................................................................................................... 68-
SAFETY PRECAUTIONS
Please read the following instructions before servicing your
refrigerator.
1. Unplug the power before handling any elctrical
componets.
2. Check the rated current, voltage, and capacity.
3. Take caution not to get water near any electrical
components.
4. Use exact replacement parts.
5. Remove any objects from the top prior to tilting the
product.

- 4 -
1. SPECIFICATIONS
Opaque Drawer Type
Linear
Fin Tube Type
Spiral Condenser
R-134a (145 g)
FREOL 8G (180 ml)
SHEATH HEATER
LED Module(27)
Bulb Lamp
VEGETABLE TRAY
COMPRESSOR
EVAPORATOR
CONDENSER
REFRIGERANT
LUBRICATING OIL
DEFROSTING DEVICE
REFRIGERATOR
FREEZER
LAMP
ITEMS SPECIFICATIONS
Side Rounded
35 3/4X 34 1/4X 69 3/4(WXDXH) 25cu.ft
308.65 (25cu.ft)
Fan Cooling
Micom Control
Full Automatic
Heater Defrost
Embossed Metal, VCM, Stainless
Bar
ABS Resin
Polyurethane Foam
DOOR DESIGN
DIMENSIONS (inches)
NET WEIGHT (pounds)
COOLING SYSTEM
TEMPERATURE CONTROL
DEFROSTING SYSTEM
DOOR FINISH
HANDLE TYPE
INNER CASE
INSULATION
ITEMS SPECIFICATIONS
Description LMX25984**
Depth w/ Handles
Depth w/o Handles
Depth w/o Door
Depth (Total with Door Open)
Height to Top of Case
Height to Top of Door Hinge
Width
Width (door open 90 deg. w/o handle)
Width (door open 90 deg. w/ handle)
A
B
C
D
E
F
G
H
I
34 1/4 in.
31 1/4 in.
27 7/8 in.
46 1/2 in.
68 3/8 in.
69 3/4 in.
35 3/4 in.
39 1/4 in.
44 1/4 in.
DIMENSIONS
25 cu. ft

- 5 -
2. PARTS IDENTIFICATION
ADJUSTABLE REFRIGERATOR SHELVING
The refrigerator compartment shelves are adjustable to
allow flexibility for storage needs.
MODULAR DOOR BINS
Three interchangeable bins can be arranged to suit your
storage needs.
REMOVABLE ICE STORAGE BIN
The ice storage bin can be removed to fill ice
buckets,coolers,or pitchers.
INTERIOR LAMPS
Two separate LED arrays light the freezer and refrigerator
interiors.
FIXED DOOR BIN
FIXED DOOR BIN
INTERIOR LAMP
1
2
3
4

- 6 -
3. DISASSEMBLY
Removing Refrigerator Door
CAUTION : Before you begin, unplug the refrigerator. Remove food and bins from doors.
Left Door -FIG. 2
1. Disconnect water supply tube by pushing back on the disconnect ring (4).-FIG. 1
2. Open door. Loosen top hinge cover screw (1).
Use flat tip screwdriver to pry back hooks on front underside of cover (2). Lift up cover.
3. Disconnect door switch wire harness. Remove cover.
4. Pull out the tube(3).
5. Disconnect the three wire harnesses (4). Remove the grounding screw (5).
6. Rotate hinge lever (6) counterclockwise. Lift top hinge (7) free of hinge lever latch (8).
CAUTION : When lifting hinge free of latch, be careful that door does not fall forward.
7. Place door, inside facing up, down onto a non-scratching surface.
Right Door -FIG. 3
1. Open door. Loosen top hinge cover screw (1). Lift up cover (2).
2. Disconnect door switch wire harness. Remove cover.
3. Disconnect wire harness (3).
4. Remove the grounding screw (4).
5. Rotate hinge lever (5) clockwise. Lift top hinge (6) free of hinge lever latch (7).
CAUTION : When lifting hinge free of latch, be careful that door does not fall forward.
6. Lift door up from middle hinge pin door.
7. Place door, inside facing up, down onto a non-scratching surface.
3-1 REMOVING AND REPLACING REFRIGERATOR DOORS
(4)
(5) (6)
(7)
(3)
(1)
(2)
(4)
(3)
(6)
(7) (8)
(5)
Figure 1
Figure 2 Figure 3
1)Insert the tube until you can see only one of the lines
printed on the tube.
2)After inserting, pull the tube to ascertain that it is secure.
3)Assemble clip.

- 7 -
3-2 DOOR
Door Gasket Removal
1. Remove door frame cover
Starting at top of cover and working down, snap cover
out and away from door.
Door Gasket Replacement
1. Insert gasket bracket clips
1) Insert gasket bracket edge beneath door frame edge.
2) Turn upper gasket bracket spring so that the spring
ends are in the door channel.
3) Push in clip until you hear it snap securely into place.
2. Insert gasket into channel
1) Snap gasket assembly into the door bracket.
<Inserting the Gasket Assembly into the Bracket Door>
4) Push in remaining clip until you hear it snap securely
into place.
Note : Make sure that no part of gasket bracket edge
protrudes from beneath door frame edge.
2. Remove gasket bracket clips
There are two clips on each door. Start bracket removal
near one of the middle clips.
1)Pull gasket back to expose gasket bracket clip and
door frame.
2)Insert a flat tip screwdriver into seam between gasket
bracket and door frame and pry back until clips snap
out.
3)Continue prying back along seam until all clips snap
out.
3. Remove gasket
Pull gasket free from gasket channel on the three
remaining sides of door.
Figure 1
Frame Cover
Handle
Figure 4
Figure 5
Door
Frame
Correct
Correct
Incorrect
Incorrect
Figure 2
Door
Frame
Gasket
Bracket Clip
Gasket
Bracket
Flat Tip
Screwdriver
Figure 3
Spring
Gasket
Bracket Clip

- 8 -
3. Replace door frame cover
Starting at top of cover and working down, snap cover
back into door.
2) Press gasket into channels on the three remaining sides
of door.
Figure 6
Figure 8
Figure 9
Figure 7
3-3 DOOR ALIGNMENT
If the space between your doors is uneven, follow the
instructions below to align the doors:
1. Remove the Base Grillie.
2. Turn the leveling legs (CCW) to raise or (CW) to lower
the height of the front of the refrigerator by using flat
blade screw driver or 11/32" wrench.
3. Use the wrench (Included with the User Manual) to
adjust the bolt in the door hinge to adjust the height.
(CCW to raise or CW to lower the height.)
3-4 FAN AND FAN MOTOR(EVAPORATOR)
1. Remove the freezer shelf. (If your refrigerator has an
icemaker, remove the icemaker first)
2. Remove the plastic guide for slides on left side by
unscrewing phillips head screws.
3. Remove the grille by removing one screw and pulling the
grille forward.
4. Remove the Fan Motor assembly by loosening 2 screws
and disassembling the shroud.
5. Pull out the fan and separate the Fan Motor and Bracket.
BRACKET
MOTOR
GRILLE
FAN
FAN MOTOR
CAUTION
DO NOT ATTEMPT TO REMOVE THE MULLION :
REFRIGERANT LINES!

- 9 -
*Ice Fan Scroll Assembly Replacement
1) Remove the plastic guide for slides on left side by
unscrewing phillips head screws.
2) Pull the grille forward as shown in the second picture.
3) Disconnect wire harness of the grille.
4) Remove the scroll assembly by loosening all screws.
(3) (4)
Figure 12
Figure 13
Figure 15
Figure 14
3-5 DEFROST CONTROL ASSEMBLY
Defrost Control assembly consists of Defrost Sensor and
FUSE-M.
The Defrost Sensor works to defrost automatically. It is
attached to the metal side of the Evaporator and senses its
temperature. At 46°F (8°C), it turns the Defrost Heater off.
Fuse-M is a safety device for preventing over-heating of the
Heater when defrosting.
1. Pull out the grille assembly. (Figure 10)
2. Separate the connector with the Defrost Control
assembly and replace the Defrost Control assembly after
cutting the Tie Wrap. (Figure 11)
Figure 10 Figure 11
GRILLE ASSEMBLY DEFROST-CONTROL
ASSEMBLY
Cover, Lamp LED, Assembly Case Lamp
3-6 LAMP
Unplug Refrigerator, or disconnect power at the circuit
breaker.
If necessary, remove top shelf or shelves.
1) Release 2 screws.
2) Hold both ends with your both hands and pull it
downward to remove it.
3) Use a flat tool as shown below to remove the cover
lamp.
3-6-1 Refrigerator Compartment Lamp
1. Unplug refrigerator power cord form outlet.
2. Remove screw with driver.
3. Grasp the cover Lamp, pull the cover downward.
3-6-2 Freezer Compartment Lamp
(1) (2)
CAUTION
DO NOT ATTEMPT TO REMOVE THE MULLION :
REFRIGERANT LINES!
4) As shown below, use a flat tool to remove the cover
lamp.

- 10 -
3-7 MULTI DUCT
1. Remove the upper and
lower Caps by using a
flat screwdriver, and
remove 2 screws.
(Figure 16)
2. Disconnect the lead wire
on the bottom position.
3-8 MAIN PWB
1) Loosen the 4 screws on the PWB cover.
Figure 16
3-9 DISPENSER
1) Pull out the darin 2) Hold the inner side of
cover dispenser with both
hands at the handle side
to pull it out forward.
2) Remove the PWB cover
3) Disconnect wire harness and replace the main PWB in
the reverse order of removal.
CAUTION : When replacing the dispensor cover in the
reverse order of removal, be careful that the lead wire
does not come out and the water tube is not pinched by
the dispensor,
3) If nozzle is interfered with button ,
push and pull out the bottom of
button.
4) Rmove the
connected part
of Lead wire.
3-10 DISPLAY PCB
As shown below, remove 1 case PCB fixing screw.
Remove the display PCB fixing screw.
3-11 ICE BUTTON ASSEMBLY
1) Remove the screw fixing the button lever.
2) Push the spring from the hanging hook to remove it.
3) Apply some pressure to the rib in direction and lift the
button in direction.
3-12 FUNNEL REPLACEMENT
Pull down and forward.
Case, PCB Display PCB
Button Lever

- 11 -
3-15 ICE CORNER DOOR REPLACEMENT
1) Loosen the front screw as shown in the picture.
2) Lift up the hinge with one hand.
3) Pull out the Ice Corner Door with the other hand.
3-16 ICEMAKER ASSEMBLY
1) Loosen two screws as shown in the first picture.
2) Disconnect the wire harness & ground screw replace
theIcemaker assembly in the reverse order of removal.
3-14 DUCT DOOR REPLACEMENT
1) Pull up and out on the dispenser cover to remove.
2) Disconnect the wire harness.
3) Remove the funnel
4) Replace in reverse order.
3) It separates a ground connection screw.
3-13 WATER BUTTON ASSMEBLY
1) Romove screws.
2) Grasp the Button assembly and lift up.
Button Lever

- 12 -
3-17 AUGER MOTOR COVER
1) After removing the icemaker remove the (5) stainless
screws holding the auger motor cover, shown in the
picutres below.
2) Grip the bottom of motor cover assembly and pull out it.
3) Disconnect wire harness of motor cover assembly.
There is a auger motor on the back, as shown in the
picture.
Auger Motor
Icemaker Power &
Full detection Signal

- 13 -
3-20 HOW TO REMOVE A DOOR ICE BIN
1) Grip the handles, as shown in the picture.
3-21 HOW TO INSERT A DOOR ICE BIN
1) Insert the Ice Bin, slightly tilting it to avoid touching the
Icemaker. (especially, ice maker lever)
Insert the ice bucket carefully avoid contacting the
automatic shut off arm.
2) Lift the lower part slightly.
3) Take the Ice Bin out slowly.

- 14 -
3-22 HOW TO REMOVE AND REINSTALL THE PULLOUT DRAWER
3-22-1 Follow Steps to Remove
Step 1) Open the freezer door. Step 2) Remove the lower basket.
Step 3) Remove the two screws from the guide rails (one
from each side).
Step 5) First: Remove the gear from the left side first by releasing the tab behind the gear, place a screwdriver between the
gear and the tab and pull up on the gear.
Second: Remove the center rail.
Third: Remove the gear from the right side by following the same steps for the left side.
NOTE : THIS TAB MUST BE PUSHED IN TO RELEASE THE GEAR.
Step 4) Lift the freezer door up to unhook it from the rail
support and remove.
Pull both rails to full extension.

- 15 -
3-22-2 Follow Steps to Reinstall
Step 1) Reinstall the right side gear into the clip.
Step 2) Insert the rail into the right side gear. Gears do not
need to be perpendicular to each other.
Step 4) The rail system will align itself by pushing the rails
all the way into the freezer section.
Pull the rails back out to full extension.
Step 5) Reinstall the freezer door by inserting the rail tabs
into the guide rail.
Step 6) Reinstall the two screws into the guide rails
(one from each side).
Step 7) Reinstall the lower basket, and close the freezer
door.
Step 3) Insert the rail into the left side gear, and insert the
gear into the clip.

- 16 -
3-23 WATER VALVE DISASSEMBLY METHOD
1) Turn off the water. Then separate the water line from the
valve.
3-24 FAN AND FAN MOTOR DISASSEMBLY
METHOD
1) Using a short screwdriver, loosen one SCREW in DRAIN
PIPE ASSEMBLY and one connected to the MOTOR
COVER.
2) Separate the Mechanical Cover and Valve Screw.
3) Separate the housing and pull out the valve.
4) Lay a dry towel on the floor and get ready to spill water
from the water filter. Pull out the Cilp. Then press te
collet to separate the tube from the connector and pour
out the water until emptied.
Mechanical Cover
Housing
MOTOR COVER
2) Pull and separate the FAN ASSEMBLY and MOTOR
turning counterclockwise based on the MOTOR SHAFT.
The assembly is in the reverse order of the disassembly
and take special care for the following details.
1. Be careful not to bend the tube during assembly.
2. Press the WATER DISPENSER button until water pours
out and check for leakage in the CONNECTOR TUBE (It
differs by the water pressure but usually takes about 2
minutes until water pours out.)
FAN ASSEMBLY MOTOR
Collet
Tube
Insert Line
Clip

- 17 -
3-25 TOP DRAWER
To remove the freezer drawer, pull the drawer open to full extension. Remove the drawer and Ice Bin lifting the basket from
the rail system.
3-26 BOTTOM DRAWER
To remove the freezer drawer, pull the drawer open to full extension. Remove the lower DuraBase ®basket by lifting the
basket from the rail system.

- 18 -
4. ADJUSTMENT
4-2 INTRODUCTION OF E-LINEAR COMRESSOR
E-Linear compressor is run by mechanical part design
through automatically varying the cooling power. The
main parts consist of compressor and Sub PCB which
controls the compressor. PCB authorizes constant
voltage and constant frequency to the compressor and
protects it.
Drive half stroke after turning on initial power for 1
second. Then, Reach Target Voltage by increasing
0.35 Vrms per every 0.3 second. Once reaching the
target input, input naturally changes according to
refrigerator load without any special control.
Interval 1) Half stroke interval - after initial running, stay at
the initial value for 1 second
Interval 2) Running interval - Increase at every 0.3 till it
reaches the target input; it takes about 1 minute
Interval 3) CVCF interval - Run by target voltage and main
operating frequency and the input naturally
changes according to refrigerator load
❸
❶❷
4-1-1 Role
4-1 COMPRESSOR
The compressor intakes low temperature and low pressure
gas from the evaporator of the refrigerator and compresses
this gas to high-temperature and high-pressure gas. It then
delivers the gas to the condenser.
4-1-2 Note for Usage
(1) Be careful not to allow over-voltage and over-current.
(2) Do not drop or handle carelessly.
(3) Keep away from any liquid.
If liquid such as oil or water enters the Cover PTC
Compressor may fail due to breakdown of their
insulating capabilities.
(4) Always use the Parts designed for the compressor and
make sure it is properly attached to the compressor.
Parts may appear physically identical but could have
different electrical ratings. Replace parts by part number
and model number. Use only approved substitute parts.
4-1-3 Remove the cover PTC
(1) Remove the Cover Back M/C
(2) Loosen two screws on comp base
(3) Use a L-shaped flap tooll to pry off the cover
(4) Assembly in reverse order of disassembly
4-2-1 Control of Compressor Block Diagram
4-2-2 Compressor operating pattern
Compressor Controller Inverter
PWM
Signal
Frequ
-ency
Linear
Comp
DC link
Voltage
Main
Micom
Calculate counter
electromotive force
Counter elec-
tromotive force
Vcap Voltage
Control Block Diagram of Compressor
Comp. input

- 19 -
Multi-tester
4-2-4 Compressor problems diagnosis
When there is a problem or failure with the `operation,
you are kindly recommended to check it as follows ;
Measure the resistance between poles of the hermetic
terminal (as shown picture) with a multi-tester.
(measurement several minutes after power off)
Normal resistance range (measured at ambient
temperature 23 )
Case 1-1
If the measured values lie in the normal resistance range as
in the table below,
Compressor is normal.
Case 1-2
If the measured values are above several M or a infinity,
Wire is disconnected in the shell.
Case 1-3
If the measured values are excessively of small number,
There is short somewhere in the shell.
1) Check to normality by measurement of resistance
According to ambient temperature or operation situation,
the values could show a little deviation.
4-2-3 Compressor protection logic
Since linear Comp conducts linear reciprocating motion,
we have protection logic for compressor, motor and PCB
as the below.
-Stroke Trip
During the operation, if stroke is above the target value,
decrease the target volt by 3V.
-Current Trip
Current trip is set in order to protect compressor
mechanical part and drive from the overcurrent that might
arise during the operation.
Check the current for every 416.7us and if the Trip
exceeds 1.86Arms more than three times at Comp ON,
forcibly stop and restart six minutes later.
-Lock Piston Trip
If stroke is under 5mm even if the current is more than
14Arms, Take it as ‘piston lock’ and restart after 2’30” of
Comp OFF. Check the current and stroke for every
416.7us and if the condition fits more than three times at
Comp ON, the Trip occurs.
-IPM fault Trip
It occurs if FO signal received from IPM is LOW. For
every 416.7us, check whether FO signal is LOW. The trip
occurs if it is found three times during the five
periods(83ms).
P : Power Line
C : Common Line
Resistance
6~8
FC75LANE

- 20 -
Measure the resistance between pin of the connector (as
shown picture) with a multi-tester.
Standard for normality
-In order to decide whether compressor operating is normal
or not, check the output transfer during the refrigerator
operation.
-After input the initial power and compressor operates, wait
for 10 minutes to estimate.
-Compressor operation may be diagnosed as normal if the
voltage falls between 145V and 180V.
Warning
1. Please be cautious of electric shock and short (it is
estimated after turning on initial power).
2. If the voltage is estimated less than 80V, it is diagnosed
as bad.
2) Check to normality by measurement of Voltage
If compressor protection logic is running, LED Lamp’s
blinking frequency of sub PCB, which takes in charge of
control, can help estimate the protection logic’s symptoms
and the cause of its problems.
Trip name
Stroke Trip
Current Trip
Lock Piston Trip
IPM fault trip
Led Times
2
6
5
7
Comp Off Time
1min
6min
2min 30sec
20sec
3) Check problems by LED On & Off Count _ (Sub PCB)
<Fig. 1> <Fig. 1> -Current Trip PCB defects or Cycle clogging maybe the
causes. After estimating winding resistance, estimate
compressor operation voltage to check if there is any
problem and take actions to repair cycle at replacement of
compressor.
-Stroke Trip can occur when the surrounding
temperature is high, C-Fan, F-Fan and so on are
constrained, or when cycle problems, such as moisture
blocking or compressor defect, are related.
-Lock Piston Trip Since compressor itself can be a
potential cause of a defect, estimate the compressor
resistance value according to #1’s compressor winding
value estimation method and estimate the #2’s
compressor operation voltage to decide whether it is
defective or not
(Before replacement of compressor, replace PCB and
conduct the replacement of compressor during
compressor replacement)
-IPM fault Trip Replace sub PCB since there is high
chance that it is caused by sub PCB’s part defect.