LG LMX21981 Series, Training Manual

Page 1: ...LG TRAINING MANUAL LG TRAINING MANUAL Four Door Refrigerator LMX21981 Fall 2008 ...

Page 2: ...ademy com Technical training Contact Number Hours of Operation Customer Service 800 243 0000 24 7 365 days a year Technical Support 800 847 7597 7am 7pm Mon Fri Sat 8 2 CST Parts Sales 888 393 6484 7am 7pm Mon Sat CST Training Center 256 774 4051 8am 5pm Mon Fri CST Published August 2008 by LG Electronics USA Trainng Center Copyright 2008 LG Electronics of Alabama Inc Phone Contacts Web Contacts ...

Page 3: ... or Cubed Ice 17 Dispensing Water 17 Dispenser Light 17 Setting the Dispenser Lock 18 Setting the Door Alarm 18 Resetting the Filter Indicator 19 Activating ICE PLUS 19 Diagnostic Failure Detection 19 Replacing the Water Filter 20 Disassembly 21 Removing and Replacing Refrigerator Doors 21 Icemaker Door 23 Remove and Replace the Pullout Freezer Door 23 Reinstall the Pullout Freezer Door 25 Dispens...

Page 4: ...How It Works 46 Refrigerator LED Module 48 Defrost Control Assembly 50 Thermistor Tips 51 Thermistors Sensors 52 Room Thermistor 52 Temperature Compensation 52 Multi Duct 53 Stepper Motor 54 Compressor PTC Positive Temperature Coefficient 54 Compressor OLP Overload Protector 55 Replacing the OLP 56 Circuit Diagram Block 57 Test Mode 58 Error Codes 59 Error Code Er rt 60 PCB Function 61 Power Circu...

Page 5: ... in the appliance Before removing a replacement part from its package touch the anti static bag to a ground connection point or unpainted metal in the appliance Handle the electronic control assembly by its edges only When repackaging a failed electronic control assembly in an anti static bag observe these same precautions REGULATORY INFORMATION This equipment has been tested and found to comply w...

Page 6: ...LMX21981xx REFRIGERATOR LMX21981xx Page 4 TRAINING MANUAL SPECIFICATIONS ...

Page 7: ...LMX21981xx REFRIGERATOR LMX21981xx Page 5 TRAINING MANUAL ...

Page 8: ...LMX21981xx REFRIGERATOR LMX21981xx Page 6 TRAINING MANUAL PARTS IDENTIFICATION ...

Page 9: ...ck plate is installed remove it by removing the two screws that hold it on When the refrigerator is in place adjust the leveling legs by turning them counterclockwise to raise or clockwise to lower the refrigerator Use an 11 32 8 mm wrench to turn the hex ends of the leveling bolts or stick a flat screwdriver in the slots to turn them If you have a helper to push against the top of the refrigerato...

Page 10: ...akly supported structure When moving the refrigerator for cleaning or service be sure to protect the floor Pull the refrigerator straight out Do not walk or wiggle it floor damage or side panel damage may occur HANDLE REMOVAL It may be necessary to remove the handles to get the refrigerator through a door Loosen the set screws with a 3 32 2 5 mm Allen wrench Remove the handle If the mounting bolts...

Page 11: ... the base grille kick plate or bottom of the refrigerator You could be injured or shocked If the entrance door is too small to accommodate the refrigerator you can remove the doors and pull the refrigerator into the room sideways RIGHT REFRIGERATOR DOOR Open the door to 90 Remove the top hinge cover 1 screw Lift the cover 2 Disconnect the wire 3 harness Rotate the hinge lever 4 clockwise and remov...

Page 12: ...off 2 the hinge cover Hooks not shown Remove the cover and pull the water tube 3 through Disconnect all the wiring 4 harnesses Remove the ground 5 screws Turn the hinge lever 6 counter clockwise and remove it Lift the top hinge 7 free of the latch lever 8 Be careful the door does not fall forward With the door open to 90 lift it off the middle hinge pin CAUTION When lifting the hinge free of the l...

Page 13: ...erly assembled to avoid leaking Insert the tube into the connector until only one of the printed lines is visible Pull on the tube slightly to ensure proper insertion and retention Insert the retainer clip under the release ring If you can see both rings the tube is not inserted properly The tube end must be cut squarely ...

Page 14: ...g or a braided reinforced nylon supply line Install the water line in an area where the temperature will not drop below freezing It may take up to 24 hours for the icemaker to begin producing ice The icemaker water valve includes a flow washer that is used as a water pressure regulator TOOLS REQUIRED Standard screwdriver nut driver 7 16 open end wrench open end wrench drill bit drill electric dril...

Page 15: ... the water line fittings After the valve has been installed on the water line it must be flushed before connecting it to the refrigerator Remove the plastic cap from the water valve on the back of the refrigerator Attach the water supply line to the valve Open the valve and flush out the supply line before attaching it to the refrigerator Attach the supply line to the water valve on the back of th...

Page 16: ... Press the REFRIGERATOR button to adjust the temperature in the refrigerator compartment NOTE When pressed simultaneously with the FREEZER button for more than five seconds the temperature display will change from Fahrenheit to Celsius or vice versa 5 ICE PLUS BUTTON Press this button to turn on the ICE PLUS feature which increases ice making capabilities up to about 20 percent 6 LIGHT FILTER BUTT...

Page 17: ...erature of the refrigerator compartment in degrees Celsius or Fahrenheit 4 ICE PLUS When the ICE PLUS button is pressed the display will indicate the selected function has been activated 5 DISPENSER LIGHT INDICATOR When the LIGHT button is pressed the display will indicate the selected function When the dispenser light is on this indicator will appear on the display panel 6 DOOR ALARM INDICATOR Th...

Page 18: ... Leave them at these setting for 24 hours one day to stabilize Then adjust the compartment temperature as illustrated above To change the temperature display from Fahrenheit to Celsius or vice versa simultaneously press and hold the FREEZER and REFRIGERATOR buttons for more than 5 seconds Display Power Saving Mode This function places the display into the Power Saving Mode Simultaneously press the...

Page 19: ...ntainer in place for a couple of seconds after dispensing ice or water to catch the last few cubes or drops The dispenser is designed to not operate while either refrigerator door is open DISPENSING WATER Press the push water switch or active water button with a glass or other container and chilled water will be dispensed When the water switch or active water switch is pressed the light will be il...

Page 20: ...ER LOCK Press and hold the ALARM LOCK button for three seconds to lock the dispenser and all of the other control panel functions Press and hold again for three seconds to unlock SETTING THE DOOR ALARM The ALARM LOCK button also controls the door alarm that sounds three times in 30 second intervals when a compartment door is left open for more than 60 seconds The alarm stops sounding when the door...

Page 21: ...distributor You can also call 1 877 714 7486 The replacement water filter cartridge s part number is 5231JA2006A ACTIVATING ICE PLUS Press the ICE PLUS button once to activate the ICE PLUS function The ICE PLUS icon on the display panel will illuminate when activated The ICE PLUS function runs the freezer compartment at the coldest setting for a 24 hour period to increase icemaking by up to about ...

Page 22: ...kaging and remove the protective cover from the o rings Hold the cartridge handle in its vertical position and firmly push the new filter cartridge into place until it stops Use the handle to twist the cartridge clockwise about one turn until the handle is in a horizontal position You will feel the filter click into place NOTE If the filter will not turn from side to side it isn t fully inserted A...

Page 23: ...ng screw 6 6 Rotate hinge lever 7 counterclockwise and remove Lift the top hinge 8 free of the hinge lever latch 9 CAUTION When lifting the hinge free of the latch be careful that the door does not fall forward 7 Place the door inside facing up onto a non scratching surface Right Door FIGURE 3 Next Page 1 Open the door Loosen the top hinge cover screw 1 Lift up the cover 3 2 Disconnect the door sw...

Page 24: ...LMX21981xx REFRIGERATOR LMX21981xx Page 22 TRAINING MANUAL ...

Page 25: ...ront screw nearest the hinge of the bracket Lift the hinge with one hand It might be necessary to loosen the rear screw slightly Lift the icemaker door out of the lower hinge with the other hand REMOVE and REPLACE the PULLOUT FREEZER DRAWER Open the freezer door Remove the lower basket ...

Page 26: ...unhook it from the rail support and remove Pull both rails to full extension 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 Remove the center rail 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 ...

Page 27: ...OW THESE STEPS TO REINSTALL Reinstall the right side gear into the clip Insert the rail into the right side gear The gears do not need to be perpendicular to each other Insert the rail into the left side gear and insert the gear into the clip continued on next page ...

Page 28: ... align itself by pushing the rails all the way into the freezer section Pull the rails back out to full extension Reinstall the freezer door by inserting the rail tabs into the guide rail Reinstall the two screws into the guide rails one from each side Reinstall the lower basket and close the freezer door ...

Page 29: ...ll the tray out past the stops without breaking it NOTE Pay close attention to the clip that is located under the tray Look at how it is installed in case it comes out while removing the dispenser assembly Remove the tray Lift out the grate Then pull the tray out past the stops without breaking it Release the lower clips ...

Page 30: ...LMX21981xx REFRIGERATOR LMX21981xx Page 28 TRAINING MANUAL DISPENSER ASSEMBLY continued Release the side clips Loosen all four edges Pull the dispenser assembly forward and remove all the connectors ...

Page 31: ... TRAINING MANUAL DISPENSER ASSEMBLY continued Back view of dispenser Display PCB DISPLAY WHITE BLACK 12VDC to Display Board BRIGHT ORANGE Ground BROWN RX RX to Ground Receives Variable VDC Pulse RED TX TX to Ground Transmits Variable VDC Pulse ...

Page 32: ...UE WHITE 12VDC from PC to WHITE on LED CON 4 BLUE WH to PK CON 6 or BOR Door CLOSED 0 VDC Door OPEN 12VDC REFRIGERATOR DOOR SWITCH GRAY to GRAY N C Switch Door OPEN Switch CLOSED CON 4 Door CLOSED 4 5 VDC Door OPEN 0 VDC This is a monitoring circuit FREEZER DOOR SWITCH Brown to Brown N C Switch Door Closed Switch is OPEN CON 6 0 VDC Door OPEN 4 5 VDC Door CLOSED This is a monitoring circuit ...

Page 33: ...s The feeler arm senses the amount of ice while the ejector rotates If the bin is full the heater is turned off and the ejector stops If the bin is not full the ejector rotates two turns to eject the ice and begin a new cycle If the ejector does not rotate at least one full turn within five minutes a separate heater control mode activates to prevent damage to the icemaker FILL PARK MODE After the ...

Page 34: ...ccessed while the icemaker is filling or ejecting Press and hold the cube size button for more than three seconds to put the icemaker into test mode The test cycle can be used to diagnose icemaker issues and to clean it The test mode can be started only in ice making mode it cannot be accessed while the icemaker is filling or ejecting CAUTION If the icemaker is cycled through test mode before the ...

Page 35: ... If the icemaker does not operate normally during test mode turn it off Check it and repair as necessary or replace When the test cycle is complete the icemaker reverts to MICOM control and assumes the factory default fill setting DIAGNOSTIC CHART ERROR CODES ...

Page 36: ...LMX21981xx REFRIGERATOR LMX21981xx Page 34 TRAINING MANUAL MAIN CONTROL BOARD CONNECTOR REFERENCE ...

Page 37: ...supply to icemaker and refrigerator door BLACK 120 VAC to compressor when activated GREY 120 VAC to water dispenser pilot valve rear when activated WHITE 120 VAC to defrost circuit when activated BROWN 120 VAC to heaters pulsing OFF ON BLUE Neutral constant RED 120 VAC to icemaker pilot valve rear when activated ICEMAKER REMOVAL Remove five AC motor assembly screws Remove the entire icemaker assem...

Page 38: ...ICEMAKER REMOVAL continued Separate the two electrical connectors Remove the upper screws Remove the ground screw Replace it in the icemaker assembly in the event you need to reuse it or require it in the replacement unit Separate the 4 pin electrical connector ...

Page 39: ...LMX21981xx REFRIGERATOR LMX21981xx Page 37 TRAINING MANUAL ICEMAKER SERVICE BULLETIN ...

Page 40: ...LMX21981xx REFRIGERATOR LMX21981xx Page 38 TRAINING MANUAL ...

Page 41: ...LMX21981xx REFRIGERATOR LMX21981xx Page 39 TRAINING MANUAL ...

Page 42: ...e collet release ring Separate the mechanical cover and remove the screw that holds the valve assembly to the refrigerator Separate the housing Pull out the valve Lay a dry towel on the floor and be ready to spill water from the filter line Remove the release guard clip and press the collet to separate the tube from the connector Allow the water to drain from the line until it is empty ...

Page 43: ...LMX21981xx REFRIGERATOR LMX21981xx Page 41 TRAINING MANUAL ICE AND WATER VALVES Remove the tilt drawer door bin Remove the valve access panel Reservoir tubing and valves Ice and water valves ...

Page 44: ...d then once every thirty minutes The input voltage and signal voltages are measurable To clear the ER error code unplug repair and replace the fan motor Or if you wait thirty minutes the situation will clear itself The fan speed is controlled by the sensor temperature If the signal is interrupted the motor will run for five minutes After that time the fan will stop and an error code will be displa...

Page 45: ...L Positive While Operating RD to BL Approx 11 1 VDC BL to BR 2 5 VDC Door OPEN or OFF 0 VDC CONDENSER FAN SKY BLUE SUPPLY Positive BRIGHT ORANGE GROUND YELLOW SIGNAL Positive While operating SB to BO Appox 11 1 VDC Y to BO 2 5 VDC Door OPEN or OFF 0 VDC EVAPORATOR and ICE ROOM FAN ACCESS Remove the top drawer rails ...

Page 46: ...rd you Separate the connectors and you can remove the entire panel assembly from the freezer NOTE The ice room fan supplies air to the ice room through ducting in the cabinet Where the door meets the cabinet there are gaskets to seal the ducts between them allowing the air to go into the ice room The air supply enters through the top and the return is on the bottom ...

Page 47: ...mponents CAUTION DO NOT ATTEMPT TO REMOVE THE MULLION IT CONTAINS REFRIGERANT LINES The rear panel can be easily removed after removing the left and right upper door supports The panel can then be slid through the upper door opening above the mullion LED LAMPS REFRIGERATOR If necessary unload remove the top shelves Remove the two screws Grasp both ends of the lamp assembly and pull it down and out...

Page 48: ...or switch Each door switch is 2 switches in one These door switches have 2 single pole single throw normally closed NC switches The door open perception switch shown in CON 4 pins 11 and 12 is a 5 VDC refrigerator door monitoring switch Notice the wire colors connecting these terminals to the refrigerator door switches are gray GY These gray wires attach to terminals H I shown on the R Door switch...

Page 49: ... 15 PK 12 VDC should be present at ALL times on pins 1 and 2 RD to BK on both LED modules This 12 VDC will be used to operate the LEDs in each module when the signal voltage arrives on Pin 3 WH Pin 13 SB on CON 6 of the main power board is a 12 VDC output going to each door switch in the refrigerator and freezer sections The 2nd switch in each door switch supplies this 12 VDC when the door is open...

Page 50: ...LMX21981xx REFRIGERATOR LMX21981xx Page 48 TRAINING MANUAL REFRIGERATOR LED MODULE White to Black Door closed 0 VDC White to Black Door open 12 VDC ...

Page 51: ...ed Red to Black 12 VDC Constant The freezer LED assembly is similar to the refrigerator but smaller The repair procedure is the same SKY BLUE 12 VDC supply to all LED door switches WHITE Wires GRAY 12 VDC supply to all LED modules RED Wires PINK Negative to all LED door switches BLACK wires ...

Page 52: ...se Fuse M is for safety to prevent overheating during the defrost cycle The thermal fuse is a single use item when it blows it must be replaced as an assembly Remove the grille assembly in the freezer Unplug the defrost control assembly Cut the tie wrap that holds it in place Remove and replace the assembly Secure it with a new tie wrap Plug in the new assembly and replace the grille In the two ph...

Page 53: ... if the internal temperatures are above 46 F If a sensor fails The refrigerator sensor cycles the damper and evaporator fan every fifteen minutes while the error code Er rS is displayed The freezer sensor cycles the compressor evaporator fan motor and condenser fan motor every fifteen minutes while the error code Er FS is displayed The ice room sensor cycles the ice room fan every fifteen minutes ...

Page 54: ...ature DECREASES the resistance INCREASES As the resistance INCREASES the voltage DECREASES Refer to page 74 for the Temperature Resistance Chart ROOM THERMISTOR BROWN to BROWN 0 5 4 5 VDC Resistance Disconnect the wire connector Set the meter to Ω Refer to page 74 for the Temperature Resistance Chart TEMPERATURE COMPENSATION Opening jumpers JCR1and 2 will increase the refrigerator temperature by 1...

Page 55: ...emove the two screws Separate the electrical connectors when the duct is removed Replace the foam gasket if it is damaged Be sure the newly adhered gasket does not interfere with damper operation Store the duct where it will not be damaged or crushed during repairs Replacement is the reverse of this procedure ...

Page 56: ... Temperature Coefficient The PTC Positive Temperature Coefficient is a non contact ceramic semiconductor that uses BaTiO3 The resistance increases as the temperature increases This part is attached to the compressor case and used to start the compressor and to prevent starting when conditions require The compressor is a single phase induction motor The PTC allows current to energize both the start...

Page 57: ... repeat itself 3 to 5 times while the compressor tries to restart until the PTC cools sufficiently It is critical to use the correct parts when replacing the OLP and PTC or the compressor will be damaged Parts may appear physically identical but could have different electrical ratings Order replacement parts by model number and serial number OVERLOAD PROTECTOR OLP The OLP Over Load Protector is at...

Page 58: ...or to expose the compressor and mechanical area Remove the two screws on the retaining clamp of the compressor Loosen two screws on the compressor base Use a flat screwdriver to pry off the cover Remove and replace the OLP and the PLC These should be replaced as a set Replace the cover and tighten all screws loosened ...

Page 59: ...LMX21981xx REFRIGERATOR LMX21981xx Page 57 TRAINING MANUAL CIRCUIT DIAGRAM ...

Page 60: ...sing test button at main PCB controller 3 While in the test mode the function control button is not recognized but the recognition tone sounds 4 After exiting the test mode be sure to reset by unplugging and then plugging in the appliance 5 If an error such as a sensor failure is detected while in the test mode the test mode is cleared and the error code is displayed 6 While an error code is displ...

Page 61: ...LMX21981xx REFRIGERATOR LMX21981xx Page 59 TRAINING MANUAL ERROR CODES ...

Page 62: ...MANUAL ERROR CODE Er rt The error code Er rt will show on the display at the beginning of the test mode if there is a defective ambient sensor reading Otherwise it will not be seen by the customer and does not affect normal operation of the refrigerator ...

Page 63: ... the BLDC FAN Motor drive 15 5 VDC the relay drive 12 VDC and the MICOM and IC 5 VDC The voltage for each part is as follows VA1 is a part for preventing over voltage and noise When 230 V or higher power is applied the inside elements are short circuited and broken resulting in blowout of the fuse in order to protect the elements of the secondary part of the TRANSFORMER ...

Page 64: ...LMX21981xx REFRIGERATOR LMX21981xx Page 62 TRAINING MANUAL POWER CIRCUIT continued LOAD FAN and DOOR OPEN DETECTION CIRCUIT ...

Page 65: ...LMX21981xx REFRIGERATOR LMX21981xx Page 63 TRAINING MANUAL OPEN DOOR DETECTION CIRCUIT CHECK ...

Page 66: ...LMX21981xx REFRIGERATOR LMX21981xx Page 64 TRAINING MANUAL REFRIGERATION COMPARTMENT STEPPING MOTOR DAMPER CIRCUIT LED IN REFRIGERATOR FREEZER Optional ...

Page 67: ...LMX21981xx REFRIGERATOR LMX21981xx Page 65 TRAINING MANUAL LED IN REFRIGERATOR FREEZER Optional continued MAIN PWB ASSEMBLY ...

Page 68: ...LMX21981xx REFRIGERATOR LMX21981xx Page 66 TRAINING MANUAL DISPENSER DRIVE PWB ASSEMBLY ...

Page 69: ...LMX21981xx REFRIGERATOR LMX21981xx Page 67 TRAINING MANUAL EXPLODED VIEWS ...

Page 70: ...LMX21981xx REFRIGERATOR LMX21981xx Page 68 TRAINING MANUAL EXPLODED VIEWS continued ...

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Page 74: ...LMX21981xx REFRIGERATOR LMX21981xx Page 72 TRAINING MANUAL EXPLODED VIEWS continued ...

Page 75: ...LMX21981xx REFRIGERATOR LMX21981xx Page 73 TRAINING MANUAL EXPLODED VIEWS continued ...

Page 76: ...LMX21981xx REFRIGERATOR LMX21981xx Page 74 TRAINING MANUAL TEMPERATURE RESISTANCE CHART ...

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Page 78: ...Four Door Refrigerator Fall 2008 ...