LG WM4370H A Series Service Manual Download Page 1

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WASHING MACHINE

SERVICE MANUAL

CAUTION

READ THIS MANUAL CAREFULLY TO DIAGNOSE
PROBLEMS CORRECTLY BEFORE SERVICING THE UNIT.

MODEL: WM4370H*A

Website : http://biz.lgservice.com

Any reproduction, duplication, distribution (including by way of email, facsimile or other electronic means),

publication, modification, copying or transmission of this Service Manual is STRICTLY PROHIBITED unless you

have obtained the prior written consent of the LG Electronics entity from which you received this Service

Manual. The material covered by this prohibition includes, without limitation, any text, graphics or logos in this

Service Manual.

Summary of Contents for WM4370H A Series

Page 1: ...other electronic means publication modification copying or transmission of this Service Manual is STRICTLY PROHIBITED unless you have obtained the prior written consent of the LG Electronics entity from which you received this Service Manual The material covered by this prohibition includes without limitation any text graphics or logos in this Service Manual Copyright 2016 2017 LG Electronics Inc ...

Page 2: ...3 Troubleshooting With Error 21 27 7 5 Before using the Tag On function 33 7 4 Troubleshooting Else 28 32 8 Component Testing Information 34 8 1 Filter Assembly Line Filter 34 8 2 Door Look Switch Assembly 35 36 8 3 Stator Assembly 37 39 8 4 Pump Motor Assembly 40 8 5 Inlet Valve Assembly 41 8 6 Heater Assembly 42 8 7 Thermistor Assembly 43 44 9 Disassembly Instructions 45 53 10 Exploded View 54 5...

Page 3: ...7 W X 293 4 D X 3811 16 H 51 D door open up to 19 hours CHROME 10 steps by sensor Incorporated Incorporated Incorporated Incorporated Incorporated 240 W 80 W 1200 W 46 rpm 0 1 300 rpm Blue White VCM Black STS z H 0 6 V 0 2 1 C A 202 8lb 92kg y r t s u d n i l l a o t e r e h d a s n o s r e p o t y r u j n i f o k s i r e h t e c u d e r o T recommen de d safetyproc edures including the use o g n ...

Page 4: ...etects the load and optimizes the washing time Built in Heater Internal heater helps to maintain water temperature at its optimum level for selected cycles Child Lock The child lock prevents children from pressing any button to change the settings during operation SMART DIAGNOSIS TM Should you experience any technical difficulty with your washing machine is capable of producing multiple distinct d...

Page 5: ... the tub drains to a certain level water temperature washing time rinsing time the best washing performance spin rhythm time load size NEURO FUZZY selected washing temperature SENSING EFFECT PROCESSING DETERMINATION The door can be opened by pulling the door handle whenever washer is not in operation When the cycle is completed the DOOR LOCKED light will turn off If a power failure has occurred wh...

Page 6: ...te this function Press and hold thePre Wash button for 3 seconds 2 8 WATER CIRCULATION When washing and rinsing function of shower at the upper part of Gasket When washing it continuously operates for 3 minutes and intermittently When rinsing it continuously operates after completion of water supply 2 9 STEAM For tough stained clothes sick room linens or baby clothes Steam Wash is availablewith Sa...

Page 7: ...ut prior notice for product improvement purposes Parts and Accessories Parts Pedestal sold separately Stacking Kit sold separately Accessories Hot cold water hoses Non skid pads Caps for covering shipping bolt holes Wrench Tie strap Elbow bracket for securing drain hose Water inlets Shipping bolts Power cord Drain hose INCLUDED Accessories OPTIONAL Accessories Detergent dispenser drawer See page 2...

Page 8: ...correctly STANDARD INSTALLATION The appliance should be installed as follows Remove the 4 shipping bolts with the supplied wrench Remove the lower bolts fist It is easier that way Keep the shipping bolts and spanner for future use Insert the 4 caps provided into the hole Turn clockwise to raise counterclockwise to lower Turn the leveling feet to adjust the appliance REMOVE THE SHIPPING BOLTS INSTA...

Page 9: ...tall the inlet hose to correct temperature water tap Otherwise it cause drips on the drawer panel handle and drawer panel HOW TO CONNECT THE INLET HOSE CONNECT THE DRAIN HOSE The end of the drain hose should be placed less than 96 from the floor Make sure that the hose is not twisted Avoid submerging the end of the hose Hot Cold 9 LGE Internal Use Only Copyright 2016 2017 LG Electronics Inc All ri...

Page 10: ...clockwise 5 Check the automatic reverse rotation 4 Check the water supply Check if water is supplied through the detergent dispenser 7 Check the drain and spin functions Power off and the power on Press the SPIN SPEED button Press the START PAUSE button Check the spin and drain functions Listen for a click to determine if the door is unlocking 8 Press the START PAUSE button 9 Water removal If SERV...

Page 12: ...her is operating Cycle Selector Knob Rotate the Cycle selector knob to select the cycle designed for different types of fabric and soil levels Start Pause Use this button to Start Stop the washer 12 LGE Internal Use Only Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes ...

Page 13: ...RINSE This option will add an extra rinse cycle to the selected cycle RINSE SPIN Use this option to rinse detergent from load CHILD LOCK Use this option to prevent unwanted use of the washer or to keep cycle settings from being changed while the washer is operating Wash Temp Spin speed Soil Level Signal Button Select a water temperature based on the type of load you are washing To change the spin ...

Page 14: ...clothing tablecloths Hot Warm Cold Tap Cold High Medium Low Heavy Normal Light Hand Wash Wool Items labeled hand washable Warm Cold Tap Cold Low No Spin Normal Light Delicates Dress shirts blouses nylons sheer or lacy garments Warm Cold Tap Cold Medium Low No Spin Heavy Normal Light Towels Towels Hot Warm Cold Tap Cold Extra High High Medium Low No Spin Heavy Normal Light Speed Wash Lightly soiled...

Page 15: ...ngs from being changed while the washer is operating Press and hold the PRE WASH button for 3 seconds to activate or deactivate The child lock function The child lock indicator will be shown in the display And all buttons are disabled except the ON OFF button NOTE CHILD LOCK lasts after the end of cycle If you want to deactivate this function Press and hold the PRE WASH button for 3 seconds 15 LGE...

Page 16: ...wer than selected because of re supplied water the heating starts again 7 Washing Fuzzy logic decides washing time according to the laundry load water temperature and other factors 8 Drainage A pump motor drains the water from the drum After sensing drained water amount by water level frequency spin starts When a heating course is selected stay cooling process is performed to decrease the water te...

Page 17: ...ocess 15 Last drainage After spin finishes and power is not supplied to motor the drum rotates by remaining spin power If rinse hold is selected the drainage is not proceeded after rinse finishes 16 Disentangling The same as item 9 17 Intermittent spin The same as item 10 18 19 20 21 22 Main spin1 The same as item 11 Main spin2 At the end of a main spin the spin speed will reach the selected rpm R...

Page 18: ...SPIN SPEED SOIL LEVEL WASH RINSE DELAY WASH Turns on all lamps and locks the door 6 1 6 2 7 6 3 18 LGE Internal Use Only Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes ...

Page 20: ...AY PCB ASSEMBLY is cut or not connected open circuited The NFC PCB ASSEMBLY is bad or out of order short circuited The NFC EEPROM is out of order nC is displayed only in the first screen of the Test Mode NFC version is not matched It needs to be exchanged nU is displayed only in the first screen of the Test Mode 8 EEPROM is out of order Displayed only when the START PAUSE button is first pressed i...

Page 24: ...rt of wir e part of moto r Motor Yes No Yes Yes Magnet Replace the STATOR Is the resistance values in the range of 5 to 15 U V V W W V U 1 V 2 W 3 After pull out the RD 4 connector check th e terminal of the connecto r in wire Red 3P male No Replace the MAIN PWB ASSEMBLY Check the IPM in the controller No Is LE ERROR displayed Motor Drive LGE Internal Use Only Copyright 2016 2017 LG Electronics In...

Page 25: ... the DOOR SWITCH ASSEMBLY No Yes Does the spring of Latch Hook actuate Replace Door Assembly Yes No Note Environmental check list 1 The machine must operate with all the doors completely closed and locked 2 The washing area must operate with a water temperature not higher than 45 Celsius and must not have more amount of supplied water than it should Is dE ERROR displayed 25 LGE Internal Use Only C...

Page 26: ...UNBALANCE ERROR OVER FLOW ERROR Note Installation check list WASH RINSE DELAY WASH 26 LGE Internal Use Only Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes ...

Page 27: ...e of the pressure sensor out of range pin 1 pin 3 21 23 Ω 10 Replace the pressure switch No Yes Is the AIR CHAMBER and the tube clogged Replace the MAIN PWB assembly Fix the air chamber and remove the foreign material Yes Is PE ERROR displayed 27 LGE Internal Use Only Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes ...

Page 28: ...ulti outlet power strip enough Avoid connecting several electric devices Is the supplied voltage 120V AC 10 15 Alternate with explanation Yes Yes No Is the connector connected to PCB Noise filter disconnected or disassembled Reconnect or repair the connector No Replace the MAIN PWB ASSEMBLY Yes No Is LED on while the power is on Replace the PWB ASSEMBLY Display PWB Connecting connector MAIN PWB Di...

Page 31: ...Compartment 4 Main Wash Compartment Is the detergent caked or hardened Is water supplied Check the wiring No Are receptacles correctly connected to the terminals of the INLET VALVE ASSEMBLY Put the detergent in the correct place Clean the dispenser Yes Yes No Pre wash Main wash Detergent 1 4 3 2 31 LGE Internal Use Only Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and s...

Page 32: ...rect compartment of the drawer Put it in the correct compartment Clean the cap and container No Yes Yes Yes Secure the bolt Is there friction noise coming from the motor Check stator Replace if necessary Check rotor for broken magnets Replace rotor if necessary Yes No Yes 1 Liquid chlorine Bleach Compartment 2 Liquid fabric Softener Compartment 3 Prewash Compartment 4 Main Wash Compartment 1 4 3 2...

Page 33: ...Tag On guide Tag On position Look for the Tag On icon next to the LED screen on the control panel This is where you position your smart phone when using the Tag On function with the LG Smart Diagnosis Cycle Download and Laundry Stats features of the LG Smart Laundry DW application When you use the Tag On function position your smart phone so that the NFC antenna on the back of your smart phone mat...

Page 34: ...discharge sufficiently WARNING Wiring diagram Circuit in the MAIN PWB Wiring Diagram Vac MAIN PWB ASSE MBLY FUSE RD1 WH1 LI L2 I C I R C2 C3 3 2 1 3 2 1 Test points and Result Test Points Result WH 1 to RD 3 WH 3 to RD 1 0 0 3 1 WH1 3 1 RD1 LGE Internal Use Only Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes ...

Page 35: ... lock is detected when switches in terminal 4 5 are set closed CAM rotation will forcibly clear off the connection The maximum allowable number of impulse authorizations is 2 Upon the third authorization of the impulse the position of CAM goes back to the door open position Authorizing the impulse occurs in 4 5 seconds upon input for max performance and two authorization processes are allowed at m...

Page 36: ... 3 to 4 4 to 5 2 to 4 Result 700 1500 Ω 60 90 Ω Infinity 120 Vac Remarks At 77 F 25 C At 77 F 25 C Voltage Input 5 3 2 4 36 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Internal Use Only ...

Page 37: ...om stopped to maximum speed in infinite steps in either direction There are 36 poles on the stator 12 permanent magnets spaced around the rotor There are no brushes to wear out Unlike a more traditional brushless motor the rotor surrounds the stator rather than being attached to it Test Points Result 1 to 2 2 to 3 3 to 1 5 15 5 15 5 15 WINDINGS 1 2 3 Copyright 2016 2017 LG Electronics Inc All righ...

Page 38: ...MP BK Object Function Test points Result Each circuits of loads in wiring diagram are all same Two pumpmotors are used to drain the tub and to circulate the water detergent solution Drain Pump Drain Pump Circulation Pump Circulation Pump Test Points Result 1 to 2 10 20Ω 38 Test Points Result 1 to 2 18 30Ω T P For Drain For Circulation 1 2 2 1 1 2 Copyright 2016 2017 LG Electronics Inc All rights r...

Page 40: ...iagram Each circuitsof loadsin wiringdiagram are all same Wash Heater Wiring diagram Circuit i n the MAIN PWB Test Points 1 to 2 12 18 Result 40 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Internal Use Only Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Internal Use Only ...

Page 41: ...8 7 THERMISTOR ASSEMBLY Circuit in the MAIN PCB Wiring Diagram 41 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Internal Use Only ...

Page 42: ... Thermistor Test Points 1 to 2 Result tolerance 5 39 5 kΩ 26 1 kΩ 12 1 kΩ 8 5 kΩ 3 8 kΩ 2 8 kΩ 2 1 kΩ 1 4 kΩ 1 0 kΩ 0 7 kΩ 0 4 kΩ Remarks At 86 F 30 C At 104 F 40 C At 140 F 60 C At 158 F 70 C At 203 F 95 C At 221 F 105 C At 241 F 116 C At 266 F 130 C At 293 F 145 C At 320 F 160 C At 356 F 180 C 42 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE In...

Page 43: ... Remove one screw 6 Lift the side the control panel assembly and pull it out 7 Unscrew the 8 screws from the control panel assembly 8 Disassemble the display PWB assembly 9 Disconnect the NFC connector 10 Disassemble the NFC PCB from the PCB assembly display TOP PLATE ASSEMBLY CONTROL PANEL ASSEMBLY DRAWER CONTROL PANEL ASSEMBLY DISPLAY PWB ASSEMBLY 9 DISASSEMBLY INSTRUCTIONS 43 Copyright 2016 201...

Page 44: ...ure switch assembly Remove the protective cover Unscrew 1 screw on the back Remove the main PWB Disconnect the connectors PROTECT COVER 1 2 3 4 5 44 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Internal Use Only ...

Page 45: ...a screw from the top bracket Unscrew the clamp nut at the lower part of the dispenser Unscrew 2 screws from the back of the cabinet Disassemble the 4 connectors from the valves Wire Color Blue Housing YL BK White Housing WH BK Blue Housing GY BK Red Housing BL BK 1 2 3 4 DRAWER 1 3 2 4 5 6 1 2 45 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Inte...

Page 46: ...lter cover Put a flat screwdriver or putty knife into the hinge slots at the bottom of the cover and pry it out Unscrew the screw from the lower side of the cabinet cover 1 2 3 4 46 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Internal Use Only ...

Page 47: ...ctor Disassemble the clamp assembly Disassemble the gasket Lift and separate the cabinet cover NOTE When assembling the cabinet cover connect the door switch connector 5 6 7 8 9 10 11 47 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Internal Use Only ...

Page 48: ...ng the special gasket pliers Unscrew the 2 screws Disassemble the door upward NOTE Reconnect the connector after replacing the door switch assembly 1 3 1 2 2 DOOR DOOR LOCK SWITCH ASSEMBLY 48 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Internal Use Only ...

Page 49: ...Separate 2 connectors from the heater Loosen the nut and pull out the heater CAUTION When assembling the heater insert the heater into the heater clip on the bottom of the tub Tighten the fastening nut so the heater is secure CIRCULATION HOSE PUMP HOSE BELLOWS 1 2 3 1 2 3 49 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Internal Use Only ...

Page 50: ... by inserting a long bar in the opening LAMP ASSEMBLY Unscrew 2 screws on the back of the top plate Pull the top plate backward and upward as shown TOP PLATE ASSEMBLY 1 2 3 1 Disconnect the connector 3 2 Disassemble the lamp assembly 4 50 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Internal Use Only ...

Page 51: ...emble the back cover Remove the bolt Pull out the rotor 1 2 3 Unscrew the 2 screws from the tub bracket Remove the 6 bolts on the stator Unplug the 1 connectors from the stator 1 2 3 Disassemble the damper hinges from the tub and base 1 51 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Internal Use Only ...

Page 52: ...5 A455 A410 A151 A130 A140 A131 A153 A390 A201 A440 A430 A100 A101 A104 A102 F215 F210 A450 A111 A110 A141 A150 A103 A220 A200 M410 A106 F110 A154 A152 A156 A180 A181 040 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Internal Use Only ...

Page 53: ... K130 K530 F464 F310 K117 K141 K142 K121 K122 F468 F145 K340 K344 K345 K342 K550 K540 F461 K520 K135 F360 F365 K611 K610 K349 K571 K572 K570 K105 K190 K516 K111 K115 53 K346 K348 K347 K513 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Internal Use Only ...

Page 54: ... F329 F170 F220 A275 A276 F227 F226 F225 F323 F322 F321 HOT RED COLD BLUE Inlet Valve Filter SVC E G N A R O T O H E U L B D L O C F160 54 F340 Copyright 2016 2017 LG Electronics Inc All rights reserved Only training and service purposes LGE Internal Use Only ...

Page 56: ...69 P No MFL67307921 ...

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