LG LDF7774BB Service Manual Download Page 28

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For Authorized Service Technician

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7. TROUBLE SHOOTING METHODS

Inlet Error

Condition.

Not reached to the normal water level

in spite of 10 min. water supply.

The water is supplied.

Frequency is not increased

The water is not

supplied.

Is the water tap opened?

Open the water tap.

Repair the inlet hose.

Install the pressure pump.

a) Close the water tap.

b) Unscrew the inlet hose.

(Inlet valve side)

c) Clean the filter of inlet valve.

Is the inlet hose kinked?

Is the water pressure

very low or high?

(below 0.5kgf/

㎠

(20bar),

above12kgf/

㎠

(120bar))

Is the filter of inlet valve

clogged by impure water?

Does the water supplied?

Check the frequency of Inlet Water by

the Test Mode.

Is the connector connected to

main PCB assembly disconnected

or disassembled? (NA8)

Is the voltage between connectors

out of range? (NA8 pin1 ~ pin2)

- After remove terminal position

assurance (TPA) of connector,

check the voltage when water is injected.

(The voltage is 2.5V AC (±15%)

Is the resistance vales between

connectors out of range?

(range is over 5MΩ)

(White 8P, Pin1~Pin2)

Reconnect or

repair the connector.

Replace the main

PCB assembly

Is the Inlet sensor operate properly?

Blue 6P 1-2 is 12V

Replace the inlet valve

Inlet Valve 25±5% (Ω)

Yes

Is displayed?

Summary of Contents for LDF7774BB

Page 1: ...HWASHER SERVICE MANUAL BEFORE SERVICING THE UNIT PLEASE READ THIS MANUAL CAREFULLY FOR SAFETY AND CORRECT SERVICES NOTE For Authorized Service Technician MODEL LDF8874ST LDF8764ST LDF7774ST WW BB LDS5774ST ...

Page 2: ......

Page 3: ... EXPLANATION 6 4 PARTS NAME 13 5 PROGRAM CHART 14 6 HOW TO DISASSEMBLE 16 7 TROUBLE SHOOTING METHODS 25 A TROUBLE SHOOTING ACCORDING TO DISPLAYED ERROR MESSAGE 25 B STEAM GENERATOR ERROR MESSAGE 27 C TROUBLE DIAGNOSES AND REPAIR BY SYMPTOM 40 8 INSTALLATION INSTRUCTION 44 9 EXPLODED VIEW 51 CONTENTS CONTENTS ...

Page 4: ... is intended for individuals possessing adequate backgrounds of electrical electronic and mechanical experience Any attempt to repair this appliance may result in personal injury and property damage The manufacturer or seller can not be responsible for the interpretation of this information nor can it assume any liability in connection with its use CAUTION ...

Page 5: ... Steel Control Electronic Rated Power Watt 1 350 Heater Power Watt 1 200 Programs 6 LDS5774 7 Upper Rack Position Adjustable Lower Rack 100 Fold down Water Consumption 6 5 20 5 Normal Power Consumption kWh year 258 Nomal Operating Time min 110 130 Normal Fan Dry System Yes Delay Start Function Yes Auto Off Power Switch Yes Process Monitor Yes Wash Level 5 Racks Nylon Coating Operating Water Pressu...

Page 6: ...shes without the use of a heating element that would increase en ergy consumption STEAM WASHING not available on all models Steam technology pro vides better cleaning performance than regu lar wash systems Steam is the most energy ef ficient gentle care for your finest china and stemware VARIABLE SPRAY SYSTEM Because the water spray alternates between the upper and lower racks all of the power fro...

Page 7: ...tely three seconds To cancel a cycle To cancel a cycle open the door and then press and hold the Delicate and Dual Control Buttons together for approximate ly three seconds The drain pump will activate and the cycle will cancel The display will show dr and the dishwasher will drain the water After the dishwasher is drained the power will turn off If the power is turned on and no cycle has been sel...

Page 8: ...ay arm 5 Close the door to start the cycle Normal This cycle is for normally soiled everyday loads Quick dry This is a shortened cycle that is intended for washing and dry ing recently used dishes or lightly soiled loads During this cycle both spray arms will run at the same time Rinse only LDS5774 This cycle is a quick rinse for dishes that will not be washed immediately This cycle will rinse dis...

Page 9: ... When the dishwasher is powered up the dis play will be blank When the cycle and options are selected the display will show the total estimated time to complete those selections During operation the display shows the re maining estimated operating time The estimated time shown in the display does not in clude delay times for heating water etc If Delay Start is selected the display shows the delay ...

Page 10: ...The delay start time can be set from 1 to 19 hours in one hour increments Child lock The Child Lock feature helps prevent your settings from being changed during a cycle Selecting this feature locks all of the buttons except for the Power button on the control panel This feature does not lock the door To activate the Child Lock 1 Press the Power button 2 Select the cycle and desired options 3 Pres...

Page 11: ...losed 3 TIME N03 Dispenser All LEDs Closed 4 TIME Soil Level Soil Sensor All LEDs Closed 5 TIME Steam Generator Water Level Water Level All LEDs Closed 6 TIME Sump Temp Sump Thermistor All LEDs Closed 7 TIME N07 Steam Generator Inlet Valve All LEDs Closed 8 TIME Pump RPM Drain Pump All LEDs Either 9 TIME Frequency Inlet Valve All LEDs Closed 10 TIME Motor RPM Washing Pump All LEDs Closed 11 TIME U...

Page 12: ...rsion All LEDs are lighting Either LDS5774 Series only Delay Start 1 TIME N01 Fan Motor All LEDs Closed 2 TIME N02 Dispenser All LEDs Closed 3 TIME Soil Level Soil Sensor All LEDs Closed 4 TIME Sump Temp Sump Thermistor All LEDs Closed 5 TIME Pump RPM Drain Pump All LEDs Either 6 TIME Frequency Inlet Valve All LEDs Closed 7 TIME Motor RPM Washing Pump All LEDs Closed 8 TIME Un Cr LO Vario valve Al...

Page 13: ...WER BUTTON 20 FILTRATION SYSTEM SignaLight front display When a cycle is running the SignaLight will illuminate for the active stage Model with 4 LEDs WASH RINSE DRY CLEAN Models with 2 LEDs OPERATING CLEAN Models with 1 LED OPERATING Flickering CLEAN Lighting Once the cycle is complete the CLEAN light will illuminate for four minutes To keep the CLEAN light on until the door is open turn the powe...

Page 14: ...For Authorized Service Technician 14 5 PROGRAM CHART SCHEMATIC DIAGRAM LDF8874 LDF8764 Program Chart ...

Page 15: ...For Authorized Service Technician 15 LDF7774 LDS5774 Program Chart ...

Page 16: ...ishes and items in the dishwasher 4 Remove the Lower Rack and the Upper Rack 5 Remove the inlet hose and drain hose connetion to avoid the hose damages 6 Prepare some towels to avoid floor wet by the water left in the dishwasher 7 HOW TO DISASSEMBLE 7 1 FULL DISASSEMBLE 1 Lower Cover and Lower Felt 1 Remove the front 2 screws 2 Remove the Inlet Hose and Power Supply Cable 2 Tub Felt 1 Tub Felt Low...

Page 17: ...mbly 1 Front Cover Open the door Remove 2 screws at the bottom 2 Control Panel Assembly Remove 2 screws Stainless Remove the wire connections Be sure the wiring should not be changed in reassembling Remove the Latch assembly Remove the Front Display Remove 8 screws for Controller Remove 12 screws stainless LDF Series ...

Page 18: ... screws at the bottom Remove 6 screws stainless 2 Control Panel Assembly Remove 8 screws Stainless Remove the wire connections Remove the Latch assembly Remove 7 screws for Controller Be sure the wiring should not be changed in reassembling Control Panel Front Cover Controller Controller Latch Assembly ...

Page 19: ...r counterclockwise 4 Detergent Dispenser Close the door Remove the wire connections Remove 6 screws with brackets Push the Detergent slowly pulling up the the Flange by Standard Screwdriver 5 Door Spring Right Left Push the Spring upwards and take it off from the the slot Be careful not to be injured by the sharpedge of Tub Take off the Hinge Link from the Hinge 6 Door Liner Open the door Pull the...

Page 20: ... holder hook as shown in figure 2 Remove 4 screws 3 Hold the lower frame by one hand Push the base cabinet inside from other hand Pull the lower frame out 5 Tub Assembly 1 Rack Remove the top rack and the upper lower rack 2 Nozzle and Water Guide Pull up the nozzle Remove the water guide form the tub bracket Top Rear ...

Page 21: ...onnections Remove 2 hoses assembly Rotate 2 holders between sump and tub Lift up sump assembly Remove the wire connections in the back of the sump assembly 4 Air guide Nut Turn the air guide nut counterclockwise Special tool might be needed 5 Tub Sub Assembly Remove Side 4 screws Remove rear 4 screws Disconnect 1 hose assembly of left side Steam nozzle hose Lift tub assembly upward 3 Sump Assembly...

Page 22: ...echnician 22 18 18 7 Holder Supporter Tub Packing and Hinge Supporter Assembly Rotate the screwdriver after slide it into the gap between Stopper Roller and Rail Roller Remove side 4 screws Push the steam nozzle 6 Steam Nozzle ...

Page 23: ... 23 20 20 8 Rear Leg Adjustment System Remove 2 screws Pull the Holder Pull the Leg Adjust Pull the Shaft Assembly Holder Leg Adjust Shaft Assembly Shaft Assembly 7 Foot Nut Pull the Foot twisting Pull the Nut pushing the hook Nut Foot ...

Page 24: ... Pressure Switch and Soil Sensor 3 Impeller Washing Motor Remove 4 screws 1 hose assembly Lift up pump assembly Remove 6 screws Remove 1 screw under a motor Lift up 2 pump cases Remove 1 screw Lift up impeller Remove 1 screw under a motor Lift up pump cover 21 21 4 Vario Valve Remove 6 screws on the nozzle holders Lift up nozzle holders Lift up Vario Valve 5 Vario Motor Vaio Cam Remove 2 screws fo...

Page 25: ...move the cause of kink or block Check the wiring connection Measure the electric resistance of Drain Motor 20 40 Replace the Drain Motor or repair Remove all the water remained in the drain hose that is connected to the drain pump motor Keep the unit upright don t lay it down Cautious about leaking on the floor Clean the air gap Remove knock out plug the Circuit Replace the connections of Hose Che...

Page 26: ...r is sup plied than normal water level Automatically drain Pump operated EXCESS ERROR displayed Condition The resistance of ther mistor not normally out put THERMAL ERROR displayed Condition Check the wiring connection Replace the cause of restriction Replace the Washing Motor Replace the PCB The Motor is working abnormally MOTOR ERROR displayed Condition The Circuit of Heater is troubled The Ther...

Page 27: ...level sensor and thermistor check Check the inlet valve and sensor connection Check the heater and thermistor SE0 SE1 SE3 SE4 ERROR MESSAGE CONDITION REMEDY Steam Generator Error mode is not displayed in normal condition and it can be confirmed by following additional operation To confirm steam generator error press the SPRAY and HALF LOAD buttons simultaneously When Steam Generator is out of orde...

Page 28: ...0bar Is the filter of inlet valve clogged by impure water Does the water supplied Check the frequency of Inlet Water by the Test Mode Is the connector connected to main PCB assembly disconnected or disassembled NA8 Is the voltage between connectors out of range NA8 pin1 pin2 After remove terminal position assurance TPA of connector check the voltage when water is injected The voltage is 2 5V AC 15...

Page 29: ...move terminal position assurance TPA of connector check the voltage when water is drained The voltage is over 12V DC Is the resistance vales between connectors out of range range is 4 5Ω Yellow 3P pin1 pin2 pin3 Is the connector connected to drain motor disconnected or disassembled Reconnect or repair the connector Replace the main PCB assembly Replace the drain motor Reconnect or repair the conne...

Page 30: ... Yes Yes Yes Water is not flooded in the base Is the float assembled properly Replace or repair the float Tilt the machine and drain water in the base And find the cause of leakage Remove the cause of leakage Is the water flooded in the base How to check Disassembly the lower cover Water is flooded in the base Is or displayed ...

Page 31: ...ange NA8 pin1 pin2 After remove terminal position assurance TPA of connector check the voltage when water is injected The voltage is 2 5V AC 15 Is the resistance vales between connectors out of range range is over 5MΩ White 8P Pin1 Pin2 Does the inlet valve working properly damaged or operating abnormally Replace the inlet valve Reconnect or repair the connector Replace the main PCB assembly Is th...

Page 32: ...sembled RD6 Is the connector connected to heater assembly disconnected or disassembled Is the thermistor operated properly range is 12 13kΩ Is the resistor between connectors out of range RD6 pin2 pin3 After remove the connector from the PCB check the resistor range is 12 13kΩ Reconnect or repair the connector Reconnect or repair the connector Replace the thermistor Replace the main PCB assembly I...

Page 33: ...ance Measured properly range is 11 12 5Ω Does the inlet valve working properly damaged or operating abnormally Is the connector connected to main PCB assembly disconnected or disassembled X1 stand by relay X2 Sump Heater relay RD6 Thermistor When door is closed check the resistor between X1 4pin and X2 4pin Reconnect or repair the connector Reconnect or repair the trans cable Is displayed ...

Page 34: ...es No Does the PCB assembly working properly When door is closed check the resistor between X1 4pin and X2 4pin Heater working 120V AC 15 Heater stop 0 1V Is the pressure S W operating properly Replace the pressure S W Replace the PCB assembly ...

Page 35: ...Is the voltage between connectors out of range WH4 pin1 WH4 pin4 After remove terminal position assurance TPA of connector check the voltage when just power on The voltage is 8 15V Is the motor blocked Remove the cause of block or replace the motor Replace the main PCB assembly Check or replace the motor Replace the motor Reconnect or repair the connector Replace the main PCB assembly Is the resis...

Page 36: ...assembled BL4 vario motor NA8 Vario S W sensing Does the vario S W assembled properly Is the vario motor operated properly range is 12 15K Ω Reassemble vario S W Replace the vario motor Reconnect or repair the connector Does the PCB assembly working properly When Door is closed check the voltage between BL4 pin1 and BL4 pin4 Vario motor stop working 120V AC Vario motor stop stop 0 1V Is displayed ...

Page 37: ...tor Replace the main PCB assembly Reconnect or repair the connector Is the connector connected to PCB Noise filter disconnected or disassembled Is LED on while the power is on Check the fuse or reset the circuit breaker Alternate with explanation Replace the display PCB assembly Is the current rating of multi outlet power strip enough Avoid connecting several electric devices Is nine pin wire of d...

Page 38: ...s not satisfactory Top basket Using a wash booster will help remove spots residue and hard water white film Reduce the amount of Rinse aid a Wash filter assembly b Check the rotation of spray arms lower upper top nozzle a Does the upper nozzle fit properly to the water guide Reassemble or replace the upper nozzle or water guide b Does the water guide fit properly to the sump Reassemble or replace ...

Page 39: ... the upper nozzle or water guide b Does the water guide fit properly to the sump Reassemble or replace the water guide a Does the top nozzle fit properly to the water guide Reassemble or replace the top nozzle or water guide b Does the water guide fit properly to the sump Reassemble or replace the water guide After washing is there water drops on the dishes or inner tub Is the drying result of cup...

Page 40: ... or Circuit Breaker of house is O K The Power Switch or the Circuit is O K Re connect the Powr connection Check the electricity is failed or not Replace the Fuse or Circuit Breaker of house Check the Power Switch or the circuit and repair it Check the Controller Power Circuit C TROUBLE DIAGNOSES AND REPAIR BY SYMPTOM NO NO YES YES YES NO ...

Page 41: ...d The Wiring connections is OK The Blade is not locked by a small and sharp object close the Door tightly Check the Door Switch in Latch Handle Re connect the wiring connections related to the Washing Motor Remove the cause of lock or replace the Blade Replace the Wahing Pump Motor NO NO NO YES YES YES ...

Page 42: ...detergent Correctly used or not Filters clogged or not the holes of spray arms blocked or not Utensils are correctly arranged or not Utensils are overloaded or not the spray arm rotating is obstructed or not the program is correctly selected or not Reduce the amount of Rinse Aid for Streak YES Dry Results are not satisfactory Increase the amount of Rinse Aid Set the number higher Select the Progra...

Page 43: ...ervice Technician 43 28 28 Power Button not automatically off after operation Check the button is blocked by foreign materials Check the Power Switch Replace it if necessary Check the Controller Replace it if necessary ...

Page 44: ...and an adjacent a wall Ensure the floor under the dishwasher is at the same level as the rest of the room to allow for any service requirements If dishwasher will sit directly on subflooring subfloor should be sealed with a waterproof paint or sealer to prevent damage from steam Drill a 1 1 2 38mm dia hole or cut out for drain hose inlet hose and electrical cables on either side approx 4 100mm W X...

Page 45: ... by a qualified electrician No other appliance shall be connected to the same outlet by a double adapter or similar plug 4 The wiring or cord must be oriented as shown in Figure A below 5 Check the dishwasher for any damage before trying to install it 6 Make sure water line and Electrical line are oriented in the bottom channels as shown in the figure below If you find any damage to the dishwasher...

Page 46: ...ater line the house supply should be shut off 4 The Water Supply Tube must be oriented as shown in Figure A on page 6 Step 4 PREPARE DISHWASHER FOR INSTALLATION 1 Adjust the legs to the required height to fit properly under the countertop as shown below 2 Check the level of dishwasher by using level Left side turn the adjusting screw counterclockwise to lower the leg and raise the rear of the dish...

Page 47: ...efore sliding the dishwasher into the cupboard opening make all necessary height adjustments using the legs 3 Slide the dishwasher into the cabinet opening carefully Make sure that the drain hose inside the cabinet is not kinked 4 Follow the instruction as in Figure B Step 5 INSTALL THE DISHWASHER IN CUPBOARD ...

Page 48: ...wn here for connection the drain hose The drain connection must meet local plumbing regulations The S trap spigot must be drilled out cleanly and free of obstruction to its maximum internal diameter if used for drainage To prevent syphoning one of the following instruction methods must be followed Follow local codes and ordinances Do not exceed 10 ft 3m distance to drain Do not connect drain lines...

Page 49: ... make sure that the line is not kinked or sharply bent Inlet Valve Water Supply Tube Elbow 1 Before beginning turn off electrical power to the unit at the circuit breaker 2 Remove the Junction Cover and then Install the Strain Relief 3 Twist Wire Connectors tightly on the wires Wrap each connection with Electrical tape 4 Check again and make sure that all wires are connected correctly black to bla...

Page 50: ...9 FINAL CHECKS 1 Turn electrical power back on at the circuit breaker 2 Turn house water supply back on 3 Operate the dishwasher through one cycle Quick cycle is recommended to check for water leaks and operating conditions 4 Replace the Lower Cover ...

Page 51: ...or Authorized Service Technician 51 10 EXPLODED VIEW 9 EXPLODED VIEW Printed materials Description Owner s Manual Energy Label Loc No Service Manual G001 G002 G004 The following parts are not illustrated ...

Page 52: ...For Authorized Service Technician 52 37 37 EXPLODED VIEW A130 E005 M050 M051 M053 A040 F001 E005 E010 F101 A003 M054 M052 LDF8874 EXPLODED VIEW ...

Page 53: ...For Authorized Service Technician 53 37 37 EXPLODED VIEW A130 E005 M050 M051 M053 A040 F001 E005 E010 F101 A003 M054 M052 LDF8764 EXPLODED VIEW ...

Page 54: ...For Authorized Service Technician 54 LDF7774 LDS5774 37 37 EXPLODED VIEW A130 ACCESSORIE S E005 M050 M051 M053 A040 F001 E005 E010 F101 A003 M054 M052 EXPLODED VIEW ...

Page 55: ...XPLODED VIEW TUB ASSEMBLY F011 F013 M006 F011 F013 F040 F060 F050 F022 F041 F230 F300 F144 F132 F143 F171 F110 F113 F112 F113 F210 F111 F117 F111 F118 F117 M070 M071 F215 F117 F105 F117 F137 F138 F166 F165 LDF8874 EXPLODED VIEW TUB ASSEMBLY ...

Page 56: ... EXPLODED VIEW TUB ASSEMBLY F011 F013 M006 F011 F013 F040 F060 F050 F022 F041 F144 F132 F143 F171 F110 F113 F112 F113 F210 F111 F117 F111 F118 F117 M070 M071 F215 F117 F105 F117 F137 F138 F166 F165 LDF7774 LDS5774 EXPLODED VIEW TUB ASSEMBLY ...

Page 57: ...Service Technician 57 38 EXPLODED VIEW TUB ASSEMBLY F011 F013 M006 F011 F013 F040 F060 F050 F022 F041 F144 F132 F143 F171 M070 M071 F215 F117 F105 F117 F137 F138 F166 F165 F230 F300 LDF8764 EXPLODED VIEW TUB ASSEMBLY ...

Page 58: ...For Authorized Service Technician 58 EXPLODED VIEW BASE ASSEMBLY M260 F149 A160 M090 M500 F046 F047 M210 M266 M105 M100 F148 LDF8874 LDF8764 EXPLODED VIEW BASE ASSEMBLY ...

Page 59: ...For Authorized Service Technician 59 39 39 EXPLODED VIEW BAS E ASSEMBLY M260 F149 A160 M090 M210 M266 M105 M100 F148 LDF7774 LDS5774 EXPLODED VIEW BASE ASSEMBLY ...

Page 60: ...ized Service Technician 60 A165 A159 A080 A155 A156 A151 A157 A158 A145 A141 A147 A146 A142 A101 A102 A103 A150 A110 A140 A070 A060 F191 F192 F004 F005 A050 EXPLODED VIEW RACK ASSEMBLY EXPLODED VIEW RACK ASSEMBLY ...

Page 61: ...For Authorized Service Technician 61 EXPLODED VIEW CUTLERY RACK ASSEMBLY A170 A171 A172 A152 LDF8874 LDF7774 LDS5774 EXPLODED VIEW CUTLERY RACK ASSEMBLY ...

Page 62: ...zed Service Technician 62 LDF8874 LDF8764 LDF7774 EXPLODED VIEW PANEL DOOR ASSEMBLY K260 K207 K270 K280 K215 K280 K251 K254 K222 K230 K005 K010 K030 K100 K110 K121 K124 K002 F174 F142 F141 K140 K141 K001 K122 K101 ...

Page 63: ...r Authorized Service Technician 63 K200 K212 K006 K262 K260 K254 K K030 K217 K002 K001 K122 K110 K121 K101 F174 F142 F141 K124 K140 K100 K141 K252 K280 K251 EXPLODED VIEW PANEL DOOR ASSEMBLY LDS5774 K222 ...

Page 64: ...For Authorized Service Technician 64 M130 M060 M081 M071 M074 M120 M025 M087 M031 M028 M026 M088 M027 M072 M070 M006 M125 M126 M075 M091 M089 M030 M131 M134 M133 M132 A120 EXPLODED VIEW SUMP ASSEMBLY ...

Page 65: ...BL4 RD to BL WH1 RD1 Noise Filter 0 Ω WH1 WH to RD1 BN WH1 BK to RD1 BK 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 11 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 11 10 9 8 7 6 5 4 3 2 1 NA9 1 2 3 4 5 6 1 2 3 4 5 6 LED Supporter 6 5 4 3 2 1 NA6 10 9 8 7 6 5 4 3 2 1 GN YL OR RD BN BK BK BN RD OR YL GN BL VT GY WH Power Button BK BN RD OR YL GN BL VT GY WH PK Pressure S W Pressure S W NOTES ...

Page 66: ...9 1 2 3 4 5 6 1 2 3 4 5 6 NA6 Pressure S W Pressure S W Wiring Color Legend BK Black BL Blue BN Brown GN Green GY Gray OR Orange PK Pink RD Red SB Sky Blue WH White V Violet YL Yellow Function Test while operating Press Auto Dual Control Water Temp Press Auto Heavy Water Supply Frequency Press Dual Control Heavy Wash Motor RPM Press Quick Dry Extra Dry Drain Motor RPM Press Dual Control Normal Var...

Page 67: ...For Authorized Service Technician 67 ...

Page 68: ...For Authorized Service Technician 68 P No MFL37554813 ...

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