LG Dishwasher SVC Schematic

Page 1

Dishwasher

Service Handbook

Service Handbook LDF6920 + V1 090603 Service Handbook LDF6920 + V5 100525

Model : 24” Built In Dishwasher

Customer Model	Factory Model	Suffix

1.Test mode ( Check electric parts operation )

1.Test mode method …………………………………. 2

2.Electric parts function test …………………………. 3

2.Error mode ( Connecting to Test mode )

1.IE …………………………………………………… 5

2.OE …………………………………………………… 7

3.E1 ……………………………………………………10

4.FE ……………………………………………………11

25. HE ……………………………………………………12

6.tE …………………………………………………… 13

7.LE …………………………………………………….. 14

8PF ( Not error message ) …………………………….15

3.Trouble shooting guide ……………………………….16

1.No power ………………………………………………17

2.Not running ( washing motor ) ………………………19

3.Poor wash ……………………………………………. 21

. White spot, white powder, cloudy glasses

. Soil spot, really not washing/clean

4.Poor dry ………………………………………………25

5.Noise …………………………………………………..28

6.Leakage ……………………………………………….30

4.Exploded view & location number ………………….. 35

Appendix. SVC Bulletin

1)Installation ( Base ) ……………………………………...39

2)Drain hose with siphon protector ……………………..46

3)Hinge rope & spring about door drop …………………49

4)Vent modified for protecting moisture condensing …..51

5)HE error……………………………………………………52

4	6) Air Sucking noise cause by program …………………56 3
	7)	Install improvement for worm gear leg………………….59
5	8)	Poor Washing cause by the defectivc filter asm	…….63
	Service Handbook LDF6920 + V1 090603		Written by Jhe Hyouk Lee
			LG Dishwasher June 4, 2009

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 2

1. Test Mode

Air guide

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 3

1. Test Mode

If we disconnect the wire plug,

Only Auto1(Strong) program is running

Washing motor problem

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 4

1. Test Mode

Open the door

Remove the door

Bottom area

In the sump

•For 10 seconds check the power or current by using probe

( 8A ~ 10A)

-remove junction cover

-contact the probes to Black, White harness wire.

Remove the door

Opposite side

( Soft noise & vibration )

In the sump

.Check the resistance of vario motor

.Check the loose fitting of micro s/w “

.Heavy soil remain around the valve

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 5

2. Error Mode

Micros switch loose connection ( next page )

Check the water supply system ( Parts , sensor , environment ) by TEST MODE – 4 ( Page 1), Test 4 (Page2) Î If there is water flow in & can see the frequency raise : No problem

Î No water flow in or no frequency raise : Problem in water supply system or environment

1) Water supply tap is closed or no water supply CIC

Hose

92) Water supply shut off CIC

.Check the water tap is closed

Î Open

.Check that water supply is ok in this water tap

( Remove water hose, open the water tap a little bit and check the water supply ) If not

ÎChange water supply source

.Check the status of other water tap ( Water supply is ok or not )

3) Water supply hose kinked Î Make not kinked

4)If water supply is ok ( open the door, we can check ) but no frequency raise.

- Water supply pressure is very low ( below 0.3 bar )

Air guide

Flow meter (sensor) Impeller

The water pressure is too low to rotate a impeller for checking Water flow

ÎOpen the water tap fully

ÎChange the water supply source which is high water pressure

- Air guide problem

. Impeller is stuck so not rotate Î Change Air guide

( Disassemble the air guide & blow, can check rotation )

. Flow meter ( sensor ) can not check the impeller rotation

ÎChange Air guide or Flow meter

5)Inlet valve problem ( No water supply, No frequency )

-Loose connection of electric harness wire Î Reconnecting

-Inlet valve filter clogged	-Bad inlet valve
Î Remove filter and	ÎCheck the resistance
clean the filter & valve	( short or cut = 0 or infinite )
assemble the filter	& replacement

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 6

2. Error Mode

6) Micros switch loose connection

What was seen when the panel was removed This is a better view of the disconnected wire

1		2

The unit is now responding to SC test normally			The connector was reinserted back into place
	4			3

	Customer Model	Factory Model	Suffix
	LDF6810XX	D1608

Page 7

2. Error Mode

Garbage disposal plug block the drain flow ( Installation )

too long extension hose ( 6ft )

Float hinge stuck ( Wrong sensing ) can happen in Serial no : 501 ~ 706

Drain pressure drop from the gap in drain cover ,can happen serial no : 612~711

Make a hole at connection area of disposal ~ drain hose

Shorten extension hose less than 6ft

Replace the float assembly or cut 1mm at float guide

Change sump assembly Product (S/NO: 901~ )

Check the water drain system ( Parts , sensor , environment ) by TEST MODE – 3 ( Page 1), Test 3 (Page2)

ÎIf there is water drain & can hear the drain pump operation : No problem

ÎWater remain in the tub or can’t hear the drain pump operation : Problem

91) Water remain in the Tub after installation [Installation]				2) Drain hose kinked by			bad installation [ Installation ]
.Can hear the drain pump operation, but not drain					Side View
Î Check the garbage disposal ~ drain hose connecting
by finger or drive ( + or - )
	Connecting pipe to dishwasher
	Drain hose
	Connecting pipe to house main
	Drain pipe
	Sell the disposal dishwasher
	Drain hose connecting pipe
	Blocking for protecting
	Leakage ( for Non dishwasher
	Customer )
ÎIf the connecting area was block, make a hole for drain
by using – drive & small hammer – circle direction
								If the passing hole
Block
								Is out of the 7”x4”,
					NG		OK	Drain and water
		Pick up block parts						Supply hose will
								Be kinked

Î Make a new hole

ÎDisconnect garbage disposal power and Remove broken block area in the disposal

& power reconnect the disposal

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 8

2. Error Mode

3) Too long extension hose ( over 6ft, installation )

.If the length of extension hose is longer than 6ft, Can not drain water properly

Î Make the length of extension hose shorter than 6ft

Sink pipe

Drain hose + Extension hose

Dishwasher

4) Drain pump problem

( If not 1), 2), 3) check the drain pump )

-Disconnect drain hose form sink pipe or garbage disposal or Air-gap & release the drain hose to big pots ,

Prepare towel for protect floor wet from drain hose

Disconnect	Release drain hose
Garbage disposal

X

-Run the drain pump by test mode – 3 ,or run the any course & Check the water drain ( If there is no operation noise

or not drain )

ÎReplace the drain pump, be careful the assemble direction and 3 points of fastening 3 screws

[ Reference Assembly of drain pump -----

Page ---- ]

5)Float hinge stuck [ S/no : 501 ~ 706, especially 704~706] Symptom : There is no water in the Tub (Drain ok)

But OE happen sometimes

( Sensing error of water drain )

ÎReplace the Float assembly (float cover) or cut 1.5 mm at hinge guide area in float cover ,

but we should pull dishwasher from sink cabinet.

Left side
Float assembly	Float cover

Hinge

View

Air gap	Drain hose				Cut 1.5mm
X	Big Pot or bowl

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 9

2. Error Mode

6) Drain pressure drop from the gap in drain cover ,can happen serial no : 612~711

. Drain pump operation ( No problem )

. We can see some water is drain to drain hose, sometimes Not OE error but too much water remain

. But after drain process, there is too much water remain in the sump assembly ( 800cc ~ 1000 cc)

Water remain near by sump filter hole

Î Replace sump assembly (S/no: 901~, production date is from 2009.1 ~ )

If the Gap between drain pump case ~ drain cover

Is too much, drain pressure would be drop down.

So not drain, too much water remain in sump

Î New ( No gap : S/no 901~ )

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 10

2. Error Mode

E1 means that there is not enough or very little water in the tub ( dishwasher ) Î Generally a lot of leakage or water drain out by siphon effect can display E1

91) Water automatic drain out by siphon effect [ Installation ]

ÎCheck the drain hose, If the end of drain hose location was below than 10”(250mm) or deep into the water pipe,

the water can be drain out automatically and make air sucking

noise [ S/no 901~, we improved this issue by applying siphon protect, but not perfect ]

Lie drain hose on the floor ÎHose position is below

than 10”(250mm)

Drain hose	Change the end of drain hose position
	Over 10” (250mm) and fixing

H

Water pipe

2) Logistic damage ( Inner area broken or leakage )

ÎCheck the damage or leaking in Tub or Bottom sump area. ÎCheck sump after service, miss hose connecting : If the parts are broken, replace the parts, but tub damage, we can’t repair : Reconnecting hose

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 11

2. Error Mode

FE means that water supply can’t stop so there is excessive water in the tub If the over flow float s/w is on and off 10 times, display FE error

ÎGenerally inlet valve and dirty water supply ( tiny particle or steel powder) problem

So ask the customer lock the water tap connecting to D/W, and dispatch service

91) Water condition

Check that there is much steel stain powder or other dirty material in water pipe especially new house or after remodeling This tiny material can block a small hole in inlet valve, if then even though no power supply to inlet valve,

the water supply is going on infinite until locking water tap.

ÎDisassemble water supply connection between water supply hose & water tap

Open the water tap fully, and hold on for 1 minute or until you can see clean water , and assemble again.

ÎDisassemble water supply hose with inlet valve

Open the water tap fully, and hold on for 1 minute or until you can see clean water , and assemble again Î Next : Clean or replace inlet valve [ Next step ]

2) Clean or replace inlet valve ( Recommend replace inlet valve )

OR

Remove filter in inlet valve	Wash inlet valve	Replace inlet valve

	Customer Model	Factory Model	Suffix
	LDF6920XXD	D1608

Page 12

2. Error Mode

HE can be displayed if the circuit of heater has problems ( short or cut off ) ÎNot heating [ S/no 812~ , HE error can be displayed ]

ÎBefore s/no 812, Even though heater has some problem, the main board can not display HE error, so you can check the heater status by checking power supply at test mode [6] for 10 seconds or measure the heater resistance directly.

1) Customer Environment

If the temperature of water supply is very hot (higher than 140F(60 )) or rated voltage is low

Depending on surrounding condition,

dishwasher will display HE error code intermittently

and stop without drain, even though there is no defect in heater assembly.

Replace the PCB Main board without exception (Refer to the Service Bulletin)

2) Heater problem

Check power supply at test mode[6] for 10 seconds or heater resistance If the Heater is open, HE error will occur every cycle.

Î Replace the heater assembly or Sump assembly

Pull D/W from sink cabinet and Replace the heater assembly

Heater assembly	Thermistor	Heater assemble area
		In Sump assembly

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 13

2. Error Mode

tE means that Main board doesn’t check the resistor of thermistor in heater assembly

if only thermistor has problem, change heater assembly. not replace only thermistor

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 14

2. Error Mode

LE means that the main board can not sense the rotation of washing motor

We can check the washing motor operation by using Test mode “2” in page 2 , Test 2 in page 3

Be careful, water supply must be done before running washing motor to protect water seal

1)In test mode , washing motor doesn’t rotate

ÎChange washing motor

After remove bad washing motor , Sump You must check the water seal condition.

If it’s not good! Change sump assembly

! You must see the white grease is in

Water seal

2)In test mode , washing motor doesn’t rotate

ÎChange sump assembly [ Not only Washing motor but also Water seal have problems ]

!Must use new sump gasket for perfect sealing

Don’t use the gasket in old sump assembly, when you change sump assembly

! Must add some lubricant liquid to out area of sump gasket for better replacement ( hand wash liquid detergent or … )

Sump gasket

Sump assembly

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 15

2. Error Mode

PF : This message is not a error message,

Just display the reason of stop washing is because of not dishwasher but sudden power failure

( There was power supply stop in the dishwasher )

Î Open and close the door

or Power off and run D/W again.

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 16

3. Trouble shooting guide

Leakage

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 17

3. Trouble shooting guide

YES

( Next page )

• Check the electric outlet

<1> Reconnect the power connection

Loose connection Under or over sized wire nuts (melting)

Wire spec : UL AWG16

Insulator diameter : Φ 3.12mm (0.123 inch )

Electric conductor diameter :Φ 1.49mm (0.059inch )

<2> Check the electricity is failed or not

BK

WH Green/yellow

Check power supply

<3> Check the electric outlet

Check power supply

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 18

3. Trouble shooting guide

<1> Check the circuit breaker S/W : On / Off

YES

( Next page )

<1> Check the noise filter

Check the power supply

<2> Check PCB main board

Part number is correct ?

( See SVC part lists )

Change Main PCB

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 19

3. Trouble shooting guide

NO

The door is tightly closed

YES

NO

Error message ?

Close the door tightly

Check the latch assembly in door

If you open the door, , the latch is closed position like left

ÎReposition the Latch by closing the Door tightly

Normal operation ( Serial no: 901 ~ 905 )

In cold water supply condition, after water supply process

Heater heat the water to 95F (35 ).

At this time washing motor runs for 1 minutes when the temperature rise up every 9F(5 ) by target temperature.

	Water supply							Y
			Temperature >95F(35 )
		Only Pre wash process				N
YES
		Temperature		70F		79F	88F	95F
		Heater		ON		ON	ON	Off~
		Washing		Off		On for	On for	On~
		Motor				1 min	1 min

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 20

3. Trouble shooting guide

NO

Checking by test

Mode [Chapter 1]

YES

NO

PF

YES

PF is not error mode

Just display there was

Sudden power failure

FE ( Over flow error )

E1 ( Leak or siphon error )

Refer : Chapter 2 – error mode

IE ( No water supply error )

OE ( No drain error )

HE ( Can’t heat : Heater error: S/no 901~ )

tE ( Thermister error :

Can’t check the temperature )LE ( Washing motor error :

Washing motor do not rotate or

Can’t check motor rotation )

Refer :Chapter 1 – test mode Chapter 2 – error mode

NO

<2> Check PCB main board

Part number is correct ?

( See SVC part lists )

Change Main PCB

	Customer Model	Factory Model	Suffix
	LDF6920XX	D1608

Page 21 3. Trouble shooting guide(5/13)

C. Poor wash

			CIC
		White
			Hard water condition
	Soil spot or	spot
			. White spot on glasses, cups, tub
	white spot
			. White powder residue on cups or …
	(Hard water)
			. Cloudy glasses

Soil Spot [Not washing]

Hard water is from the water supply, not the unit. If hard water is causing white film or powder in unit .

1)Install a water softener can solve the problem clearly.

2)– A Run a cycle with an EXTRA RINSE option to minimize the effect of hard water

*~ S/no:906: Choose Extra rinse option Î + 1 rinse process in cycle

S/no:907~ : Choose Extra rinse option Î + 3 rinse process in cycle

* In Lab test +0 default	: Score 0	/ 5
+1 rinse process : Score 3.5		/ 5
+3 rinse process : Score 4.5		/ 5 in Very high hardness

condition ( 400ppm )

2) – B Don’t put too much soap into dishwasher.

Put 0.7~ 1 ounce detergent into dishwasher : OK

Put over 1.4 ounces detergent into dishwasher : Not good (if the customer choose EXTRA RINSE OPTION )

Use glass magic to minimize the side effect of hard water

Glass magic has 20% of Phosphorus (the material of water softener)

ÎPut 2 Tea spoons glass magic into the tub before starting

ÎPut 0.7 ~ 1 ounce detergent into the dispenser

ÎRun a cycle with an EXTRA RINSE option

Use White Vinegal

1)Remove all dishes and silverware from the dishwasher.

2)Only the racks should remain in the tub

3)Place about 1 cup ( 200ml ~ 500ml) of white vinegar into the Lower rack ( Don’t pour the vinegar to the bottom area )

Run a “Normal” cycle and select “Extra Rinse” and

“Sanitary”, then close the door. Do NOT USE ANY DETERGENT