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Device and repair of the electronic module of thewashing machine LG WD-80160 series with thecollector Intellowasher drive motor

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CM "LG WD 80160" is composed of two electronic module - cost control and display, as well as the basic module. The main module is the variety, such 6871EN1032D and ELAN-PJT6870EC9090-1. Thesemodules are basically different layout and marking of electronic components, there are also somedifferences. On the example of the module ELAN-PJT6870EC9090-1 consider its circuitry features andcharacteristic fault.According to the destination module ELAN-PJT6870EC9090-1 functionally no different from similardevices from other manufacturers. But it also has its own characteristics, which we shall discuss below.

The appearance of the electronic module ELAN-PJT6870EC9090-1 shown in Fig. 1.

External wiring of the module is shown in Fig. 2. It should be noted that in this figure shows a connectiondiagram relating to a different version of the module.

Fig. 2. Connection diagram CM "LQ WD 80160" with the electronic module 6871EN1032DOne difference is in the pin assignments of the connector NA (NA6), it is shown in the table.


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Fig. 3. Location of components on the module ELAN-PJT6870EC9090-1 (upper side)

Location and designation of the main elements on the module ELAN-PJT6870EC9090-1 shown in Fig. 3(upper side) and 4 (reverse side).

Fig. 4. Location of components on the module ELAN-PJT6870EC9090-1 (lower side)

Note that the appointment of the external connectors of the module will not be considered separately,since this information is graphically illustrated in Fig. 2 and 3.Basic functions of electronic moduleview electronic module performs the following functions:- exchange of information with the board display and control;- control the water level in the tank (actuators are valves for water tank and the drain pump and the controlfunction performs a level sensor);

Pin assignment of the connector NA (NA6) for different versions of the basic module CM "LG WD80160"

Pin Number

The pin assignment for the module6871EN1032D ELAN-PJT6870EC9090-1

1 General Input for connecting a temperature sensor

March 2 Inputs for connecting tachosensor Inputs for connecting the water levelsensor

4 Input for connecting a temperature sensor Login to connect tachosensor

June 5 Inputs for connecting the water level sensor General- Control of the device lock hatch (UBL)

- heating control of water in the tank to a predetermined temperature (actuator serves heater, controlfunction performs temperature sensor);


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- The drive motor in all operational modes (reverse mode - in the wash, with speed control - duringthe spin cycle). Adjusting the engine speed is based on the PWM terminal regulatory element is thevelocity of rotation of the motor is provided by tachosensor.

Structure and main chain

We list in the modules and components of the basic elements, consider the purpose and the main chain oftransmission signals. Schematic circuit diagram of main units of the module shown in Fig. 5-7 and Fig. 10-14.

Fig. 5. The electrical circuit. The microprocessor, EEPROM, reset circuit, a clock signal generatorfrequency of 100 Hz

Fig. 6. The electrical circuit. Power supply, relay and switching phase of PETN

As part of the module are the following elements and components:- microprocessor IC1 type TMR87RM41F firms TOSHIBA (Fig. 5). It is a major component of the controlmodule. The microprocessor is an 8-bit nucleus embedded RAM and ROM of 1 and 32 Kbytes,respectively, and the 10-bit 16-ca-nal ADC 2-channel PWM, 16-, and 8-bit timers, a watchdog timer, and

others. It is made in a 64-pin package QFP64-P-1420-1.00A. The efficiency of the microprocessor in thismodule provides the initial reset circuit on the chip type IC8 7042AR (its output is connected to the pin. 23IC1), quartz crystal CRT 8 MHz (connected to the pin. 24, 25 IC1) and the amplifier-shaper clockfrequency of 100 Hz transistor Q91 (the output of this stage is connected to the pin. 11 IC1, the inputsignal is removed from the diode bridge D81-D84).


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Note that, depending on the software stored in masked ROM processors assigned some of his conclusionsmay be different. Pin assignment processor will be discussed in more detail with respect to the mainmodule circuits.- EEPROM (EEPROM) type 93S46 (Fig. 5). The chip has a 64x16-bit organization is formed in the bodySOIC-8 and communicates with a microprocessor on a 4-wire serial bus. Memory chip is used to storevarious ancillary data (eg, fixed the error codes or intermediate data of operations selected wash program),so if its possible replacement can install new firmware without EEPROM (with codes FF).- Power Source (IP) (see . Fig. 6) serves to generate DC voltages of 16 V (non-stabilized), 5 and 12(stabilized), and the voltage pulse frequency of 100 Hz to the timing of the internal timers of themicroprocessor in the composition IC1. The structure of SP includes the following elements: power transformer (TRANS). On its secondary winding is formed alternating voltage of 16 V,rectifier and filter (D81 -D85, R84, C82, C84);

stabilizer and filter 12 (IC7 7812 and C82),stabilizer and the filter 5 (IC6 7805, C81, SE81).

Fig. 7. The electrical circuit. The control board and display control circuit from the microprocessor

IC1


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Fig. 8. Block diagram of the integrated assembly ULN2004A

Fig. 9. Schematic diagram of one channel of the integrated assembly ULN2004A

- 7-channel integrated transistor switches IC2, IC3 type ULN2004A. They are used as buffer elements inthe control circuits relay coils and triacs. Furthermore, ULN2004A (IC11) is a part of the control boardand display as a buffer generator matrix rows display (see. Fig. 7). Note that as part of this board there is

another 8-ka-functional keys M54563R assembly. It performs the function of the column amplifier matrixdisplay.The block diagram of the chip ULN2004A is shown in Fig. 8, a schematic diagram of one channel of thechip part - in Fig. 9.


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Fig. 10. Schematic diagram of connections between the microprocessor IC1 and integrated transistorswitches IC2, IC3

Fig. 11. The electrical circuit. Managed generator water level sensor signal amplifier tachosensorFigure. 10 is a diagram of connections between the microprocessor IC1 and IC2 assemblies, IC3.

- Run the generator water level sensor. Generator (Fig. 11) is based on three valves comprising the

assemblage of Schmidt triggers IC4 (4069UBF). The level sensor includes a coil and a core which movesalong the axis of the coil during the deformation of the diaphragm, perceiving the change of pressuresupplied thereto. In turn, this pressure is dependent on the water level in the tank. Actually, we obtain asystem that converts the value of the water level in the tank frequency. The signal from the level sensor


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controlled oscillator is fed to the pin. 43 microprocessor IC1. More information about the sensors of thistype can be found in [4].

- Chain signals tahogenera torus. Tachometer presents! a coil which acts an annular permanentmagnet mounted on the shaft of the drive motor. It serves to generate signals, the repetition frequency ofwhich is proportional to the rotational speed of the motor shaft. Tacho signal comes through the chain: the

pin. 4 connector NA6 - pin. 2 and 1 amplifier chip composed IC9 (KIA538) - R71 - pin. 44 IC1 (Figure11).- Circuit interlock devices hatch (UBL) and the power of PETN. Microprocessor with the pin. 5 generatesa signal lock hatch, which then flows through the circuit: the pin. 5 and 12 assembly IC2 - relay H111 -UBL (see. Fig. 3, 12). To control the actuation UBL provides the following circuit: contact D / Sconnector NA3 (Fig. 3, 12) - driver (R102, R103, SD101.C101, SE101) - CONCLUSIONS. 52IC1.Power to the heater is supplied through the relay contacts H144 and H145. The relay is controlled by

H144 Chains pin. 12 IC1 - pin. 2 and 15 of IC3 - relay H144 and H145 - the chain: the pin. 10 IC1 - pin. 4 and 13 of IC3 - relay H145 (Fig. 6).The relay H111 - type NAIS AQ1V-12V (UHOM = 12B, UKOMM MaKC = 250B, Ik0MMmaks = 1 A)and H144, H145 - type NAIS ALE16B12 (UHOM = 12 ,Ukomm max = 250 V, I, kommmaks = 16 A)- Control unit drive motor. Detail of the concept of the module with the elements of the control circuitdrive motor shown in Fig. 13.

Fig. 12. The electrical circuit. Drain pump control circuit iUBL


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Fig. 13. The electrical circuit. Control circuit collector drive motorView electronic module is designed to work with the collector DC drive motor. The motor is powered

by a separate rectifier, stator and rotor windings are connected in series. Counter rotation mode in this caseis achieved by changing the phasing-ki turn stator winding by a relay. Smooth control of motor rotation

provides PWM regulating element on the triac. Speed control motor provides the microprocessor withtachogenerator.The node control drive motor includes the following elements:

Reversing relay drive motor XI31, XI33. They are used to change the phase of the stator winding of themotor switch (for the reverse rotation of the drum in the SM mode washing). The relay is controlled by the

microprocessor according to the following circuit (in brackets for relay circuit H133) pin. 3 (6) IC1 - pin. 7(4) and 10 (13) IC2 - relay coil H131 (H133). Both relay - type OMI-SH-112L (UHOM = 12B,Ukomm max = 250 Ikommmaks = 12 A

relay switching of the stator windings of the drive motorXI32. Since the stator having two windings, this switch provides its switching modes in washing andspinning. Relay coil is controlled by a microprocessor circuit, similar to relay H133 (See above.). Relaytype H132 - OMI-SH-112L;rectifier drive motor. He made the diode bridge type GSIB15A60 (Imax = 15 A, Vmax = 600 V) and filter

elements S131.S133, R131; Managing the triac drive motor. Triac type BCR16PM TR116 is connectedin series to the power supply circuit of the motor and provides smooth control of its revolutions. Triaccontrol signal from the microprocessor via a key consisting of IC2 and the resistor R123. To monitor

performance in B thermistor circuit is the following: CONCLUSIONS. A2 triac TR116 - rectifier-shaper(R162, R163, SD161, SD162, C161.SE161) - CONCLUSIONS. 53IC1. In the power supply circuit of thedrive motor is also included thermal relay - put it on the motor housing and breaks the circuit when the setof critical temperature.- The control circuit drain pump. Detail circuit diagram of the electronic module, which shows the controlcircuit of the drain pump is shown in Fig. 12.The drain pump is controlled by the circuit: the pin. 7IC1 - pin. 3 and 14 of IC2 - R21 - Triac TR115(BCR8P) - contact DP connector NA3 - drain pump.


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Fig. 14. The electrical circuit. Control circuit valves for water tank

- Control circuits valves Gulf waters. Detail of the concept of the electronic module, which shows thecontrol circuit of the Gulf water valves, shown in Fig. 14. The valve is controlled by the followingcircuits: the main wash valve: CONCLUSIONS. 8, 9IC1 - pin. 1, 2, 15, 16, IC2, R120 - Triac TR114(BCR1AM12) - contact MV connector BL1 - coil valve for water tank; valve separating prewash:CONCLUSIONS. 12 IC1 - pin. 3 and 14IC3 - R1119 - Triac TR113 (BCR1AM12) - contact PV connectorBL1 - coil valve Gulf waters. - Temperature sensor circuit. The temperature sensor (thermistor NTC) isused to control the water temperature in the tank see. The signal from it in the form of a DC voltage issupplied by the circuit pin 1 of the connector NA6 - filter (SE61, R61, C61) - CONCLUSIONS. 50IC1(ADC).

Features of repair of the electronic module

As you know, most electronic modules CM LG (except for control and display boards) are placed in a plastic casing and filled special silicone sealant. Naturally, when there is a need to repair the modulesealant impedes access to the electronic components.This can be solved by removing the module from the housing and the subsequent removal of the sealant onthe outside or back side of the board.Simplistically similar process can be divided into the following steps:

- On the inner perimeter of the housing with a small flat screwdriver to clean the edges of the board ofthe sealant;- thin screwdriver to deepen the groove on the perimeter boards in the gap between it and the casing;- insert a thin flathead screwdriver between the board and the housing in one corner near the powertransformer. Gently lift the corner and gradually the whole board is removed from the housing in a

direction from the transformer to the opposite narrow side. Home - a caution not to damage the board andelectronic components thereon,- after removing the card from the jacket is removed from its sealing in the places where it is needed. Inorder to prevent damage to the components on the board is better to remove sealant wooden spatula orsimply with your fingers;


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- after repair sites boards with which the sealant has been removed, you must cover the protective varnish,for example PLASIK 70 (for installation works). Incidentally, this lacquer is removed from the board bymeans of soldering station.

Note. Experienced repairers already on the external signs of the fault known elements on the module youwant to check first. They are not entirely removed from the housing unit, and cut in the plastic casing(back of card) areas that provide access to printed wiring interest components. One such example isconsidered in [3].

Fig. 15. The quality of the solder contacts of the relay in the old (a) and new (6) versions of theelectronic modules

In most electronic modules CM LG often fail due to bad relay solder joints their power circuits (so-called"cold soldering" contacts). It should be noted that the manufacturer has considered complaints repairorganizations on this issue. For example, a recently revised version appeared modules for CM "LGWD-10160 (N / S)" and "LGWD-10180 (N / S)" with reinforced solder joints power components. These boardshave a yellow sticker with the word "IMPROVED". Figure. 15 shows the quality of the solder contacts ofthe relay old (fragment a) and new (fragment b) versions of electronic modules.Typical failure of the module and how to resolve themat the front of the SM error code dE (not closed hatch door)If you encounter this error in the first place check Relay H144, H145, and their rations, and UBL, itsconnectors and relays H111. To check the specified relay and soldering quality of their conclusions must

be removed from the board of the plastic cover (See above.) Or cut a hole in the casing to be available print area of contact of the relay. The front panel of the SM error code tEThis error means that the resistance value of the temperature sensor is out of tolerance or the watertemperature does not match. Usually in such cases, the temperature sensor is checked (the resistance at 20

C should be approximately 15 ohms) and its circuits, as well as PETN (25 ... 28 ohms).If the temperature sensor is normal, it is necessary to check the module component values in its chain(from pin 1 of the connector NA6 to the pin. 50 IC1): R61, R62, C61 and SE61. Also check theserviceability of the elements in the food chain of PETN (see. Description).In sum, we note that the main cause of failure of such electronic modules is "cold soldering" relay in the

power supply of PETN and UBL, relays themselves are also often fail. It can be said, a kind of "callingcard" in the statistics of the fault most modules CM LG.When trying to restore these modules exacerbate the problem of difficulty with access to the electroniccomponents of the fee due to the applied layer of sealant on them.As for the general statistics of faults like CM , it differs little from the products of the same class and pricerange of other manufacturers. We note only that in CM LG often fail heating elements, and in machines

with direct drive - tacho based on Hall sensors.Identify the faulty components and assemblies CM LG with electronic control for experienced repairersusually is not difficult, as these machines have a developed system of internal diagnostics - test mode anddisplay error codes.

Literature


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1. Features of the service of washing machines "LG Intellowasher". "Repair & Service", 6, 2004.2. Washing Machine LG: Diagnostic mode and error codes. "Repair & Service", 4, 2007.3. From experience repairing washing machines. "Repair & Service", 5, 2008.4. Inductive sensors water level of washing machines. "Repair & Service", 6, 2008.

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