Repair of the electronic module of the LG washing machine

The electronic module is a common culprit when your LG washing machine acts strangely. This essential component regulates everything, including the water levels and wash cycles. If this electronic part isn’t functioning properly, it might be time to fix your machine.

Gaining insight into the function of the electronic module will enable you to identify problems more precisely. It’s basically the washing machine’s brain, and when it breaks down, your whole laundry schedule can be upended. But don’t worry, it doesn’t have to be a difficult task to replace or repair.

We’ll go over the typical symptoms of a malfunctioning electronic module in this guide, along with helpful advice on how to fix it. If you’re the do-it-yourself type or are thinking about getting professional assistance, being prepared can help the repair process go more smoothly and less stressfully.

Which part is responsible for what?

You might be shocked to see how many semiconductor elements are present in the LG washing machine control module when you first look at it. It will take a long time to check them all, so you must know which sensors are in charge of what. After that, you’ll be able to quickly identify the flaw by comparing this information with the "symptoms" of the breakdown.

The LG washing machine module is typically made up of two components. This is the power unit and control panel. The part will need to be disassembled in order to access the board itself. The washing machine’s various units are controlled by semiconductor elements located beneath the compound and casing.

Certain components of the LG washing machine are operated by each semiconductor element.

Thus, consider what it was about the machine’s operation that you did not like in order to avoid checking every semiconductor. You’ll need to test the sensors that are powering the device if it simply stopped turning on. The HS1 power assembly, which regulates the drive motor, should be closely observed if there were issues with the inverter motor. Let’s examine everything sequentially.

The components that supply power to the machine are located on the left side of the control module. These are the following:

• integrated stabilizer KIA7805, on the board it is designated U14;
• pulse converter based on the PWM controller STR-A6059M;
• network rectifier and filter (designated BD1 and CE4);
• protective varistor (Z2);
• network fuse;
• key converter microcircuit (designated U12);
• SMPS pulse transformer;
• diode D13, capacitor CE2;
• diode D11, capacitor CE8, power supply channel 9V;
• diode D12, capacitor CE9, power supply channel 12V;
• diode D14, capacitor CE6, power supply channel 12V;
• diode D6, zener diode ZD1, transistor Q1, resistor R103;
• resistor R74, aka 205;
• optocoupler U15, transistor assembly U3;
• processor U13;
• relay X1 (it is also connected in series to the heating element circuit);
• integrated voltage stabilizer 5V, designated U

The temperature sensor is the next component on the control board. The following semiconductors are included in this:

• contact 4 (TH1) of the RD6 connector;
• resistor R12;
• 37 leg of the U processor

The heating element’s functionality is provided by the following semiconductors in the module:

• relay X1;
• 64 leg of the U13 processor;
• 1 and 16 legs of the U3 assembly;
• relay X2;
• 24 leg of the U13 processor;
• transistor Q7.

There is a backup relay control channel on the module as well. Installing components is optional. Here are the semiconductors that are under discussion:

• 75 leg of the U13 processor;
• resistor R83;
• transistor Q5;
• relay X4;
• second contact of the BL connector

The pressure switch operates because of the following semiconductors:

• resistors R6, R7;
• 67 leg of processor U13.

The pre-wash compartment valve is controlled by the next block of semiconductors. These are the following:

• 29 leg of processor U13;
• 4 and 13 legs of assembly U3;
• resistor R25, R29;
• optocoupler U8;
• triac TR3;
• contact 1 of connector YL4.

The primary wash compartment valve is operated by the following people:

• Pin 31 of the U13 processor;
• Pin 6 and 11 of the U3 assembly;
• Resistor R23, R27;
• Optocoupler U6;
• Triac TR5;
• Contact 4 of the YL4 connector.

The hot water inlet valve is managed by the circuit listed below:

• Pin 31 of the U13 processor;
• Pin 6 and 11 of the U3 assembly;
• Jumper J1;
• Resistor R24, R28;
• Optocoupler U7;
• Triac TR4;
• Second contact of the YL4 connector.

The washing machine drain pump functions because of the following semiconductors:

• Pin 61 of the U13 processor;
• Resistor R77, R79, R82;
• Transistor Q4, Q3;
• Optocoupler U4;
• Triac TR20;
• contact 4 of connector BL4.

If the washing machine hatch locking mechanism isn’t working properly, take note of the following block of components:

• 27 leg of processor U13;
• 2 and 15 legs of assembly U3;
• resistor R21;
• optocoupler U2;
• relay X3;
• contact 1 of connector BL4.

The Hall sensor, which keeps track of engine speed, is operated by the following people:

• contacts 4 and 6 of connector BL6;
• resistor R44, R60;
• 3,4,5,6 pins of the U1 microcircuit;
• 19,20 pin of the U processor

Check the following circuit if the washing machine’s motor has failed:

• 17 pin of the U13 processor – HS1 power assembly (output stages and drivers) – U1 microcircuit;
• comparator from the U11 microcircuit – RA storage choke – resistor R58, R57;
• 6,7 pins of the U11 comparator – 300V supply voltage control, the signal goes along the circuit with the BD1 diode assembly, resistor R70 and 41 pins of the U processor

The U13 processor’s pin 74, which is the program switch selector, is operated by resistors R73, R72, and 73.

You can see that the board is filled with semiconductor components, so even a novice who knows nothing about microcircuits might find it difficult to repair the control module. You could try fixing the device yourself if you understand the general construction of circuits and are not shocked by concepts like resistors, relays, and optocouplers.

Typical malfunctions

In LG washing machines, a breakdown involving damage to the electronic module is not common. Usually, a unit or sensor is at fault rather than the control unit. For instance, check the socket, power cord, plug, interference suppression filter, and start button before disassembling the board if the machine won’t turn on.

Rarely, though, the control module will actually be the source of the issue. We’ll walk you through how to look for specific washing machine malfunctions on the board.

• The washing machine does not turn on, while the indicator on the electronic module is on. First of all, the power signal circuit is checked, whether it comes after pressing the button to the 63rd leg of the U13 processor (via the U15 optocoupler and terminals 13 and 14 of the U3 assembly). If everything is fine, the 9V power supply channel is tested, they look at whether the specified voltage goes to the X1 relay winding.
• The machine turns on, but during the engine operation, the display shows the LE error. Usually, such a malfunction is caused by damage to the Hall sensors and their circuits. You will need to check and replace the current-limiting SMD resistors on the module. You will first need to remove the compound on the tachometer block.
• The washing machine turns on, but the engine does not work. At the same time, the PF error is displayed on the display. Usually, such a breakdown is associated with the lack of 300 V power supply. on the HS power assembly First, the integrity of the FUSE1 fuse is checked, and then the semiconductors of the BD1 circuit – HS1 assembly – resistor R70 on the 41st leg of the U13 processor.
• If, after turning on the washing machine, the CE error appears, then there is a current overload in one of the output stages of the assembly or a defect has appeared in the control circuit (resistor R58, R57, pins. 6 and 7 of the comparator U11 on the 17th leg of the U13 processor). Then you will need to replace the HS assembly. It is also worth checking the integrity of the engine windings, perhaps the matter is in the interturn closures.
• The machine turns on, but the cycle does not start due to the de error. This means that the hatch door is not locked. The serviceability of the optocoupler U2 and all elements of its circuit (connector BL4, resistor R21, 27 legs of the processor U13) is checked.
• If the washing machine refuses to drain water, while all possible blockages of hoses, sewers and pump failure are excluded, the block of elements is tested: resistors R77, R79, R82, transistor Q4, Q3, optocoupler U4, triac TR

Ensure that the malfunctioning washing machine units are not the source of the issue before testing the control module. Start the control board diagnostic process only after the failure of the remaining components has been ruled out. It is not necessary to inspect every semiconductor; only those that match the "symptoms" of the problem need to be looked at.

Although fixing an LG washing machine’s electronic module might seem difficult, knowing the fundamentals will help the process go much more smoothly. When dealing with irregular behavior, defective cycles, or outright malfunctions, the electronic module is frequently the source of the issue.

Accurate diagnosis of the problem is crucial before beginning repairs. Occasionally, all that may be required is a straightforward reset or software update. If the issue still doesn’t go away, though, you can try testing the connections and looking for any obvious damage on the module.

It may be best to consult a professional for more complex issues. They are capable of handling more intricate fixes and making sure that every part is operating at its best. Recall that keeping your washing machine’s electronic module in good working order guarantees both the machine’s longevity and its effectiveness.

Repairing the electronic module in an LG washing machine can frequently be the best course of action for getting it back up and running smoothly. This post will explore common problems with these electronic modules, troubleshooting techniques, and repair procedures. We’ll walk you through everything you need to know to take on this repair with confidence, whether you’re a do-it-yourself enthusiast or just want to learn more about the procedure.

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