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All modern washing machines are equipped with a control module. The more functionality the SM has, the more delicate the electronics: it is more prone to breakdowns, since it is sensitive to power surges in the network. Is it possible to repair the “brains” of washing machines with our own hands, how to diagnose their breakdown, we will find out in this article.
The device and principle of operation of the control board
The main control unit of the washing machine is equipped with two boards. One of them is responsible for the operation of all the details of the washing machine. The other provides the operation of the control panel – buttons, indicators – and has the appropriate connectors for wiring.
Is the board not protected from overloads in any way? Of course, the manufacturer has provided for such cases a surge protector that takes the hit during a power surge in the network.
How to check the washing machine board and determine the breakdown?
Causes and symptoms of a malfunction of the control board
The fact is that most of the signs may indicate a breakdown of both the module and other parts. For example, you notice that the machine has stopped working, washing does not start. The reason for this may be a problem with the module or the washing machine motor.
What may indicate a malfunction and subsequent repair of the board in the washing machine:
- CMA issue an error code on the display.
- The system “hangs”, does not respond to user manipulations.
- Washes too long. The machine then gains, then drains the water, after which the system “freezes”.
- The drum abruptly changes direction for no apparent reason.
- Spin mode does not turn on.
- The water overheats or does not heat up, which does not correspond to the selected mode.
However, the next time you start the washing machine, it can work again in the usual mode.
Some CMA models have an autotest that allows you to determine the cause of the breakdown. How to start it is written in the operating instructions for the machine.
Why does the board fail
- A short circuit as a result of a voltage drop can lead to burnout of capacitors, thyristors, triggers and other elements on the board.
- Increased humidity. If the CM is used in a bathroom, over time, the humidity will attack the main unit, causing it to malfunction.
- Power wire broken. If the wire is cut abruptly, a power surge may occur, which will affect the operation of the module.
- Frequent abrupt shutdown of the machine from the network over time can lead to a problem.
- Rarely found a factory marriage.
Be careful when transporting the CM from place to place. Be sure to pull out the powder dispenser as some water remains in it. During transportation, water gets on the main unit, which causes it to burn when connected.
To start the repair, you will need a diagram of the control board of the washing machine, as shown in the example of the Indesit washing machine.
Checking the washing machine control module
We can advise you to superficially inspect the module for burns and damage. There are other ways to check, but only an experienced specialist can conduct them. In case of malfunctions, you will have to replace the “brains” for the washing machine.
To conduct a visual inspection, let’s figure out how to remove the washing machine board. First, unplug the washer from the mains, then do this:
- Pull out the detergent drawer. To do this, pull it towards you while pressing the latch in the center.
- Now unscrew all the screws holding the control panel.
- Use a screwdriver to pry out the plastic latches. Remove the panel from the case.
- Behind the panel is the main unit. Take a photo or mark the location of the wires with a marker. Then disconnect them and remove the block.
- You may need to open the block latches to get to the board.
Once the board is in front of you, inspect it carefully. Noticed burnt areas? Then you need to repair the control unit of the washing machine.
Replacing elements on the control board
We will show you how to replace some elements. To do this, you will need a soldering iron and a new part.
- Capacitor. On the control board, it serves as a kind of stabilizer. To replace it, you need to solder a new part to the positive electrode. To find out where which electrode is, use a tester.
- Resistor. To check the operation of the resistor, a tester is used. The 1st order resistors should show a result of 8 ohms and an overload of 2A. Second order resistors show 3-5A, while the resistance indicators depend on the frequency of the module. If the indicators do not correspond to the norm, the elements are replaced – by soldering.
- thyristor block. You can check the thyristor unit by measuring the negative resistance. Indicators should be no higher than 20V. The block filter could also burn out. You can repair it by cleaning the cathode.
- Trigger. The trigger check consists in measuring the voltage of the input contacts. Their readings should not exceed 12 V. The trigger filter resistance should be 20 ohms. The replacement of the element is also carried out by soldering.
The soldering of the board components may be broken due to strong vibrations of the machine. Therefore, you need to monitor the correct and stable installation of the washer.
The master knows how to properly repair the control board. Think before you start self-repair, because the electronic unit is quite expensive. If you do not have the skills to work with a soldering iron, and the verification indicators do not give specific results, contact the service center.
For those who still decided on an independent repair, a video on the topic: