What to do if the multicooker does not turn on?

Content:

The device and principle of operation of the multicooker
Switching power supply
Consider the cases of a breakdown of a thermal fuse
Thermal Fuse Replacement Process
A little about Redmond
Device microcircuits
Output

If the multicooker does not turn on, this article can help you. We will tell you about how to repair a multicooker with your own hands and reduce the cost of this process.

The device and principle of operation of the multicooker

Before talking about how to troubleshoot multicooker, you should know that all home multicooker programs are the subject of trade secrets of manufacturers. Multicooker is based on the installation of two sensors, thanks to which they understand what is required of them. Many masters suggested that the memory of the temperature and duration of individual operations and preset programs is embedded inside the board. Thanks to this data, the heating element (heating element) is being programmed. Sensors installed in the multicooker:

Thermistor. It is installed on the main button of the device. Dismantling it is a rather painstaking task, for the reason that manufacturing firms are categorically opposed to repairs by self-taught and workshops, providing only warranty services. Company Redmond went even further, they filled all the terminals with a compound, making it impossible to dismantle the removable terminals.
The second sensor is installed inside the cover. To gain access to it, you need to make a lot of effort, so we do not recommend that you take it up if you are not confident in your abilities. It is necessary to remove the required connector without paying attention to the compound, and then start the multicooker. If after turning on the multicooker does not work, then you have found the cause of the breakdown. In order to make sure of this 100%, it is necessary to measure the resistance coming from the sensor wires and the cover using a multimeter. In Redmond devices, the cables are located in the loop area under the removable cover. In order to take measurements, you need to unscrew the screw, then carefully remove the shield and remove the wiring from it, and then turn on the multicooker while measuring the resistance.

As follows from the above, for correct operation, the multicooker needs to take readings from two sensors. They transmit their signal to the control terminal of the board via two wires. Typically, the board itself is installed under the button bar. The next possible problem is the power supply. In order to make sure that it is working properly, it is necessary to connect the multicooker to the mains, if at least one of the indicator lights up, it follows that everything is in order with your power supply.Otherwise, it must be replaced.

Multicooker control is divided into mechanical and touch. If a mechanical control is installed in the multicooker, then microswitches are built into the printed circuit board. By counting the number of "closures", the microcircuit selects the accompanying parameters for performing operations. It all functions with just one wiring. The beginning of the program execution process is carried out by means of transmission of only one signal. However, for this it is necessary to use a large number of functioning control boards installed in the multicooker. The signal is constant and required to turn the transistor on or off. Thanks to the voltage regulator, oversaturation cannot occur on the contact fields.

See also - DIY multicooker repair

Switching power supply

Let's talk in detail about how exactly it works. Its design includes a transformer, pre-wrapped with electrical tape, so that the contact does not fall off, it is occasionally poured with a compound. In order to protect the transformer from input pulsations, an input filter is provided in the design. The multicooker itself does not create ripples. The transformer provides for the installation of two parallel windings. The use of two windings increases the reliability of the device.

If the multicooker does not turn on, it is necessary to measure the resistance of the transformer, it is not necessary to disassemble the device, since the relay is open when disassembled. The resistance between the plug and the input terminals must be low. The transformer is followed by a two-cycle rectifier of four diodes. After it, an additional filter from the largest resistor with a capacitor is provided in the power supply. Next, an emitter follower with a stabilizer and a resistor is installed, which is designed to select the operating point.

Be sure to pay attention to the small gap of the double wire, which is located in the area of the fuse. This part of the structure is responsible for supplying 220V current to the device by connecting to the relay. The main board is installed in the device with the elements down, if the current exceeds the limit value, the copper wire will simply melt and drain to the bottom of the unit, which is completely unprotected from this. If, when removing the main board, you notice this kurtosis, then this means that a short circuit has occurred somewhere inside the device. These damages may indicate a loss of performance of the multicooker heating element. But do not immediately take on the restoration of the jumper.

When measuring the resistance of the heating element, its operating value fluctuates around 30 ohms.

To test the functionality of the relay, you need to connect the device to the mains and turn on any of the preinstalled programs on the multicooker. If a click occurs while the device is turned on, then this is a signal that everything is in order, otherwise it is necessary to replace the relay and control circuit in stages. In order to diagnose a malfunction of the latter, it is necessary to apply voltage to the middle terminal (transistor) along the white wire. Then measure the output voltage. However, it is worth noting that manufacturers love to fill everything with compound, so be careful.

See also:

Consider the cases of a breakdown of a thermal fuse

What is a thermal fuse? This is a small cylindrical piece of wire, which in its external shape may remind you of a resistor.The response temperature of the device is 170 ° Celsius, and the current ranges from 10 to 15 amperes, depending on the installed element. If one of the parameters exceeds the norm, the thermal fuse will blow out, which breaks the electrical circuit and stops the operation of the device.

You could set out to make such a fuse yourself. First of all, one should not deny that these products are easy to manufacture, but it follows from this that their price will be quite low. Secondly, it is desirable to install the original elements. A factory copy has certain fixed characteristics that were calculated at the factory initially, and a copy made with one's own hand may have different characteristics from it, which can lead to bad consequences. In the worst case, the use of a homemade part may result in a fire for you.

Thermal fuse replacement process

To get to the location of this part is not too difficult, first you need to remove the saucepan from the cavity of the device. Under it, you will find a metal element similar to a mushroom, whose “leg” is pulled by a spring. Under it are thermal fuses, usually they are installed several pieces and cover them with cambric.

Cambric is a plastic wire insulation element, in most cases white, which serves to protect the joints of various components and sections.

In order to attach an element, it is necessary to perform firing. Using a soldering iron for these purposes is strictly prohibited. The soldering iron heating element will burn through the heat-sensitive element without much effort and difficulty.

To determine the integrity and performance of one or more elements, you must use a multimeter. It is not necessary to remove the part; after detecting a malfunction, eliminate it according to the above example.

A bit about Redmond

Slow cooker Redmond also has thermal fuses, which serve as protection of the device from overheating. These details do an excellent job of the function assigned to them, but there is one very significant BUT - they are able to do this only once. After that, you will have to seek the help of a specialist in a service center. Here is an extract from the Redmond warranty card: “a product with the presence of thermal and other damages arising from improper use of the device is not a warranty case.” Since it is not uncommon for owners to turn on devices without a saucepan, it’s quite important to know. However, a button is installed in the device, which in theory should prevent the device from turning on without it, but it simply does not work at Redmond.

If you, through negligence or forgetfulness, did not put the saucepan back in place and pour the ingredients into it, pour the necessary amount of liquid and forget to disconnect the device from the network, and then use paper towels to remove all moisture and food, but the device stopped working, according to the producers, the wine will lie on you. This is justified by the fact that getting into the cavity of the device of these things is not covered by the guarantee, and you will have to pay for expensive repairs from your pocket.

Device microcircuits

In typical models, two electronic boards are installed:

Control board.
Power board.

The second is located on the bottom of the device, but in order to get to the location of the first point, you will have to torment a bit and completely disassemble the device, while dismantling the inner cylindrical surface.

After you have disassembled everything, you need to examine the boards for availability:

chips;
blackened resistors;
violation of solder seams;
swollen capacitors;
and soot.

In case of detection of such defects, it is necessary to replace the elements with new ones. Restoring broken soldering should not cause you much difficulty. It is necessary to carry out the process of restoring the tracks by stripping them by tinning damage and zeroing the skin. You may need to add a few jumpers that you can make from resistor legs. After performing all operations, it is necessary to coat everything with varnish, to ensure that the device is protected against leakage and oxygen exposure.

See also - How to use a slow cooker

Output

If you the multicooker does not turn on Do not immediately headlong to carry it to the service. All failures are most often caused by improper operation of the device. In the case when you operate the device correctly, it can work for many years and simplify your life. In order to eliminate all the malfunctions, you must adhere to the above instructions and having common sense, you can easily fix the multicooker. However, remember that if your device is under warranty, it is best to contact a service center.