The multicooker does not turn on: reasons and what to do?

If mul­ti­cook­er not turn­ing on this arti­cle may 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 mul­ti­cook­ers, you should know that all home mul­ti­cook­er pro­grams are trade secrets of man­u­fac­tur­ers. Mul­ti­cook­ers are based on the instal­la­tion of two sen­sors, thanks to which they under­stand what is required of them. Many crafts­men sug­gest­ed that the board con­tained a mem­o­ry of the tem­per­a­ture and dura­tion of indi­vid­ual oper­a­tions and spec­i­fied pro­grams. Thanks to these data, the heat­ing ele­ment (heat­ing ele­ment) is being pro­grammed. Sen­sors installed in the mul­ti­cook­er:

1. Ther­mis­tor. It is installed on the main but­ton of the device. Its dis­man­tling is a rather painstak­ing task, for the rea­son that man­u­fac­tur­ers cat­e­gor­i­cal­ly oppose repairs by self-taught and work­shops, leav­ing it only to war­ran­ty ser­vices. Com­pa­ny Red­mond went even fur­ther, they filled all the ter­mi­nals with a com­pound, mak­ing it impos­si­ble to dis­man­tle the remov­able ter­mi­nals.
2. 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 on 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 be 100% sure of this, it is nec­es­sary to mea­sure the resis­tance of the sen­sor com­ing from the wires and the cov­er using a mul­ti­me­ter. In Red­mond devices, cables are locat­ed in the loop area under a remov­able cov­er. In order to take mea­sure­ments, you need to unscrew the screw, then care­ful­ly remove the shield and remove the wiring from it, then turn on the mul­ti­cook­er while mea­sur­ing the resis­tance.

As fol­lows from the above, for prop­er oper­a­tion, the mul­ti­cook­er needs to take read­ings from two sen­sors. They trans­mit their sig­nal to the con­trol ter­mi­nal of the board via two wires. As a rule, the board itself is installed under the but­ton pan­el. The next pos­si­ble prob­lem could be the pow­er sup­ply. In order to make sure that it is work­ing prop­er­ly, you need to con­nect the mul­ti­cook­er to the mains, if at least one of the indi­ca­tors 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 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 relat­ed para­me­ters for per­form­ing oper­a­tions. All this func­tions thanks to just one wiring. The begin­ning of the process of pro­gram exe­cu­tion 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 is need­ed to turn the tran­sis­tor on or off. Thanks to the volt­age sta­bi­liz­er, over­sat­u­ra­tion can­not occur on the con­tact fields.

Switching power supply

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

If Mul­ti­cook­er won’t 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 in the dis­as­sem­bled state. The resis­tance between the plug and the input ter­mi­nals must be low. The trans­former is fol­lowed by a two-peri­od rec­ti­fi­er of four diodes. After it, an addi­tion­al fil­ter is pro­vid­ed in the pow­er sup­ply from the largest resis­tor with a capac­i­tor. 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 design is respon­si­ble for sup­ply­ing 220V cur­rent to the device, 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 the loss of per­for­mance of the heat­ing ele­ment of the mul­ti­cook­er. But do not imme­di­ate­ly take on the restora­tion of the jumper.

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

To check the oper­a­tion of the relay, you must con­nect the device to the mains and turn on any of the pre-installed 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 grad­u­al­ly replace the relay and con­trol cir­cuit. 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 like to fill every­thing with a com­pound, so be care­ful.

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Consider cases of thermal fuse failure

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 oper­at­ing 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 burn 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, it is not worth deny­ing that these prod­ucts are easy to man­u­fac­ture, but it fol­lows from this that the price for them will be quite low. Sec­ond­ly, it is desir­able to install exact­ly the orig­i­nal ele­ments. A fac­to­ry copy has cer­tain fixed char­ac­ter­is­tics, cal­cu­lat­ed in pro­duc­tion from the very begin­ning, and a copy made by one­self may have dif­fer­ent char­ac­ter­is­tics from it, which can lead to bad con­se­quences. In the worst case, using a home­made part can end up in a fire for you.

Thermal fuse replacement process

Get­ting 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, the “leg” of which is attract­ed by a spring. Under it are ther­mal fus­es, usu­al­ly they are installed in sev­er­al pieces and cov­ered with cam­bric.

Cam­bric is a plas­tic con­duc­tive insu­la­tion ele­ment, in most cas­es white, used to pro­tect the junc­tions of var­i­ous com­po­nents and areas.

In order to attach the ele­ment, it is nec­es­sary to per­form fir­ing. The use of a sol­der­ing iron for these pur­pos­es is strict­ly pro­hib­it­ed. The heat­ing ele­ment of the sol­der­ing iron 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 little about Redmond

Mul­ti­cook­er Red­mond It also has ther­mal fus­es that pro­tect the device from over­heat­ing. These parts do an excel­lent job with 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 ther­mal and oth­er dam­age caused by improp­er oper­a­tion of the device is not a war­ran­ty case.” Since it is not uncom­mon for own­ers to turn on devices with­out a saucepan, this is 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, by neg­li­gence or for­get­ful­ness, you did not set the saucepan in place and poured the ingre­di­ents into it, poured the required amount of liq­uid and for­got to unplug the device, and then remove all mois­ture and food with paper tow­els, but the device stopped work­ing, accord­ing to the man­u­fac­tur­ers, the fault will be lie on you. This is jus­ti­fied by the fact that the guar­an­tee does not apply to get­ting these things into the cav­i­ty of the device, and you will have to pay for expen­sive repairs out of your own pock­et.

Device chips

In typ­i­cal mod­els, two elec­tron­ic boards are installed:

1. Con­trol fee.
2. Pow­er board.

The sec­ond is locat­ed on the bot­tom of the device, but to get to the loca­tion of the first item, you will have to suf­fer a lit­tle and com­plete­ly dis­as­sem­ble the device, while dis­man­tling the inner cylin­dri­cal sur­face.

After you have tak­en every­thing apart, you need to exam­ine the boards for the pres­ence of:

• 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 clean­ing them by tin­ning dam­age and zero sand­ing. You may need to add some jumpers, which you can make from the legs of the resis­tors. After per­form­ing all oper­a­tions, it is nec­es­sary to cov­er every­thing with var­nish to ensure the pro­tec­tion of the device from leak­age and expo­sure to oxy­gen.

Conclusion

If you have Mul­ti­cook­er won’t turn on do not imme­di­ate­ly head­long to car­ry it to the ser­vice. All break­downs are most often due to improp­er oper­a­tion of the device. In the case when you prop­er­ly oper­ate the device, it can work for many years and make your life eas­i­er. In order to fix all the prob­lems, you must fol­low the above instruc­tions and with 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.

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