Schematic diagram of a hair dryer. Why does my hair dryer overheat and turn off? What to do with it
As you may have guessed, in this article we will consider the option of repairing an ordinary household hair dryer with our own hands. Since you can always take it to the repair shop, try to make it yourself. For repair and diagnostics, we need a dialer, screwdrivers, pliers and an indicator.
To begin with, we do a visual inspection of the hair dryer, in search of visible mechanical damage. If everything is in order, plug the hair dryer into the outlet and determine the nature of the malfunction. In case of any breakdown, we will still need to disassemble the hair dryer for repair. Let's say the hair dryer does not turn on at all and does not show signs of life, then we have a starting point. First of all, you need to look at the power cord and switch on the handle of the hair dryer.
We look at the body and determine what kind of screwdriver we need, there are many options here, an asterisk, a slingshot, curly, slotted, it all depends on the model of the hair dryer. Having disassembled the case, we carefully study the entire filling of the hair dryer and try to understand what goes where and why it is needed. Putting the dryer disassembled and prepared for repair on a flat dielectric surface, we turn it on.
Next, we take an indicator screwdriver and look where the ends of the power cord go. Checking phase arrival indicator, if everything is normal, then turn the plug in the socket and check the phase on the second wire. If you have established that there is a break in the power cord, then try to find it.
A good way to find a broken cable gently bend and wiggle it so that the places of the cliff are connected and the hair dryer turns on for a short time. Also in the photo are the places where the break occurs most often.
After the power cord, we are looking for a breakdown in the power button according to the same principle. We look where the button has an input and check the presence of a phase, then we look for an output from the button and check it there. Buttons and switches are the main malfunction of household hair dryers, they are not expensive, so do not try to repair them tediously and painstakingly, it is much easier to buy and replace them yourself. Most breakdowns can be determined using visual inspection disassembled hair dryer and indicator screwdriver.
The electric motor of the hair dryer is mainly powered by direct current, which comes from diodes. In order to test the diodes you need a tester. On our electrical website you will find a guide on how to operate the tester and test diodes. It makes no sense to repeat in detail in this article.
We carefully examine the hair dryer spiral and if you find a break in it, then we need to repair it small copper tube . We look at the photo and do the same, do not twist the ends of the spiral together, as they will soon burn out and you will have to repair the hair dryer a second time.
The main breakdowns of the hair dryer
We are all familiar with this auxiliary tool in construction as a construction electric hair dryer, which we used to use to remove paint and varnish coatings.
Fundamental operating principle building hair dryer not much different from an ordinary hair dryer, which we use to dry our hair.
Accordingly and circuit diagram building hair dryer is similar to the electrical circuit of an ordinary hair dryer.
The topic will be explained:
- electrical diagram of a building hair dryer;
- the principle of operation of the building hair dryer;
- possible causes of failure;
- troubleshooting these problems.
Wiring diagram of a building hair dryer
Consider the electrical circuit \Fig.1\ building hair dryer:
One diagonal of the diode bridge is connected to an external source of alternating voltage 220V.
The other diagonal of the diode bridge is connected to the electric motor.
The electrical circuit consists of the following elements:
- toggle switch that implements the temperature control mode - K1;
- toggle switch, which performs the speed of rotation of the rotor of the electric motor \ blowing speed control \ - K2;
- toggle switch for turning off heating elements - K3;
- electric motor\fan\ - M;
- capacitor - C;
- TENOV - R \ TEN \;
- diodes - VD1, VD2.
Through the diode bridge circuit \\ one diagonal of the bridge\, the rectified current of two potentials\+, -\ is supplied to the electric motor. During the transition from the anode to the cathode, the current flows at a positive half-cycle of a sinusoidal voltage.
Two capacitors connected in parallel in the electrical circuit serve as additional smoothing filters.
The blowing speed occurs due to the variability of the resistance in electrical circuit, that is, when switching the speed toggle switch to highest value resistance, - the speed of rotation of the rotor of the electric motor decreases \due to the voltage drop\.
The number of heating elements \ heaters \ in this scheme is four. The temperature regime of the building hair dryer is carried out by a temperature control toggle switch.
The heating elements in the electrical circuit have different resistances - accordingly, the heating temperature when switching from one section of the electrical circuit to another - the heating of the heating elements will correspond to its resistance value.
General appearance building hair dryer with its names of individual parts - shown in Fig. 2
The following electrical circuit of the building hair dryer \ Fig. 3 \, is comparable with the electrical circuit of Fig. 1
There is no diode bridge in this electrical circuit. Blowing speed control and control temperature regime, - occurs when switching from one section of the electrical circuit to another, namely:
- when switching to a section of an electrical circuit - consisting of a diode;
- when switching to a section of an electrical circuit that does not have a diode.
When current flows in the anode-cathode junction of the VD1 diode, which has its own resistance, the heating element2 will heat up according to two resistance values:
- resistance at the transition anode - cathode of the diode VD1;
- resistance of heating element \TEH2\.
When current flows in the anode-cathode junction of the VD2 diode, the voltage supplied to the electric motor and heating element1 will take on the smallest value.
Accordingly, the speed of rotation of the rotor of the electric motor and the heating temperature of the heating element for a given section of the electrical circuit will correspond to the direct transition of the current of the diode VD2. The heating of the heating element \TEN1\ for this section also depends on its internal resistance, that is, the resistance of the heating element is taken into account.
Building hair dryer malfunctions
The main reasons for the failure of a building hair dryer here can be called a malfunction of electronic elements:
- diodes;
- capacitors.
Most often, such a malfunction occurs with a sharp jump external source AC voltage. For example, the cause of a capacitor malfunction is caused by the fact that the capacitor plates are short-circuited during a power surge.
Of course, such a possibility of a malfunction as a break in the stator winding of the electric motor / winding burnout / is not excluded.
Minor faults can include reasons such as:
- oxidation of the contacts of the temperature control toggle switch;
- oxidation of the contacts of the blower speed control toggle switch;
- oxidation of the contacts of the toggle switch for turning off heating elements;
- wire break in the network cable;
- plug failure\lack of contact\.
Diagnostics to identify the cause of the malfunction is carried out by the "Multimeter" device.
When replacing a capacitor, its capacitance and nominal voltage value are taken into account.
When replacing a diode, the resistance of two values \u200b\u200bis taken into account, in the directions:
- from anode to cathode;
- from cathode to anode.
As we know, the resistance value from the anode to the cathode will be much less than from the cathode to the anode.
With an electric motor, if it malfunctions, things are more complicated. With such a malfunction, it is easier to replace the electric motor than let's rewind the stator windings. But even such work is feasible - who is directly involved in such repairs. In this case, the following is taken into account:
- the number of turns in the stator winding;
- section of copper wire.
Such a malfunction as a burnout of the heating element is not excluded. The replacement of the heating element is carried out taking into account its resistance value.
Diagnostics and repair-building hair dryer
Let's consider the device of electric motors and how exactly it is necessary to carry out diagnostics electrical machines, as they are usually considered in the section on electrical engineering.
For good example, photographs of several types of such electrical machines are presented - related to collector electric motors. The device and the principle of operation are allowed for two collector electric motors:
- vacuum cleaner;
- building hair dryer
— is no different. The difference in electric motors is only in the speed of rotation of the rotor and in the power of the electric motor. Therefore, we, as it were, will not focus our attention in the sense that explanations are given that are not related to the electric motor of a building hair dryer.
Electric motor of the building hair dryer
The electric motor of the building hair dryer is asynchronous, collector, single-phase alternating current.
asynchronous collector electric motor of single-phase alternating current
The electrical circuit of the collector motor \Fig.5\ is as follows:
In the circuit, we can notice that the collector motor can operate both from AC and DC - these are the laws of physics.
The two stator windings of the electric motor are connected in series. Two graphite brushes in contact - in electrical connection with the rotor commutator of the electric motor.
The electrical circuit is closed on the rotor windings, respectively, the rotor windings in the electrical circuit are connected in parallel through a sliding brush-collector contact.
diagnostics of motor stator windings
The photograph shows one of the methods for diagnosing the stator windings of an electric motor. In this way, the integrity or breakdown of the insulation of the stator windings is checked. That is, one probe of the device is connected to any of the output ends of the stator windings, the other probe of the device is connected to the stator core.
In the event that the insulation of the stator winding is broken and the wiring of the winding closes to the core, the device will indicate the mode short circuit\zero resistance value\. From this it follows that the stator winding is faulty.
The device in the photograph indicates one when diagnosing - this will not yet mean that this stator winding is serviceable.
It is also necessary to measure the resistance of the windings themselves. Diagnostics is carried out in the same similar way - the probes of the device are connected to the output ends of the wires of the stator windings. With the integrity of the windings, the display of the device will indicate the value of the resistance that one or another winding has. If one or another stator winding breaks, the device will show “one”. If the wires of the stator winding are short-circuited to each other as a result of overheating of the electric motor or for other other reasons, the device will indicate the lowest \ zero \ resistance value or “short circuit mode”.
How to check the rotor winding for resistance with a device? - To do this, you need to connect two probes of the device to two opposite sides of the collector, that is, you need to make the same connection that graphite brushes have in electrical connection with the collector. The diagnostic results are reduced to the same indications as when diagnosing the stator windings.
collector plate wear
What is a collector anyway? - The collector is a hollow cylinder consisting of small copper plates of a special alloy, isolated both from each other and from the rotor shaft.
In the event that the damage to the collector plates is insignificant, the collector plates are cleaned with a fine-grained sandpaper. Again, this amount of work can be performed directly only by specialists involved in the repair of electric motors.
The electrical circuit \Fig.7\ consists of a battery and a light bulb, this circuit is comparable to that of a flashlight. One end of the wire with a negative potential is connected to the stator core, the other end of the wire with a positive potential is connected to one of the output ends of the stator windings. If the wires are connected the other way around, that is, “plus” to the stator core, “minus” to the output end of the stator winding, nothing changes from this.
If there is an insulation breakdown, when the stator winding is closed with the core, the light bulb in this electrical circuit will light up. Accordingly, if the light does not burn, then the stator winding is not closed with the stator core.
This way of diagnosing \Fig.7\ is not complete. Accurate diagnostics is carried out only with an Ohmmeter device or a Multimeter device with a set resistance measurement range, for subsequent measurement of the resistance of the stator windings.
This electrical appliance is very popular and often indispensable in everyday life. When the hair dryer breaks down, you can contact service center, or you can try to fix the hair dryer yourself. The accumulated experience of repair indicates that breakdowns are most often eliminated without serious monetary costs. To repair a hair dryer with your own hands, you need to know how it works and how to properly disassemble it.
How the device works
Any hair dryer has an impeller motor and a heater. The impeller sucks in air from one side of the hair dryer, after which it blows over the heater and comes out already hot on the other side. The hair dryer also has a mode switch and elements to protect the heater from overheating.
1 - impeller; 2 - electric motor; 3 - heater; 4 - thermal protection; 5 - mode switch; 6 - power cable
For household hair dryers, the fan is assembled on a DC collector motor rated for 12, 18, 24 or 36 volts (sometimes there are electric motors operating on an alternating voltage of 220 volts). A separate spiral is used to power the electric motor. DC voltage is obtained from a diode bridge mounted on the motor terminals.
The hair dryer heater is a frame assembled from non-combustible and non-conductive plates, on which is wound nichrome spiral. The spiral consists of several sections, depending on how many operating modes the hair dryer has.
This is how it looks like:
The spiral is wound on a heat-resistant frame
The hot heater must be constantly cooled by the passing air flow. If the coil overheats, it may burn out or cause a fire. Therefore, the hair dryer is designed to automatically turn off when overheated. For this, a thermostat is used. This is a pair of normally closed contacts placed on a bimetallic plate. The thermostat is located on the heater closer to the outlet of the hair dryer and is constantly blown with hot air. If the air temperature exceeds the allowable one, the bimetallic plate opens the contacts and the heating stops. After a few minutes, the thermostat cools down and closes the circuit again.
Thermostat highlighted in red circle
Sometimes as additional protection A thermal fuse is also used. It is disposable and burns out when a certain temperature is exceeded, after which it must be changed.
Thermal fuse, appearance
To better understand how the hair dryer works, you can watch these two videos (watch the first video from the 6th minute):
Video: how the hair dryer works
Video: what's inside the hair dryer
circuit diagram
Scheme of a household hair dryer
The scheme of most household hair dryers is close to the above. Let's consider it in more detail. The heater consists of three spirals: H1, H2 and H3. Through the spiral H1, power is supplied to the engine, the spirals H2, H3 serve only for heating. In this case, the hair dryer has three modes of operation. In the upper position of SW1, the circuit is de-energized. Pregnant<<1>> the hair dryer operates at minimum power: power is supplied through the VD5 diode, which cuts off one half-wave of alternating voltage, only one H2 heating coil is turned on (not at full power), the motor rotates at low speeds. Pregnant<<2>> the hair dryer operates at medium power: the VD5 diode is shorted, both half-waves of alternating voltage enter the circuit, the H2 coil operates at full power, the motor rotates at rated speed. Pregnant<<3>> the hair dryer operates at the maximum possible power, since the H3 coil is connected. When you press a button<
How to disassemble a hair dryer
Attention! Before disassembling, unplug the hair dryer from the socket!
Parts of the hair dryer body are attached to each other with screws (screws) and special latches. Screw heads often have a non-standard shape: asterisk, plus sign, pitchfork. Therefore, you may need the appropriate screwdriver bits. Latches, in turn, are sometimes very difficult to detach and even experienced craftsmen sometimes they just break off. Sometimes the recesses for the mounting screws are covered with stickers, plastic overlays or plastic plugs. Plugs are removed with a sharp object - for example, a knife or a needle. In this case, there is a high probability of slightly wrinkling the body and plugs. True, the hair dryer will not work worse from this. Sometimes the body halves are glued together. In this case, you have to cut them with a knife or scalpel, and glue them together after repair (for example, with epoxy glue).
You can see an example of disassembling a hair dryer in this video:
Video: how to disassemble and repair a Scarlet hair dryer
Typical malfunctions: do-it-yourself repair
Consider the most common hair dryer malfunctions:
Blowing cold air
Possible malfunctions: burned out spiral
What to do:
As a rule, a break is visible to the naked eye, even without a multimeter. There are several ways to repair a spiral:
- You can place the dangling ends of the spiral in a thin brass or copper tube and crimp with pliers.
- The spiral rests on a frame made of heat-resistant, non-conductive plates. In such a plate, carefully make a sharp object round hole about 2-3 mm in diameter, insert a short bolt with a washer there, thread the broken ends of the spiral under the washer and tighten.
- Throw one torn end over the other.
- The broken ends can simply be twisted together. It should be noted that the third and fourth methods are less reliable than the first two. The fact is that when connecting the dangling ends by throwing and twisting, the repaired section of the spiral has an increased resistance and therefore overheats and burns out soon enough in the same place.
- Disassemble the donor hair dryer (of course, if you have one) and take it from there.
- (not for everyone): you can wind the spiral yourself. Where to get nichrome? For example, order in China.
- you can buy a ready-made coil. To find what you're looking for, type in your browser's search bar<<спираль электрическая для бытовых электроприборов купить>>. Spirals are different power and are sold in packs of several.
You can see examples of spiral repair in these videos:
Video: Viconte VC-372 hair dryer repair (coil burnt out)
Video: where you can buy nichrome
Does not turn on, i.e. the fan does not heat up and does not spin
Possible malfunctions: no voltage, that is, a problem with the power cable
How to repair:
First, carefully inspect the cable from the mains plug to the case: for obvious damage. If there is, remove the damaged area and solder the ends of the cable. Perhaps these are all malfunctions and the hair dryer will work. An example of cable repair is in the above video: How to disassemble and repair the Scarlet hair dryer.
Impeller does not turn or turns at low speed
Possible malfunctions: the motor is faulty or hair is wound around its shaft.
If hair is wrapped around the motor shaft, you will have to dismantle the impeller to remove it. You will also need to remove the impeller if you are going to lubricate the motor shaft or replace it. How to do this, you can see in these two videos:
Video: remove the impeller from the hair dryer
Video: how to remove the fan from the hair dryer motor
Also, in some cases, you can grab the base of the impeller with your fingers and pull it off.
With regard to checking the electric motor, the author believes that the best way- from a safety point of view - is to dismantle the motor and connect it to a suitable power supply with short circuit protection. If the motor does not rotate, you need to check the integrity of the windings with a multimeter. If the winding breaks, you will have to buy a new motor (although you can rewind the old one, but this, perhaps, only makes sense as an entertainment). If the engine sparks a lot, you will also have to buy a new one. Wiping with alcohol in this case, if it helps, then not for long. One of the options where you can purchase a new engine: order in China (look for<
Hair dryers with air ionization function and infrared devices
Hair dryers with ionization- when this mode is turned on, a lot of negative ions are released, neutralizing the positive charge on the hair, which makes them smooth and does not dry out. To create negative ions, a special module is used, placed in the handle of the hair dryer. The wire coming out of this module is located in the heater area. The air is ionized when it comes into contact with this conductor.
It is possible to diagnose the health of the ionization module without special devices by indirect signs. If you no longer feel the difference when the ionization module is turned on and off - and you are convinced that the module is receiving normal voltage power - therefore, the module is faulty. Next, you need to find a module for the desired voltage and suitable in size. Look, again, in China.
Photo gallery: an approximate view of the ionization modules
infrared hair dryers dry hair not with hot air, but with infrared radiation. They are quite expensive, belong to the professional category and dry hair much faster than conventional hair dryers. Instead of a nichrome coil, they use an infrared heating element (as in infrared heaters). Otherwise, their design is similar to the design of a conventional hair dryer.
Video: h2d infrared hair dryer
To disassemble and repair a hair dryer, you do not need to be a certified specialist. Enough knowledge of the course of physics high school and the presence of straight arms growing from right place. Keep it up and you will succeed!
Repair of any hair dryer begins, with its complete or partial disassembly, but before we start this process, let's find the answer to the above question.
Absolutely any hair dryer can be divided into two main elements - a heating element and an electric motor. heating element a nichrome spiral is usually used, it is she who heats the air. And DC motors create a warm directional air flow.
Electric motors in hair dryers are 12, 24 and 36 Volt, but sometimes in very cheap Chinese models there are 220 Volt electric motors. A propeller is attached to the rotor of the engine, which provides retraction warm air from the spiral. The power of the hair dryer varies from the thickness of the spiral and the power of the electric motor.
Consider the design of the hair dryer in more detail:
1 - nozzle-diffuser, 2 - body, 3 - air duct, 4 - handle, 5 - anti-twist cord, 6 - "Cold air" mode button, 7 - air flow temperature switch, 8 - air flow speed switch, 9 - "Turbo" mode button - maximum air flow, 10 - loop for hanging the hair dryer.
The body of the hair dryer consists of two plastic halves, a front and rear ring and a mesh. The grid hemisphere is dismantled by a slight counterclockwise turn. The hardest part is pulling out the rear ring where the mains wire enters the base. This ring has lugs with holes and latches. The front ring is removed, although a little easier, but also has two latches on the body halves and recesses in the ring (in the photo below, only one protrusion is clearly visible and the ring is worn before it).
the main elements of the hair dryer and the diagram in the photos below:
Hair dryer Rowenta cv8525 works, but does not heat the air |
Dryer Rowenta repair and disassembly: First, the front metal ring is removed, then the back mesh hides two self-tapping screws under it, unscrew them and remove the back cover from the handle (on latches). Under the overlay are five self-tapping screws unscrew them.
Inspection revealed a classic violation of contact in the button that turns off the air heating. The contact moved a little and stopped closing the coil heating circuit. The repair came down to correct installation contact position and fusing the top of the plastic stand with a conventional soldering iron
Remington hair dryer disassembly and repair |
Job instability. Hair dryer switched off intermittently. First you need to pull out the plugs on the hair dryer handle. You can remove the plugs with a sewing needle or sharp end thin knife.
Under the plugs are screws for a special U-shaped screwdriver. After disassembling the handle, we see - the warm air supply switch (blue), the hair dryer power switch (red). Here it is necessary to inspect everything very carefully in case of a quite probable break in the conductors or melting on the switches.
It is difficult to find a girl or woman who would not use a hair dryer to dry her hair, especially in the cold season. And this is understandable, since long hair dry well at room temperature, you need a few hours, and with the current pace of life - this is a luxury.
Therefore, these devices were, are and will always be in demand. And this is proved by the statistics on the sale of hair dryers as a gift to women on different occasions. It is these devices that occupy one of the leading places, since the thing is necessary and inexpensive.
But no matter how good the product is, fever, high current consumption, and, as a rule, improper operation, often lead to breakdowns of household hair dryers.
Rice. 1. Repairable hair dryer “Startex”
And before you buy new device, you can try to bring an old friend back to life. Moreover, the damage can be minor and easily fixed.
Below, one of the most common breakdowns of hair dryers and how to fix it will be described in detail (using the “Startex” hair dryer as an example).
Of the tools you will need only those that are in almost every home. The only thing that may not be is a multimeter or some other device that shows the circuit. But for sure, a friend or neighbor has it, and you can ask for it for the time of repair. If, nevertheless, there is no good neighbor or electrician friend nearby, you can buy the cheapest multimeter, especially since there are enough of them on the market now. In the future, it will definitely come in handy, for example, to check a light bulb, battery or mains voltage.
In the photo (Figure 1) there is a hair dryer that has a problem in operation.
It lies in the fact that when turned on at maximum power, it does not react in any way.
Fig.2. We looked inside The hair dryer itself has three switch positions:
- The bottom one is "OFF".
- The average is half the heating power.
- Top - maximum heating power.
Rice. 3. Three positions of the hair dryer Most often, a hair dryer is used in the upper position, as it gives the maximum quick drying. Therefore, it is unacceptable to ignore such a breakdown.
So, to find the cause of the malfunction, it is necessary to disassemble the device. Start with a pen.
Rice. 4. Unscrew the handle of the hair dryer It has a position switch and two mounting screws for a Phillips screwdriver.
Put the hair dryer on its side, and unscrew these two screws.
Rice. 5. Shoot side part pens After removing the lid, you can see its filling.
Rice. 6. Hair dryer electronics Here are located: a switch, a diode, a capacitor, a zero (common) clamp and a clamp for fixing the cord.
Rice. 7. Common clamp The zero clamp is located inside the dielectric cap (Figure 7).
It connects: wire from the power cord - of blue color, a black wire that goes further to the heater, and one capacitor lead.
The position switch has three outputs. One common, to which the phase comes brown wire from the power cord.
On the other hand, a diode is soldered to the pins.
If you look at circuit diagram(Figure 8), you can see that in one of the switch positions, the current flows to the heater through the diode. This reduces the heating power and corresponds to the middle position of the switch.
When the second, or both, contacts are closed, the current passes to the heater coil, bypassing the diode, which corresponds to maximum power- the third position.
The capacitor serves to dampen the noise generated by the motor in the network. This capacitor can be completely dismantled. Then there will be more space in the handle, and it will not explode when the voltage in the network rises.
When inspecting these components, pay attention to their external state. There should be no damage, soot, breakage of conductors and deformation of the case from the temperature regime.
If all the wires are in place, you need to pay attention to the switch. This is a weak link in the chain, since the mechanical movement of the contacts occurs in it, and when they open, an electric arc forms carbon deposits on their surface.
You can check the integrity of the diode, but in this case there is no need to do this, since at half power, the hair dryer works, which means the diode is intact.
Rice. 9. Checking the external state of the components You need to check the passage of current through the switch.
To do this, we connect one end of the circuit tester to a common terminal, and the other to the terminals on the opposite side.
But you need to do this at a certain position of the switch.
First, we connect the device where only the diode is soldered, and put the switch lever in the middle position.
Rice. 10. Switch in the lowest position 
Rice. 11. Checking the current through the switch The indicator shows the circuit. This means that the contacts inside the case are closed and this is good.
The switch must be placed in the highest position (Figure 12).
Rice. 12. Switch in the highest position 
Rice. 13. Checking the second output The device does not show the circuit, which means that something has happened to the contacts. Fortunately, the switch turned out to be collapsible. Its upper and lower parts are fastened with two screws.
They must be carefully unscrewed. A screwdriver will help here, and not necessarily a Phillips one. An ordinary straight line, with a small tip, for example, an hour, will do.
The screws are quite tight, so some effort will be required. You need to be extremely careful, the screwdriver is thin and can cause deep injury if it slips off. Therefore, it is better not to put your fingers under the switch.
For convenience, you can remove the entire filling by unscrewing the cable clamp.
Now you can push lower part case on the table and press the screw with a screwdriver (Figure 14).
Rice. 14. Disassemble the switch In this way, small screws are quite easily unscrewed. When both screws are removed, carefully remove the top cover of the switch with two fingers.
Rice. 15. Remove the switch cover Underneath is the switch knob. reverse side which a special relief is cut out, thanks to it, the contacts are pressed or raised at a certain position of the switch lever.
Rice. sixteen. Internal organization hair dryer switch A hole is made in the center of the handle for a spring, which, together with a metal ball (Figure 16), provides stepwise switching of modes. When disassembling, make sure that the spring and ball are not lost. It is better to put them immediately, for example, in a matchbox.
The fixed ones are at the top, and the movable ones have a springy structure, due to which, the contacts close if nothing affects them. When switching modes, the "cams" of the lever press on these contacts, and under their influence, they go down and open.
Rice. 17. Hair dryer switch contacts If you look at the contacts from the side (Figure 18), you can see that the nearest one did not return to its original position to close the circuit.
Rice. 18. We look at the contacts on the side It is this contact that is responsible for turning on the maximum heating power, which did not work.
Below in the photo, you can see how the contacts work. When you press the far contact, it flexes.
Rice. 19. This is how contacts work If you let it go, it comes back and closes the circuit.
Rice. 20. Contact returned back We do the same with the other contact.
Rice. 21. Click on another contact Down, it is pressed, but does not return back (Figure 22).
Rice. 22. Contact didn't come back Most likely, a flexible conductor with a contact rubs against the side inner wall of the switch housing and is blocked in the lower position. This is the reason for the incorrect operation of the device in one of the modes.
To return normal work switch, you must perform the following sequence of actions:
- Gently squeeze the contact block with "ducks" or small pliers. This will give the contact a freer ride in the groove of the switch housing.
Rice. 23. Compress the block of contacts - Additionally, you need to process the edges of the flexible conductors with a needle file. To do this, the contact pad itself can be removed. This will make it easier to process them.
Rice. 24. We clean the edges of the conductors with a file - Also, with a needle file - we clean the contacts from soot.
Rice. 25. Get rid of soot - We put the contact pad in place.
Rice. 26. We put the site in place - For better sliding, we lubricate the inner walls of the body with lithol.
Rice. 27. Litol on the tip of the incisor 
Rice. 28. Lubricate with lithol
Now you can check how the contact progress has improved. Press your finger on the contact, and release it.
Rice. 29. Checking contacts It can be seen that the contact is now working normally, and nothing interferes with its course.
Rice. 30. Spring A metal ball, it is better to insert into one of the grooves on the body (Figure 31). So it will not come off the spring when you install the switch knob.
The important thing is which side to put the switch handle, since the correct operation of it depends on it.
Rice. 31. Assembling the switch When the correct side is determined, we turn the lever so that the center of the spring hits the ball, and not to the side.
Rice. 32. We fall on the ball with a spring Holding the handle, put on it upper part switch housing.
Without releasing the cover, we tighten the two fastening screws (Fig. 33). Now the switch is ready, and without assembling the hair dryer, you can check its operation in different modes.
Rice. 33. We twist 2 screws back Since the current-carrying parts are open, switching modes must be done with the power plug disconnected from the mains. And only after making the switch, apply power.