We repair a household hair dryer: how to do it at no extra cost. Schematic diagram of a technical hair dryer

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 it takes several hours for long hair to dry well at room temperature, 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 statistics on the sale of hair dryers as a gift to women on various occasions. It is these devices that occupy one of the leading places, since the thing is necessary and inexpensive.
But no matter how high-quality the product is, elevated temperature, 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 buying a 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 fastest 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. Remove the side of the handle

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: a wire from the power cord - blue, a black wire that goes further to the heater, and one terminal of the capacitor.

The position switch has three outputs. One common, to which a phase brown wire comes from the power cord.
On the other hand, a diode is soldered to the pins.

If you look at the 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 the 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, you should pay attention to their external condition. 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 rest the lower part of the case against 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

Under it is the switch handle, on the reverse side of which a special relief is cut out, thanks to which the contacts are pressed or raised at a certain position of the switch lever.

Rice. 16. The internal arrangement of the 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, thanks 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 the switch to normal operation, 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, we put on it the upper part of the 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.

replacement-provoda

spirali

diagnostics

Brown

Philips

Bosch

The intense use of the hair dryer, as well as possible damage to the device during operation, necessitates periodic repair of the motor and hair comb.

MOSSERVICE offers professional repair services for hair dryers of various brands and models:

mild degree - replacement of nozzles, power cord, cleaning and lubrication of individual parts and assemblies;
medium degree - with complete disassembly of the device (replacement of brushes of the electric motor, switch, diodes, burnt resistances);
complex - replacement of an electric heater, transformers, an electric motor, thermocouples.

Repair of a hair dryer in Moscow is necessary if there is a burning smell, sparks, no heating of the air jet, weak fan rotation, and also if the comb in the hair dryer does not work and there are other problems using the device. Professional specialists are able to competently eliminate any malfunction within a short time. Mosservis workshop does not recommend do-it-yourself repairs of household appliances, trust our professional craftsmen!

Hair dryer repair price list**
№	Name of types of work	Service cost
1	Diagnostics*	600 rub.
2	Cleaning, prevention	from 600 rubles
3	Replacing the thermal fuse	from 1000 rub.
4	Impeller replacement	from 800 rub.
5	Heating element repair (coil/head)	from 1000 rub.
6	Replacing the heating element	from 1200 rub.
7	Switch box repair	from 1000 rub.
8	Replacing the switch block	from 1200 rub.
9	Motor repair	from 800 rub.
10	Motor replacement	from 1000 rub.
11	Electronics repair	from 1000 rub.
12	Electronic module repair	from 1200 rub.
13	Replacing the electronic module	from 1200 rub.

*Diagnostics is included in the cost of repair

*This offer does not constitute a public offer

Why us?

The MOSSERVICE service center offers services for the repair of household appliances at attractive prices in Moscow and the region. Our craftsmen use in their work only original components and spare parts from Italy, the USA and Germany - you can be sure of the quality and reliability of the services provided, as well as our favorable prices.

When deciding to repair a comb in a hair dryer, replace the brushes of an electric motor and eliminate other breakdowns in MOSSERVICE, you get a guaranteed effective result and a prompt visit of the master to your home on any day of the week from 9 am to 10 pm. Over 20 years of work, we have accumulated vast experience in the restoration of various household appliances and have taken a leading position in this field. Order the service online or contact us at the numbers indicated on the site. After the repair of household appliances, our service gives a guarantee for the work performed.

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This electrical appliance - a hair dryer - is very popular and often indispensable in everyday life. Due to high consumer demand, the designs of most hair dryers have become very similar, and the workmanship and price have fallen. To date, it is very difficult to buy a truly durable hair dryer. The practice of repairing hair dryers of various brands suggests that the breakdowns that occur are of the same type and, as a rule, are not fatal, but can be easily fixed without serious cash outlays.

Any electric hair dryer in its design contains two main, large elements: a fan and a heater. The fan drives air through the heater (heating element), sucking it in behind the hair dryer and throwing it out in front heated.

Hair dryer device.
1 - propeller; 2 - electric motor; 3 - heater; 4 - thermal protection; 5 - mode switch; 6 - power cable.

For household hair dryers, the fan is built on the basis of low-voltage (12-18 V) DC collector motors. Such a motor cannot be powered directly from a 220 V AC mains. To achieve the required voltage drop, a separate coil (let's call it a step-down coil) is used inside the heating element. To rectify the voltage, a full-wave rectifier (diode bridge) is used, mounted by surface mounting on the contacts of the electric motor. A plastic propeller consisting of three or more blades is planted on the metal shaft of the engine.

The heating element of the hair dryer is a frame made of fireproof material with several windings of nichrome wire (spirals). Depending on the number of operating modes of the hair dryer, there can be two or three windings, one of which is lowering.

Heating element with two windings.

The hot coils of the heating element must be constantly blown with cold air, especially when operating at maximum power. If for any reason the air supply becomes insufficient or stops altogether (for example, the engine fails), then, for fire safety reasons and in order to avoid the heating element burnout, the hair dryer should automatically turn off. Such an emergency shutdown occurs due to the presence of two temperature-sensitive elements in the device of the hair dryer at once - two “protection lines” inside the heater.

The first "frontier" is the thermostat. It is a pair of closed contacts attached to. Being close to the outlet of heated air, the contacts are intensively blown by it. When the outgoing air reaches a critical temperature, the contacts move away from each other, the power supply circuit of the hair dryer opens. After a few minutes, when the bimetallic plate cools down, the contacts will close again and the hair dryer will turn on.

Thermostats based on bimetallic plates.

If for some reason the above protection did not work at the right time, then a few seconds later the "second frontier" of protection is activated - the thermal fuse. This fuse is a one-time fuse and, once tripped, needs to be replaced.

Thermal fuse.

Device hair dryer Rowenta CV 4030.

To see the internal structure of a household hair dryer, let's analyze its typical representative - Rowenta CV 4030. This model is equipped with a fan based on a low-voltage motor, the heating element consists of one lowering spiral and two heating ones. The hair dryer has three operating modes, in the first mode the fan speed is lower than in the other two. The schematic diagram of this hair dryer is presented below.

In the first switch position SW1 mains power passing through the plug XP1, filter C1R1, protective elements F1, F2, diode VD5(required to cut off one half-wave of alternating voltage) enters the step-down coil H1, through which the electric motor is powered M1. Diodes VD1-VD4 needed to straighten a low helix H1 AC voltage. Inductors L1, L2 and capacitors C2, C3 serve to reduce the interference that occurs during the operation of the brushed motor. Through the diode VD5 power is also supplied to the heating coil H2.

When switching the switch SW2 to position "2", diode VD5 short-circuited and "leaves the game". The engine starts to work at maximum speed, the spiral H2 heats up more. The third position of the switch slider SW2 corresponds to the mode of maximum power consumption, when parallel to the spiral H2 the spiral is connected H3. In this position, the temperature of the outgoing air is the highest. The "cool" button is included in the break of both heating coils, when it is pressed, only the electric motor through the coil remains switched on H1, spirals H2 And H3 are de-energized.

The process of opening the hair dryer Rowenta cv4030.

Hair dryer in a semi-disassembled form.

A hair dryer is an electrical device, which is a piece of pipe through which a stream of air heated to 60 ° C is supplied at a high speed in a given direction. Often, for ease of use, the pipe is equipped with a pistol grip.

The photo shows a 1600W Melissa Magic hair dryer. On the handle there is a switch for operating modes, with which you can turn on the hair dryer and stepwise change the temperature of the air emanating from its nozzle.

A building hair dryer in appearance, principle of operation, device and electrical circuit practically does not differ from a hair dryer. Only in it the air flow is heated up to 600°C.

The device and principle of operation of the hair dryer

When the hair dryer is turned on, the cold air from the room is sucked into its pipe using a rotating impeller mounted on the shaft of a DC motor. Further, the air flow passes through a tetrahedral heat-resistant frame made of mica or ceramic, on which a heated nichrome spiral is wound. Cooling the spiral, the air flow is heated to a temperature of 60°C, and in the building to 600°C, after which it exits the pipe.

On the body of the hair dryer, there is usually a switch combined with a step-by-step setting of the operating mode, which allows you to turn on the hair dryer in full or half power mode.

The photo shows the appearance of a typical sliding mode switch.

To prevent skin burns during hair drying and the destruction of the hair dryer body in case of engine malfunction, a thermal protection in the form of a bimetallic plate is installed on the frame.

When the air is heated above the set temperature, the bimetallic plate bends upwards in the direction of the arrow in the drawing and opens the contacts. The heating coil is de-energized and the air heating stops. After cooling, the bimetallic plate returns to its original position, and the contacts close again.

As you can see, the principle of operation and the device of the hair dryer are not much different from other heating household electrical appliances and any home master can repair the hair dryer.

Hair dryer circuit diagram

Most building hair dryers and hair dryers have the wiring diagram below. The supply voltage is supplied through a C6 plug with a flexible cord. Capacitor C1 serves to suppress interference emitted by the brush assembly of the motor. Resistor R1 is used to discharge the capacitor C1 after disconnecting the plug from the outlet to prevent electric shock to a person when touching the pins of the plug. In some models, elements C1 and R1 are not installed.

The operation of the hair dryer is controlled using switch S1. In its position, shown in the diagram, the hair dryer is in the off state.

When the switch slider is moved one step to the right, its movable contact closes terminals 1-2 and the supply voltage through the rectifier diode VD1 is supplied through the current-limiting coil H1 to the motor and the heating coil H2. The diode cuts off half of the sinusoid and thus reduces the speed of rotation of the impeller and the heating power of the H2 coil by half.

When the engine is moved one more step, contacts 1-2-3 are closed, all mains voltage is applied to the heating element and the engine and the hair dryer operates at full power.

Usually, DC motors are installed in hair dryers, designed for a supply voltage of 9-12 V. To reduce the voltage, an H1 spiral is used. To convert AC to DC, a diode bridge VD2-VD5 is used. The electrolytic capacitor C4 smooths out the ripples. Spark quenching capacitors C2-C3 perform the task of extinguishing sparks in the brush-collector assembly of the engine and suppressing radio interference.

The S2 button is used to switch the operation of the hair dryer to the cold air blowing mode. When you press it, the H2 coil stops heating.

To protect the hair dryer from overheating, which can occur due to a decrease in the speed of the impeller in the event of an engine malfunction, there is a thermal protection element St, which opens the supply voltage circuit to the H2 heater when the maximum allowable air flow temperature is exceeded.

How to repair a hair dryer with your own hands

Attention! When repairing an electric hair dryer, care must be taken. Touching exposed parts of a circuit connected to an electrical outlet may result in electric shock. Don't forget to unplug your hair dryer!

If a broken hair dryer came to you for repair, then first of all you need to find out by what external signs the hair dryer was found to be faulty. According to them, using the table below, you can immediately guess where to look for a malfunction.

External manifestation, causes and troubleshooting hair dryer
External manifestation	Probable Cause	Remedy
Hair dryer turns off intermittently when drying hair	The power cord is frayed at the exit from the hair dryer body or plug	Repair or replace the power cord or plug
The air from the hair dryer comes out hot with a burning smell	Insufficient speed of rotation of the impeller as a result of winding hair on the motor shaft between the impeller and its housing
Hairdryer turns off after a short run	Thermal protection is triggered due to insufficient rotation speed or impeller stop as a result of winding hair on the motor shaft between the impeller and its housing	Remove hair from the shaft with a sharp tool
Hair dryer does not turn on	The power cord is broken or the mode switch is faulty	Repair or replace the power cord or switch
Hair dryer blows cold air	The heating off button is faulty, the coil is broken, the contacts in the thermal protection element are oxidized	Ring parts with a multimeter, repair or replace faulty parts
Hairdryer works only in one of the positions of the mode switch	The mode switch is faulty, one of the spirals is broken or the VD1 diode	Ring the switch, diode and coil with a multimeter, repair or replace faulty parts

How to disassemble a hair dryer

It can be more difficult to disassemble a hair dryer than to repair it, since the parts of the body are usually connected inside using latches, the location of which is not visible from the outside.

But there is always a self-tapping screw on the handle in the area of \u200b\u200bthe entrance to the power cord housing, usually closed with a decorative plug or sealed with a label. Thanks to the different colors of the parts of the body of the Braun hair dryer shown in the photo, you can see which line to disassemble it.

This is what the decorative plastic plug looks like in the hair dryer case. Since it is the same color as the handle, it is difficult to notice. To remove the plug, you need a sharp object, for example, an awl or a knife with a sharp end of the blade, pry it over the edge.

After removing the plug, the head of the self-tapping screw became visible, but it turned out that the slot on it is triangular, while its edges are made in such a way that the self-tapping screw can only be screwed clockwise. The manufacturer provided that at home it was impossible to disassemble the hair dryer for repair without breaking the case.

To unscrew a screw with such a head, it was first heated with the tip of a heated electric soldering iron. To do this, just press the soldering iron tip to the head and hold for a couple of minutes. From the heating of the self-tapping screw, the plastic around the thread softened. Further, while the plastic has not cooled down, using a screwdriver with a flat sting with a width equal to the length of the edge of the triangle of the slot, the self-tapping screw was unscrewed without difficulty.

In order to avoid difficulties in the follow-up repair of the hair dryer during assembly, the self-tapping screw was replaced with the same size, but with a slot in the head for a cross bit.

The removable part of the case was additionally held on by four more latches. Two of them were on the sides of the pipe. For disassembly, it was necessary, simultaneously with the dilution of the parts, to squeeze them out through the gap formed with a flat screwdriver.

After disengaging the side latches, the upper ones released themselves. The latches were shallow, so I was able to disassemble the hair dryer without breaking them.

In this hair dryer, the power cord was faulty, and therefore it was not necessary to disassemble it further, since the place where the cord was connected to the electrical circuit became available.

Hair dryer repair examples

Most often, hair dryers break down due to rubbing of the power cord or malfunction of the electric motor with the impeller. In modern hair dryers, due to the presence of thermal protection and the use of thick wire for winding the spiral, it very rarely burns out. Of the dozens of hair dryers repaired by me, there was no blown spiral.

Hair dryer power cord repair

When drying hair, the hair dryer moves intensively and the power cord is constantly bent. Although the wires in the cord are copper and stranded, they break off over time from repeated kinks. A sign of the beginning of a wire break is the periodic temporary cessation of the hair dryer while drying the hair.

Therefore, half of the breakdowns are associated with chafing of the power cord at the point of exit from the case, less often at the plug. The first sign of such a breakdown is interruptions in the operation of the hair dryer while drying the hair. At this stage, it is easy to find out the location of the cord defect. It is enough to fix it in the middle and move the cord first at the entrance to the plug body, and then at the entrance to the hair dryer body. If the hair dryer works stably at the same time, then the cord is in order and the fault must be sought elsewhere.

If the wires in the cord are frayed at the point of exit from the plug, then you can repair the hair dryer without disassembling it. How to replace the plug is described in the article "Electric plug, how to connect, repair".

Usually, the wires of the cord inside the hair dryer are soldered to the printed circuit board or connected using the terminals, as in the above photo.

To check the cord, you need to ring the wires by touching one of the tester or multimeter probes to one of the pins of the plug. With the second probe of the multimeter, alternately touch the ends of the wires. One of the wires should show zero resistance. There should also be zero resistance between the remaining wire and the second pin of the plug.

If the wires are ringing, then moving the cord at this time, you can determine exactly where the wire is frayed. In the repaired product, the cord was cut off at the point of entry into the hair dryer.

If the wires of the cord are soldered to the printed circuit board, then you can ring them without soldering by attaching the probes of the device to the pins of the plug. The dryer switch must be set to maximum power. The heating coil has a resistance of about 30 ohms. Therefore, if the cord wires are working, then the multimeter should show the same resistance.

Using the online calculator, you can accurately calculate the resistance value of the nichrome hair dryer coil, based on its maximum power.

In the hair dryer being repaired, the cord was broken at the point where it was inserted into the body. To restore work, you need to cut off the defective section of the wire and remount the cap terminals. To remove the terminals from the wires, you first need to use a knife to unbend the antennae to the sides that fix the wires, as shown in the photo.

In the next step, the frayed section of the wire is cut off and the insulation is removed from the cord and wires. The length of the cord will decrease by a dozen centimeters, which will not affect performance.

It remains to tin the wires and terminals with solder with an electric soldering iron and solder them together. After putting on the terminals, assembling and checking the operation of the hair dryer, the repair can be considered complete.

If there is no soldering iron at hand, then in this case the wires are cut off at a distance of 3-5 cm from the place of connection to the electrical circuit of the hair dryer and a segment of the defective cord is removed. Then the wires are connected in one of the mechanical ways, depending on the internal free space in the handle of the hair dryer.

Engine Power Circuit Repair

I got a Melissa-1600 hair dryer to be repaired, complaining that the air flow from it had become weak with a burning smell. When checking, it turned out that the impeller rotated at insufficient speed. I immediately assumed that hair was curled on the motor shaft between the impeller and the housing. Usually, in most cases, with such signs, this happens.

But after disassembling the hair dryer, it turned out that one of the rectifier diodes installed on the motor was torn in half. The continuity of the remaining diodes showed their serviceability. Therefore, the engine worked, but only one half-wave of the rectified voltage was supplied to it.

The faulty diode was soldered and in its place, with the observance of polarity, the first type KD105 that came across was soldered. The motor supply voltage is usually 9-12 V at a current of not more than 0.5 A. Almost any rectifier diode will provide such parameters.

At the same time, winding hair was removed from the motor shaft and the bearings were lubricated with machine oil. To do this, it is enough to apply a drop of oil to the fixation point of the shaft in the motor housing and turn the shaft by the impeller several times.

Before installing the engine in a hair dryer, it is advisable to check it. For the operation of the motor, a constant voltage of 9-12 V is required. But since the voltage is supplied to the diode bridge, the motor can be powered from both a direct and alternating current source. Even the simplest adapter from any device will do, giving out the appropriate voltage and current up to 0.5 A.

You need to apply voltage to the input of the diode bridge, the points of its soldering to the electric circuit of the hair dryer. If the motor is connected to a constant voltage source, then the test must first be carried out with one connection polarity, and then the connected wires should be reversed. This is necessary to test all bridge diodes.

Tests of the engine after preventive maintenance and repair showed that its impeller, when scrolled by hand, rotated easily and when voltage was applied from an external voltage source at a sufficient speed.

Checking the hair dryer after assembly showed that its performance was fully restored. The impeller rotated at high speed, and the smell of burning disappeared.

Repair of the switch and cold air switch button

If the hair dryer cannot be turned on and the power cord is working, then the cause, as a rule, is a broken contact in the mode switch. And if all the modes of the hair dryer, but the air does not heat up, then the heating off button is faulty, the heat protection or the spiral is burned out.

The mode switches in a hair dryer are usually soldered into a small printed circuit board, which is fixed in guides or screwed on with self-tapping screws. The photo shows the switch leads soldered into the PCB. The hot air switch is visible on the left side.

If the mode switch does not ring, then you can try to clean the internal contacts with a thin tool through the hole located next to its engine. It happens that only the contact of one of the operating modes has burned out, and the rest are in working order. In this case, you can sacrifice the rarely used mode of operation of the hair dryer and switch the switching to a working contact.

It happens that due to burnt contacts as a result of heating, the switch housing is deformed and the engine is wedged. In the absence of a replacement switch, you can connect the wires directly, leaving only one operating mode for the hair dryer. In this case, you will have to turn on the hair dryer by connecting its plug to the outlet.

If the button to turn off the warm air flow is faulty, and there is nothing to replace it with, then it is enough to short-circuit its conclusions. In this case, this function will no longer work, but otherwise the hair dryer will work as before.

Thermal protection repair

Thermal protection consists of two contact contacts, one of which is fixed on a bimetallic plate. When the plate is heated above a given temperature, it bends upwards, as the arrow in the photograph shows. As a result, the contacts open, and the power supply circuit of the heating coil is broken.

If the button to turn off the hot air supply is in order and the spiral is intact, then it is obvious that the contacts in the thermal protection relay have oxidized. To restore, it is enough to introduce fine-grained sandpaper folded in half into the gap between the contacts and, pressing the bimetallic plate from above with your finger, stretch the paper several times.

Heating element malfunctions - coils

If the air flow from the hair dryer is cold when the engine is running, the shutdown button and thermal protection are working, then the breakdown is associated with a nichrome spiral.

A broken spiral is easy to detect by external inspection. And the violation of contact in the joints in the form of hollow rivets on the frame of the hair dryer of the ends of the nichrome wire with the wires coming from the mode switch cannot always be determined by appearance. If the rivets do not have blackening, then in this case only a continuity test with a multimeter will help.

To restore contact in the rivet joint, it is necessary to additionally compress it with the help of pliers. The work must be done carefully so as not to break the fragile mica or ceramic frame.

Burnout or breakage of the spiral in modern hair dryers practically does not occur, but if such a failure occurs, then the spiral will need to be replaced with a new one. Splicing helix wire by twisting or crimping into a piece of aluminum or brass tube will not lead to long-term success. If the spiral is worn out, then after such a repair it will soon burn out in another place.

A nichrome spiral, taking into account the power of the hair dryer, can be purchased new or wound independently from nichrome wire, calculating its diameter and length according to the table.

Hair removal and lubrication of the hair dryer motor shaft

Another common hair dryer malfunction that you can fix on your own, having only a standard set of tools at hand, is when the hair dryer is working, but the outgoing air jet is very hot with a burning smell due to winding hair on the motor shaft or poor lubrication of the motor bearings.

Removing hair from the motor shaft of the BaByliss hair dryer

The BaByliss dryer shown in the photo came to me for repair with a complaint that the outgoing air stream had become weak and very hot.

When checking, by the sound of the fan, it became clear that the frequency of its revolutions was underestimated, and the cause of the malfunction lay in the operation of the engine. To fix the problem, the hair dryer had to be disassembled.

In order to disassemble the BaByliss hair dryer, you first need to remove the nozzle by unscrewing two screws. Next, using a screwdriver with a flat sting, the fixing ring is removed, installed on the side of the heated air outlet. It lends itself easily.

It remains to separate the body halves, which are held by two latches on each side. In the photo, due to the translucency of the plastic, the latches are clearly visible, as in the photo in the form of light stripes.

The hair dryer is disassembled and it remains to get to the place of the shaft where the hair is wound. The engine is fixed inside a plastic housing, which is a pipe in such a way that to remove it, you need to remove the fan impeller. And the impeller, as a rule, is tightly mounted on the shaft, and here usually great difficulties arise, since it is impossible to grab the impeller with a standard tool, and it is easy to break it.

To solve such problems, I have made a special tool from Chinese platypuses - a platypus with the ends of the sponges bent at right angles. With the help of a vise, the ends were easily bent, as they were not hardened.

With this platypus, I also successfully repair the runners of snakes and lightning, in case the links stop closing. Ordinary pliers often cannot be reached. And thanks to the curved ends of the jaws, in any case it is easy to squeeze the part of the slider that closes the links.

In addition, the upgraded platypus pliers make it convenient to hold axles and shafts, nuts and other objects of various shapes - they do not slip out, as from pliers with flat jaws.

After removing the impeller from the motor shaft, access to the twisted hair appeared. In this model of a hair dryer, a brass bushing is mounted on the motor shaft, and an impeller is already put on it. Usually it is mounted directly on the motor shaft.

It remains only with a sharp object, such as a knife, awl or needle, to remove the hair and assemble the hair dryer in reverse order. In order to avoid difficulties when assembling the hair dryer, I advise you to take a few photos when disassembling.

Hair removal and lubrication of the motor shaft of the Viconte hair dryer

The Viconte hair dryer had the same outward manifestation of the malfunction as the BaByliss, but in addition the air came out with a burning smell and the fan worked with a rattle. This indicated that the lubrication of the engine bearings had developed.

The sequence and technology of disassembling the hair dryer is similar to that of the BaByliss hair dryer, so there is no need to describe it.

The supply voltage with the help of two wires was applied to the diode bridge soldered at the motor terminals. For ease of repair, the wires were soldered with a soldering iron. You don't have to remember the colors of the wires, since the bridge is supplied with alternating voltage, and the order of connecting the wires does not matter.

An attempt to remove the impeller from the motor shaft with the help of the above-described platypuses was not successful, even with the application of great muscle strength. I had to figure out how to remove the hair and lubricate the bearing without removing the impeller.

The idea came up that you can not suffer with the removal of the impeller, but drill a hole in the engine holder housing, which was done.

The location of the hole to be drilled must be measured so as not to get into the motor housing or the impeller base. First, a hole was drilled with a diameter of three millimeters, and then reamed to five. The body plastic is soft and thin, so the hole can be made with the end of a pointed knife.

A hook was made from a paper clip to remove hair from the motor shaft. To make such a tool, you need to bend the end of the paper clip, sharpen it on sandpaper and bend the very tip to a length of two millimeters. In a minute, all the hairs were removed.

To lubricate the bearing, I had to use a medical syringe. It is enough to apply one drop of oil to the entry point of the shaft into the engine. In order for the oil to get into the bearing, you need to hold the impeller and move the shaft several times along the axis, scrolling it.

Lubricate the bearing on the opposite side of the shaft. Any machine oil is suitable for lubrication, for example, for pouring into a car engine. If there is no oil at hand, then you can remove the oil level dipstick from the engine, from which you can take a few dripping drops.

To test the operation of the fan, a voltage of 10 V was applied to the diode bridge from a DC power supply. The engine will work at a voltage of 5 to 12 V, so even a charger from any phone will do. It is not necessary to do such a check, but if possible, it is better to make sure that the fan has worked as expected.

The check showed the normal operation of the engine, without extraneous noise and sufficient air flow pressure. The hole made can not be closed, as it fits snugly against the body of the hair dryer. If not, then you can stick it with tape.

As you can see, it is not at all difficult to eliminate the most common hair dryer breakdowns, and any home master can do such work if desired. In any case, it is worth trying to repair a failed hair dryer before buying a new hair dryer.