Cordless screwdriver DIY repair

In detail: do-it-yourself cordless screwdriver repair from a real master for the site my.housecope.com.

The screwdriver is a mobile tool that makes it easier to work with fasteners and screw connections. Until recently, cordless screwdrivers could only be found in the arsenal of professionals, but with the advent of inexpensive household models on the wide sale, their popularity has increased dramatically.

Unlike an expensive professional tool, budget counterparts have a smaller resource, which is why they often fail.

One of the weakest points of a household screwdriver is the start button and reverse switch. As practice shows, it is they that break most often.

As a rule, it all starts with the fact that the soft start function stops working, then a stronger pull on the "trigger" is required to start the electric motor.

Over time, the tool ceases to respond to any manipulation altogether. Often there is a problem of the opposite nature, when the motor starts to work spontaneously.

In some cases, to eliminate the defect, it is enough to disassemble the tool and clean it, although more often a complete screwdriver button replacement... In both the first and second cases, you can fix the problem yourself. Everything in order.

The screwdriver button is the main control element that performs several functions at once:

Turn on / turn on the instrument;
Switching the direction of rotation;
Smooth engine start;
Speed control.

However, each of the controls built into the button block cannot work correctly by itself. Except for the direction of rotation switch, which is usually a separate function block.

Video (click to play).

In most cases, the body consists of three conventional compartments, in which the working units and mechanisms are located.

In the lower part of the body there is an on / off control unit and an electric motor speed control unit.
In the middle part there is the "trigger" of the smooth start (the deeper you press it, the higher the rotation speed of the cartridge). When pressed, the button slides in a special block along the guides, a variable resistor is responsible for adjusting the speed.
In the upper part there is a reverse button - a switch for the direction of rotation of the cartridge. The direction is reversed by reversing the polarity of the voltage applied to the switch.

This is approximately how all control units of screwdrivers of different brands are arranged. To familiarize yourself with the device of a button of a specific instrument model in more detail, we recommend that you study screwdriver button diagram (it is in the instructions).

To diagnose and repair a screwdriver, you will need the following tools:

As a result of active use of any power tool, dirt inevitably accumulates inside its body.

Once in the control unit, it prevents the full movement of the "trigger" and blocks it.

Therefore, before going to the store for a new block, you should try to clean the old one. The carbon deposits formed on the contacts should also be cleaned with fine sandpaper. If the button is non-separable, the entire unit will have to be replaced.

Diagnostic steps:

We disassemble the tool body. To do this, we disconnect the battery, unscrew all the screws (they can be hidden behind decorative overlays that will have to be removed).
We check the serviceability of the electric motor.To do this, disconnect two power wires from the control unit and connect them to the battery contacts (the engine should start working).
We disassemble the screwdriver button. To do this, squeeze the plastic latches and separate the two parts of the button housing.
We make a visual inspection of the state of the button for dirt and damage.
Next, you need to carefully assemble the screwdriver button, install it in place and test.

VIDEO INSTRUCTION

If the cleaning of the control unit did not work, it is necessary to replace the entire button unit.

Disassemble the screwdriver (the process is described above);
Install the new button in place of the old one;
Connect the motor to the button terminals (polarity is not necessary in this case);
Assemble the screwdriver by carefully placing the wires in the case.

It is very important to choose a button for a specific model of a screwdriver, since with all the external similarity and visual correspondence, the part may not fit into the grooves. Typically, new buttons are sold complete with battery terminals and a transistor.

Many people probably have electric screwdrivers, battery-powered flashlights, etc. at home. in which the batteries do not pull.

My screwdriver has a fully charged battery for a couple of three screws.

Batteries in a screwdriver, cadmium in flashlights, as a rule, lead, all of them are now quite problematic to get for replacement. That will give us the conversion of devices to lithium.

1. Simplification of charging. Charging from micro usb, no need to look for where you put your own charger or where the wire from the flashlight.

2. The lithium battery is easier to find. For example, I generally took cans from an old battery from a laptop (you can find it either for free or for minimal money).

3. When replacing cadmium. There is no memory effect and you can charge at any time without waiting for a complete discharge.

4. Bigger than the standard battery capacity, often even when using a used unit. cans.

And so what we need.

1. Charge controller board, for example, on the TP4056 microcircuit. It is sold by the Chinese on Ali ebau and other sites. A clip will be sent for a dollar.

Available in two versions with and without overdischarge protection. It makes sense to use it with protection if there is no protection board in the battery itself. For 18650 batteries and the like, the protection board is usually installed on the negative terminal, if the negative is not made of metal, but of PCB glass, then this is the protection board.

The boards are similar in size. (left with protection from right without)

WARNING. For an electric screwdriver, battery protection cannot be used with a protection current of about 3A, and although the total consumption of a screwdriver is not large, inrush currents cut out the protection.

Here is a circuit board with battery protection (found on the Internet). Also in the appendix I will add documents for microcircuits.

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The Chinese boards have a charge current of 1A if you want to charge from a computer port or from a weak charge, you must reduce the current to at least 0.5A. To do this, you need to replace the 1.2K resistor connected to the second leg of the TP4056 microcircuit with a larger resistor, for a current of 0.5A with approximately 2.4K resistance (the table of charging currents depending on the resistance is given in the document on the microcircuit).

I am planning on being able to charge from a computer and am replacing this resistor. Soldering and cleaning the pads.

Since it was only available with a nominal value of 2.2K, it received a charge current of 0.52A. What I considered acceptable for charging from a computer port.

2. The battery can be either bought a new one or removed, for example, from an old laptop battery.

My battery contained 6 cans connected in pairs. It is advisable to disconnect all the batteries (one of the cans was completely dead in one of the pairs) and measure the residual voltage. If there is a choice, then take banks with a large residual voltage, as a rule, and they also have more remaining capacity, although of course it is better to measure the real capacity. The battery was at 4000 mA i.e. at 2000 mA per jar, the residual capacity was noticeably 1200-1400 mA, depending on the jar.

Metal strips of contacts are welded to the batteries; they do not need to be torn off, but simply cut between the banks. It is convenient and safe to solder wires to them.The metal on the contacts of the batteries themselves is harder to solder and if you hold the soldering iron for more than a second, then there is a danger of overheating the battery, which will disable it until it burns out.

3. Wiring soldering iron tester, files, glue gun, etc.

We remove the batteries and standard charging for them. (if there is a backlight and for the flashlight it is desirable to measure the current of the LEDs on a fully charged battery)

Thinking about where to place the new battery and charging board.

Now, one of the longest stages is the finalization of the case.

To speed it up, it is better to use mechanization.

For example, Chinese cutters.

But I like the old Soviet ones better, they have better control and are less distracted. But unfortunately on sale they are more difficult to find.

We choose the extra plastic, making sure that the mini USB connector is minimally recessed.

We solder the circuit by connecting the battery and charging. And we check the operation of the charging and screwdriver, also if there are lighting LEDs, we measure the current consumption from lithium and the resistance of the damping resistor.

If the current of the lighting LEDs is very different from the current on the standard batteries, then we adjust the resistance of the balancing resistor. I soldered another resistor in parallel.

Next, degrease the body and all the parts with isopropyl alcohol or good gasoline in the shoe (ethyl alcohol does not degrease). And we fill in all the components from the hot glue gun. Excess, if that is not difficult to cut off with a knife.

After assembly, pour glue from a pistol into the holes that are intended to indicate charging.

When the glue has cooled down a little, it is easy to clean off the excess. As a result, the glue acts as a light guide and the battery is clearly visible when charging.

Alteration of another screwdriver. Now the battery can be charged without removing it from the screwdriver.

The battery is removable. (After the alteration, a micro USB connector and a charge indicator appeared on it)

A set of cadmium batteries and contacts were attached directly to the batteries.

With the help of hot melt glue I made a clip of contacts.

I placed the charger in the back and soldered all the components.

Redesigning the flashlight with a lead battery and charging from the mains took even less time since nothing had to be undermined.

The screwdriver belongs to the category of tools that are often used not only when performing construction and repair work, but also in everyday life. Over time, any mechanisms tend to break, which happens with screwdrivers. If such a thing happened, then there is no need to rush to throw away the tool, since you can perform an independent repair of the screwdriver. From this article, you will learn how to have a screwdriver repaired without the help of specialists.

To start repairing a screwdriver with your own hands, you should familiarize yourself with its design. The main element of the screwdriver is the electric motor. Screwdrivers are of both mains and battery types. The use of a network screwdriver is used less often, due to such a drawback as the need to connect the tool to a 220V network. Battery-type tools are more popular, as they allow you to carry out repair work not only at home, but also outside it.

The main components of the cordless screwdriver are:

Frame. Usually all screwdrivers are made of durable plastic.
Start button. It is designed in such a way that the number of revolutions of the cartridge depends on the force of pressing on it.
Electric motor. In cordless tools, single-phase motors of the collector type and direct current are used. The motor is a rotor, a stator in the form of magnets, and a brush assembly.
Reducer.
Force regulator.
Reverse switch.
Battery. As a rule, it is removable and often comes with a duplicate product.
Cartridge. Keyless chucks are usually used.

Some models are additionally equipped with LED illumination lights and battery charging indicators. Returning to the problems with the screwdriver, it should be noted that any of the above items can cause the tool to malfunction. What is needed for the repair? The first step is to find the cause of the breakdown, and then make an appropriate decision to eliminate it. The tool can be divided into two parts: electrical and mechanical. Initially, it is required to find out what the problem of the inoperability of the screwdriver is: in mechanics or electrics. It will not be difficult to do this, so we will consider the breakdown in more detail.

It is possible to identify mechanical malfunctions of screwdrivers by such a sign as the audibility of the functioning of an electric motor. When you press the start button, you can hear the signs of the electric motor, but at the same time the tool holder does not rotate or during rotation you can hear the characteristic sounds of a malfunction.

The device of the screwdriver is quite simple, but a significant drawback is that all the elements are practically 2-3 times smaller than on an electric drill. Mechanical possible breakdowns of the screwdriver include the following malfunctions:

It should be noted that the small size of the mechanical part of the tool somewhat complicates the process of repairing the tool, so be sure to be careful when carrying out repair work.Unlike drills, screwdrivers operate primarily on batteries. This means that different motors are used in the construction of these tools. Determining the malfunction of the electrical part of the screwdriver is not difficult. If the battery is charged, but when the "Start" button is pressed, the sound of the electric motor is not heard, then the cause is a breakdown in the electrician. Consider the main types of electrical screwdriver malfunctions. Image - Cordless screwdriver DIY repair

Now you know the main signs and types of screwdriver malfunctions. To repair it, you do not need to be a specialist, but just stock up on tools and free time.In terms of functionality and dimensions, the cordless screwdriver is in the middle between a conventional screwdriver and a screwdriver. Due to its lightness and compactness, this electric screwdriver works quickly with different fasteners compared to a manual screwdriver. It is used for the assembly of furniture, repair and maintenance of various equipment. Plus, the tool can be made by hand.The cordless screwdriver is used for screwing and unscrewing various fasteners into non-solid materials, for example, made of wood. The screwdriver battery is built into the handle, so the tool is small. The device can be used where there is no need to drill and tighten the fasteners too much, to work in narrow places and openings in which a screwdriver cannot fit.The rechargeable screwdriver is used in the assembly of furniture, installation of windows, repair of household and computer equipment, maintenance of cars, when performing small household work.The tool is characterized by parameters that you need to know about:

battery voltage. This characteristic is equivalent to the power of network devices. With increasing voltage, the device has a greater efficiency. The maximum value is reached with a fully charged battery. Decreases over time until the screwdriver can still be turned on. During storage, the voltage also decreases. Therefore, after a long period of non-use of the instrument, it must be fully charged;

battery type. There are three types of batteries used in screwdrivers:

nickel-cadmium Ni-Cd. Cheap, resistant to different temperatures. Due to their low resistance, they have high charge and discharge currents. They can be charged about 1000 times.But they are toxic due to cadmium, have a memory effect and a small capacity;
nickel metal hydride Ni-MH. The memory effect is less than that of nickel-cadmium. Due to their higher density, their capacity is 25–35% larger than previous ones with the same dimensions. Not harmful to the environment. But they have less charge. It is undesirable to discharge them to the end;
lithium-ion Li-Ion. They have the highest capacity. Due to this, they are reduced in size. They have no memory effect at all. Discharges very slowly during storage. But they also have their disadvantages. Higher cost, shorter service life and poorly tolerate high and low temperatures;
Battery capacity. The operating time of the screwdriver depends on it. At high speeds under load, energy is consumed faster, so the operating time also depends on the intensity. Lithium-ion batteries may not be fully recharged for fast charging;
battery device. There are two types of battery for a cordless screwdriver:
- removable. Installed in powerful devices, charges quickly. Allows you to work continuously if there is a replaceable battery;
- non-removable. located in the housing. Such a tool is light in weight, size and cost. It is convenient for them to use. But the capacity is also small, so you have to charge it often. This can lead to work interruptions. After all, the battery cannot be removed from the case, and another cannot be put in its place;
- charging time. Depends on the type of battery and ranges from 1 to 10 hours;
- maximum torque. It determines the force of rotation. When interacting with the material, the moment decreases. Using the tool at high loads leads to a quick loss of battery power and wear of the screwdriver elements;
- maximum number of revolutions. This is the rotation of the shaft. With a high-speed screwdriver, self-tapping screws can be easily screwed in.
The main elements of the cordless screwdriver:
1. Power button.
2. Electric motor.
3. Reducer.
4. Spindle with tip. Some models have a cartridge.
5. Battery.
6. Power and battery indicator.
Cordless screwdriver device

When the power button is pressed, the circuit is closed. The battery supplies energy to the engine. He starts to work. The rotation is transferred to the gearbox and to the tip with a hole. A bit or adapter is inserted into it to enable the use of nuts.

A screwdriver can replace a cordless screwdriver, but a screwdriver is not always. Although these tools are similar in appearance, they have significant differences.

This is not to say that this or that instrument is better than the other. The screwdriver is good for its power and drilling capability. And the screwdriver is convenient for its small dimensions and weight.

Compare your needs and the money threshold for buying. Check out the types and technical characteristics of screwdrivers.
Types of shape of cordless screwdrivers:
Cordless screwdrivers are classified into household and professional. The latter are distinguished by greater power due to their high torque and rpm.

When buying a tool, pay attention to the technical characteristics and additional features:

A number of the most popular models for home and domestic use stand out:
The screwdriver is a mobile tool that makes it easier to work with fasteners and screw connections.Until recently, cordless screwdrivers could only be found in the arsenal of professionals, but with the advent of inexpensive household models on the wide sale, their popularity has increased dramatically.

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Unlike an expensive professional tool, budget counterparts have a smaller resource, which is why they often fail.

One of the weakest points of a household screwdriver is the start button and reverse switch. As practice shows, it is they that break most often.

As a rule, it all starts with the fact that the soft start function stops working, then a stronger pull on the "trigger" is required to start the electric motor.

Over time, the tool ceases to respond to any manipulation altogether. Often there is a problem of the opposite nature, when the motor starts to work spontaneously.

In some cases, to eliminate the defect, it is enough to disassemble the tool and clean it, although more often a complete screwdriver button replacement... In both the first and second cases, you can fix the problem yourself. Everything in order.

The screwdriver button is the main control element that performs several functions at once:
- Turn on / turn on the instrument;
- Switching the direction of rotation;
- Smooth engine start;
- Speed control.
However, each of the controls built into the button block cannot work correctly by itself. Except for the direction of rotation switch, which is usually a separate function block.

In most cases, the body consists of three conventional compartments, in which the working units and mechanisms are located.
1. In the lower part of the body there is an on / off control unit and an electric motor speed control unit.
2. In the middle part there is the "trigger" of the smooth start (the deeper you press it, the higher the rotation speed of the cartridge). When pressed, the button slides in a special block along the guides, a variable resistor is responsible for adjusting the speed.
3. In the upper part there is a reverse button - a switch for the direction of rotation of the cartridge. The direction is reversed by reversing the polarity of the voltage applied to the switch.
This is approximately how all control units of screwdrivers of different brands are arranged. To familiarize yourself with the device of a button of a specific instrument model in more detail, we recommend that you study screwdriver button diagram (it is in the instructions).

To diagnose and repair a screwdriver, you will need the following tools:

As a result of active use of any power tool, dirt inevitably accumulates inside its body.

Once in the control unit, it prevents the full movement of the "trigger" and blocks it.

Therefore, before going to the store for a new block, you should try to clean the old one. The carbon deposits formed on the contacts should also be cleaned with fine sandpaper. If the button is non-separable, the entire unit will have to be replaced.

Diagnostic steps:
1. We disassemble the tool body. To do this, we disconnect the battery, unscrew all the screws (they can be hidden behind decorative overlays that will have to be removed).
2. We check the serviceability of the electric motor. To do this, disconnect two power wires from the control unit and connect them to the battery contacts (the engine should start working).
3. We disassemble the screwdriver button. To do this, squeeze the plastic latches and separate the two parts of the button housing.
4. We make a visual inspection of the state of the button for dirt and damage.
5. Next, you need to carefully assemble the screwdriver button, install it in place and test.
VIDEO INSTRUCTION

If the cleaning of the control unit did not work, it is necessary to replace the entire button unit.

Disassemble the screwdriver (the process is described above);
Install the new button in place of the old one;
Connect the motor to the button terminals (polarity is not necessary in this case);
Assemble the screwdriver by carefully placing the wires in the case.

Hey! Today we will repair the screwdriver battery. Did you know that the history of the creation of a screwdriver goes back to the deep Middle Ages - already in the 15th century, when the knights put on armor before the battle, and the squires helped them twist parts of the armor, guess what? A screwdriver!

This continued for a long time, until in 1907 the Canadian inventor Peter Robertson patented the Robertson screw with a standard square hole, into which the tip of the screwdriver was inserted. Since that time, screws began to be produced on an industrial scale and used in households. Later, in 1934, inventor Henry Phillips redesigned the head of the screw and a Phillips screw was introduced into which the corresponding screwdriver was inserted. By that time, the engine had already been invented and the idea of creating a "screw and screw rotator" was in the air. However, there were big problems with the batteries - their weight and dimensions. The problem was solved only in the 1980s, when the first nickel-cadmium Ni-Cd and lithium-ion Li-Ion rechargeable batteries appeared.

The USA and Japan were the first to master the production of household and professional cordless drills and screwdrivers. All this happened thanks to the emergence of new energy-intensive batteries of electricity. We will urgently change them inside the Interskol DA-10 / 10.8 ER cordless drill-screwdriver that fell into my hands. The malfunction was like this - when the button was pressed, the engine simply did not spin, but the LED lit up, though the light was weak.

Let's start repairing the screwdriver battery. We remove the battery from the handle of the screwdriver and unscrew the three self-tapping screws that are located under the sticker at the bottom.

After unscrewing the screws, carefully push back the hooks of the latches, as in the photo. And remove the lower part of the plastic battery case.

Inside we see lithium-ion cans Chinese company HighStar model ISR18650-1300 Li-Ion. This means that the batteries have never been changed. Because it is known that Interskol purchases batteries from this company and inserts them into almost all of its cordless tools.

The photo below shows the insides of the screwdriver battery in all its glory with three cans, which were produced already in 2011. These batteries lasted five years during active use at a construction site. So the result is very decent. Usually they die earlier, probably in cold weather they were not exploited.

To replace the battery banks, you need to disassemble it even more. I advise you to remember the location of the plus, minus and charging contacts so as not to confuse the wires when reassembling.

Pay attention to the voltage control board on the batteries - especially often stabilizers and protective diodes fail on it. It is imperative to ring suspicious radioelements on this board with a multimeter.

We check the voltage at the output of the battery - it turned out 4.4 volts, and it should be 3.7 x 3 = 11.1 volts in the norm and 10.8 volts with the minimum charge of the batteries. In general, the banks are dead - they need to be changed unambiguously.

This can be done in several ways - you can unsolder the wires that go to the board.

You can also simply remove the contacts from the top battery cover. The photo shows the shape of the curved contacts, so you can easily remove them yourself.

Under the plastic cover, we see how the batteries are connected to each other. Their spot welded... This solution is used in almost any battery of another tool. This is a safe and gentle battery connection. At the same time, the destructive heating of the lithium batteries themselves is minimal.

Gently tear off or bite off the metal tape with pliers to disconnect the cans from each other. From the side of the board, they were also connected with a tape and glued to a cardboard gasket. This is done so as not to short-circuit anything on the board. Remember to put it back in place when reassembling the battery.

Due to the lack of a spot welding device, new lithium-ion batteries will be soldered very quickly with a well-heated powerful soldering iron. We remember that heating lithium-ion batteries reduces their service life and is generally explosive.

Pay particular attention to the condition of the wires inside the battery. They can be broken or frayed. They need to be qualitatively isolated or replaced with fresh ones. Since I was repairing a screwdriver battery on the road in the field, I had to apply a brilliant invention of the engineering mind. He took out a blue radio-technical electrical tape.

When disassembling the battery of the Interskol DA-10 / 10.8 ER screwdriver, I was pleasantly surprised - a thermal sensor was installed in the budget screwdriver to control the temperature of the batteries. It turns out that when the lithium cans overheat, the protection circuit turns off the power until the temperature returns to normal. True, the owner never managed to drive him into such a regime. We carefully tear off this thermal sensor so as not to break it - then we will place it in the same place on new cans.

can be done in different ways, for example with thick wires. I decided to solder a torn-off metal strip taken from old cans. First, I tinned the tapes in the places of future contacts on both sides. Later I tinned the battery contacts with a well-heated soldering iron with a drop of solder. But so that they do not get too hot - let them cool down. Then he pressed the tape to the contacts of the cans and soldered the tape again without severe overheating of the battery cans.

The minus leads are the hardest to solder, but with a good flux, things go very quickly. True, then it is better to wash the flux afterwards to clean the insides of the battery.

Now comes the most important thing. What batteries were used when repairing the battery of the Interskol DA-10 / 10.8 ER screwdriver, you ask? Well, I won't hide. These were the most Chinese of the cheap cans that the owner of the device honestly bought in the store. Batteries of standard size 18650 firm Bailong with a fictitious capacity of 8800 mAh. This is of course a laugh and God forbid that they have a 2200 mAh battery. Judging by how long the screwdriver worked after repair on a full charge. I would reduce this figure by a factor of two. But nevertheless, the screwdriver was urgently repaired and it pleases the owner.

When assembling, do not forget to replace the cardboard gasket between the banks and the board. This is so that the fresh soldering does not short-circuit anything on the board.

This completes the repair and restoration of the lithium-ion battery of the Interskol DA-10 / 10.8 ER screwdriver. Almost all batteries are repaired in much the same way. popular manufacturers of screwdrivers: Bosch, Makita, DeWALT, Metabo, Hitachi, Elitech, Skil and my favorite Bison. This concludes my story about repairing a screwdriver battery. Ask questions in the comments. Better yet, in the appropriate thread on our forum or write to the Solder Master personally by mail.

Best regards, Solder Master. Happy repairs!

A screwdriver can be safely ranked as a tool that quite often has to be used not only in everyday life, but also for work on construction sites. But, like any complex technical accessory, the product can break. We will consider how to repair a screwdriver on our own in this text.

The equipment in the construction market, where screwdrivers take a separate place, is quite large. Many models have individual criteria, assembly quality and cost. However, most of the models are characterized by basic principles of operation and internal execution.

The basic elements of any screwdriver include:

the presence of an electric motor;
planetary reductor;
adjustable function button "Start";
reverse switch;
effort regulator;
power unit.

The electric motor is powered by a direct current network, structurally represented by a cylindrical shape. Inside is an anchor with brushes and magnets. The peculiarity of the electrical circuit of the motor assumes that the direction of the supply voltage flow will be directed to the brushes. When the supplied polarity changes, the motor reverses.

The planetary gearbox is an important element capable of converting the high-frequency vibrations of the electric motor shaft into the low-frequency revolutions of the chuck shaft. Typically, these parts are manufactured from wear-resistant plastic or metal. Many screwdrivers are equipped with 2 speed gearboxes. Switching to the first speed mode is necessary for working with self-tapping screws, and at the second speed you can drill in wood, plastic base or metal.

The "Start" button starts the device. It is able to control the number of revolutions, providing the ability to select the optimal rotation speed for the chuck shaft. Correspondingly, pressing forcefully will power the engine at high rpm, and as the pressing force decreases, the power criterion will weaken.

The reverse switch is required to carry out operations to change the rotational direction of the screwdriver motor. This functionality is convenient to use not only for tightening, but also unscrewing screws.

Regarding the force regulator, we can say that it determines the speed of tightening the screws. In current models, a 16-step adjustable graduation is provided, which allows you to determine with maximum accuracy and convenience what tightening speed is relevant when working with various materials.

The power supply for the screwdriver is oversized rechargeable batteries, where the power supply voltage (depending on the model device) can vary from 9 to 18V.

If at some point you find that your screwdriver does not turn on, then most likely it has some kind of malfunction. Practical experience shows that the inoperability of a tool can be observed for two reasons:

the breakdown is associated with the electronics of the device;
breakage can be mechanical.

Understanding the objective causes of electrical breakdown, one can note its characteristic signs:

the product stops responding to switching on;
the device has ceased to regulate the speed;
the reverse operation failed.

Mechanical problems with a screwdriver include problems with wear of internal parts, for example, a characteristic ratchet of the mechanism is heard. As a rule, a faulty screwdriver will begin to make characteristic sounds, where, for example, bushings have been worn out or a bearing has collapsed. This often happens on a hummer instrument.

For example, if the tool stops turning on, then initially you need to check the health of the battery. If, when basing the device on charging, the breakdown has not disappeared, then you will have to arm yourself with a multimeter and start scanning the device in search of the root cause. First of all, take a look at the voltage value indicated on the device case and compare it with the measurements on the battery. The data should be roughly the same.If the voltage is too low, then most likely the problem is hidden in the charger or battery pack.For example, the charger can be checked using a multimeter, plugging it into the network, and taking measurements at the terminals of the device at idle. It is important that the voltage criterion is slightly higher than the nominal one. In a situation where there is no voltage, then, unambiguously, the culprit of the breakdown is the charging unit. Interskol screwdrivers "suffer" from this rather frequent problem. In general, fixing the defect will require specific knowledge of electronics or a new unit will need to be purchased.If you find a battery problem, for example, with a Makit screwdriver, you can open this block with your own hands, where the supply elements are located. As a result of opening, research of the connecting wires should be carried out and the quality of the soldering should be ensured. If no visible defects are found, then using a scanner, you should measure the voltage in each element. Values should indicate 0.9 - 1V voltage power. If a block with a low voltage indicator is found in a row, then it must be replaced.

When everything is in order with the battery and charging goes without problems, but the tool refuses to be activated, then it will check the serviceability of the device button. To do this, you will have to disassemble the device and at its terminals coming from the button, you should measure the voltage with a multimeter, which comes at the input of the button. It is necessary to carry out the operation with an active battery. If there is a signal, then the battery must be removed and its contacts must be short-circuited using the clamps. On the multimeter, you must switch to Ohm mode. The screwdriver button is clamped all the way and measures the output voltage. If the value of the resistance readings on the device tends to zero, then the button works properly. This means that the problem should be looked for in the brushes or other modules of the electric motor. If a signal break is detected, the button is recommended to be repaired, thereby returning the screwdriver to the working order of the tools.

Quite often, problems with buttons are associated with poor contact at the terminals. You can simply perform the procedure for cleaning the contacts with sandpaper and the problem will be solved. The main thing is to do everything carefully in the process of disassembling and assembling the device, without losing parts.

A broken gearbox is one of the mechanical problems with a screwdriver. Some of the most common problems with the reduction unit include:

physical curvature of the axis of the reduction shaft;
obvious defect of the working surface of the gears;
failure of the shaft support sleeve or original bearing;
breakage of the pin where the satellites are fixed.

To correct these defects, it will be necessary to physically replace the defective parts, therefore, this type of repair should be entrusted to qualified specialists who are able to correctly and accurately diagnose the breakdown and eliminate it.

Video (click to play).