LED bulbs are constantly burning out. Reasons for frequent burnout of LED lamps. LED lamps - design feature

LED bulbs are popular for many reasons. LED light sources are characterized by long service life, economical power consumption and reliability. However, in addition to advantages, LED bulbs also have disadvantages. The most common problem consumers face is when an LED light is on when the switch is off.

Features of LED lamps

LED bulbs have a slightly more complex internal structure than conventional incandescent bulbs.

The main elements of the LED lamp:

1. Nickel-plated brass plinth. These materials avoid corrosive processes and also ensure good contact with the chuck.
2. The base of the plinth is made of polymer (polyethylene terephthalate). The material protects the body of the device from electricity.
3. The driver is based on a galvanically decoupled current regulator modulator circuit. The task of the driver is to create conditions for stable operation of the light source even in the event of power surges.
4. The radiator is manufactured from anodized aluminum alloy. The coating allows heat to be removed from those surfaces of the lamp for which overheating is contraindicated.
5. Aluminum PCB. The component guarantees the required temperature regime for the chips due to heat transfer to the heatsink.
6. Chips. They are a key element of the system. They are also called diodes.
7. Diffuser. It is a glass hemisphere with the maximum level of light diffusion achievable within the technology.

The principle of operation of LED lamps is based on the release of photons. This occurs as a result of permanent change and the emergence of multiple combinations of electrons. Continuity of change is ensured by the presence of conductors. Resistors or current limiting devices are used to optimize the process.

Recently, more advanced systems have appeared that provide high consumer characteristics. In such bulbs, diode bridges are used. However, the prices for such lamps are much higher than for old-style products.

Why does the LED lamp light up when the switch is off?

There are several common reasons for LED lights to glow when the switch is off:

1. Poor quality insulation materials.
2. Using an illuminated switch.
3. Poor quality light bulb.
4. Wiring problems.
5. Features of the power supply circuit.

Poor insulation

Insufficient quality insulation on any part of the electrical circuit often causes problems with light. This malfunction has the most serious consequences, because in order to fix it, it will be necessary to break the finishing layer on the walls in order to replace the insulation.

To test the insulation for leakage current, high voltage is applied to the mains for 1 minute. This is necessary to simulate the conditions under which breakdowns occur in the electrical circuit.

Using illuminated switches

The answer to the question of why the LED lamp glows when the switch is off is to use a backlit switch. In the interior of such a device there is a light diode with a current limiting resistor. The reason for the glow of the lamp is that even when the contact is disconnected, voltage still passes through them. However, the lamp does not light up at full power, since there is a current-limiting resistor in the circuit.

The lamp shines either constantly (if the current is sufficient) or intermittently (blinking because the current is too weak). However, even in the latter case, the current is sufficient to recharge the capacitor. As soon as sufficient voltage accumulates in the capacitor, the stabilizer microcircuit turns on, and the light immediately lights up. The operation of the lamp in this mode leads to its rapid wear, since the number of operating cycles for the microcircuits is finite.

In this case, there are several methods for eliminating the problem of a luminous light bulb. The easiest way is to remove the backlight from the switch. To do this, dismantle the case and remove the wire directed to the resistor or light diode. It is also possible to replace the switch with another one that does not have a backlight function.

Another way to solve the problem involves soldering a shunt resistor in parallel to the light bulb. You will need a 2 watt resistor with a resistance of up to 50 kΩ. If you do this, the current will flow through this resistor, and not through the light bulb power supply driver. Installing a resistor is straightforward. You just need to remove the cover and fix the resistance legs in the terminal block for connecting the mains conductors.

It is enough to connect one resistor to the switch, you do not need to hang them on each lamp.

In the absence of sufficient knowledge in electrical engineering, it is easier to do. To do this, put an ordinary incandescent lamp in the lighting fixture. The spiral of the light bulb, when turned off, will serve as a shunt resistor. However, this option is only suitable if there are several cartridges in the lighting device.

Poor quality light bulb

Often the cause of the malfunction is an insufficient quality lamp. In this case, there is only one way to solve the problem - to replace the product with a better one.

Wiring problems

If mistakes are made during the installation of electrical wiring, one of the consequences of this may be the glow of the lamp when the switch is already off. This situation happens when zero is mixed up with phase, and even after disconnecting the wires remain under phase.

The situation should be corrected not only in order to get rid of a light bulb that is shining without the need. This is also necessary to avoid electric shock when replacing the lamp.

Features of the power supply circuit

To provide a brighter glow and reduce light ripple, a capacitor with a high capacitance is sometimes added to the power supply circuit. This leads to the fact that even when the switch is off, there is still sufficient charge in the switch to allow the LEDs to glow.

1. Carefully read the instructions that come with LED lamps. It contains the rules for using the product.
2. Some convenient lighting functions are difficult to match with LED bulbs. Timers, light intensity controllers, photovoltaic cells, backlighting are often the cause of LED malfunctions.
3. Pay attention to the dimensions of the radiator. This element is responsible for the removal of a sufficient amount of thermal energy, which is released when the light is on. The dimensions of the radiator and the wattage of the lamp must be consistent with each other.
4. Radiator material. The best choice- aluminum radiator. Ceramic and graphite products have proven their worth.
5. The quality of the joint between the lamp body and the base. If there are obvious mechanical defects at the junction, the likelihood of problems with the glow of the lamp when the switch is off increases. The base must be securely and without backlash fixed to the body.
6. Ripple level. The correct glow is uniform, without any flicker. However, it is difficult to notice irregularities in the light. This is where a mobile phone video camera comes in handy - it makes it much easier to see the flicker.

LED lamp manufacturers claim that these light sources are capable of uninterrupted operation from 30,000 to 100,000 hours, then why burn out LED lamp? The answer lies in the ill-conceived and cheap design of the fixtures. What should you look for when buying LED bulbs and how to test the quality of a product at home?

The choice of LED lamps for the home - two tricks that buyers are led to

There are two main reasons for its popularity. The first is low power consumption. According to manufacturers, such bulbs give out 100 W and consume only 10-12 W, which is 10 times less than standard incandescent lamps and 3 times less than energy-intensive fluorescent lamps. Second, the service life of LED lamps for standard models is 25,000-30,000 hours. Taking into account that on average the luminaire will work 6-7 hours a day, the light bulb should last for 11-13 years. Other advantages of these bulbs include the absence of mercury, the durability of the materials and the ability to create lighting with a different color spectrum.

And now about the disadvantages that overlap the advantages. First of all, the high price. Ordinary bulbs with a consumption of 4-9 W will cost from 300 to 2000 rubles, and LED lamps - from 5500 rubles. Let's go back to the lifespan of LEDs and answer the question: is it true? The answer is no. Numerous consumer complaints are direct evidence of this. Simple arithmetic shows that an LED light bulb should last about 11 years, while the manufacturer gives it a 3-5 year warranty.

Already in the first year of operation, individual LEDs begin to burn out and gradually pull along all the other bulbs connected by a common chain. You also need to take into account that in order to get the usual lighting, you will need to purchase more bulbs, since LED lamps have a directional emission spectrum. Therefore, before buying expensive LED bulbs, think carefully about whether they can pay off during their service.

Tricks with a current stabilizer and power supply - manufacturer secrets

Poor build quality, which is inherent in most products of the Chinese series, is the main reason why bulbs burn out. Such lamps make attractive only externally, the internal content leaves much to be desired. The first thing that is often missing from most Chinese LED bulbs is the current regulator. The installation of this element maintains a constant current output even with an increase in the load in the network, the system does not overheat, the LEDs work stably. What are unscrupulous manufacturers doing? They replace the current stabilizer with a ballast power supply. It is not able to withstand a voltage drop in the network and an excess of the nominal heating temperature, so the bulbs burn out quickly.

The ballast power supply has another tricky function - the bright glow effect. The store will offer you just such LED bulbs. During testing, they will emit a bright and powerful luminous flux thanks to the built-in ballast power supply, where the output voltage is slightly higher than the nominal. However, at the end of the reserve, the brightness of the light decreases to 30% or the bulbs burn out completely.

Among other reasons why Chinese-assembled light bulbs often burn out, one can single out poor-quality soldering, a factory defect in parts and an incorrect wiring diagram.

Among the small wholesale deliveries of bulbs via the Internet, there are often products with very low quality. Such LED lamps are most often sold without names, they have a manufacturing defect (non-standard base, manual modification, poor soldering, improperly assembled circuit).

The quality of the components - what to look for?

Returning to the topic of the quality of parts that affect the operation of LED bulbs in luminaires, pay attention to the plastic housing, aluminum and other elements. The first thing that you feel when you take cheap light bulbs in your hands is light weight. If the mass of a standard 12 W LED lamp is about 50-60 g, it means that cheap thermoplastic and a thin aluminum radiator were used for its production. Such materials do not fit tightly in places of bending, LEDs overheat, and contacts oxidize and fail. Therefore, give preference to heavier bulbs weighing 100-120 g, where the likelihood of using quality parts is much higher. Pay particular attention to the external heat sink. It should be made of sturdy aluminum with ribbed edges through which heat dissipation passes. The matte plastic diffuser is a good heat conductor. Unlike frosted glass, it quickly builds up heat inside the case and slowly releases it, which also leads to overheating of the LEDs.

However, the most common problem that causes light bulbs to burn outquicklylike matches - partial application of thermal paste to an aluminum substrate. Unfortunately, this is the case in 90% of light bulbs. As a result of the uneven distribution of the composition, the LEDs overheat and the crystals are destroyed. The first to fail are the LEDs, which are located in the place where the thermal paste is completely absent. Remember, only when even distribution thermal paste over the entire surface of the plate will efficiently transfer heat to the cooling heatsink. If this problem is present and your LED bulbs have a removable diffuser, we recommend that you apply the thermal paste evenly by yourself.

Old electrical wiring - routine inspection

If the light bulbs in the chandelier burn out locally, for example, only in one room, it is worth checking the wiring. Inspect the wires in the junction box that go from the switch to the chandelier, the ceiling lamp connection diagram. When diagnosing, there should be no twisted or bare wires. For reliability and ease of connection, we recommend using WAGO terminal blocks. They are of two types - disposable and reusable. Use the second option. Thanks to a special lever, the contacts can be easily disconnected and the circuit can be tested for troubleshooting.

If the wiring is OK, inspect the chuck. If damage, burnt wires and parts are found, we change the old cartridge for a new one or clean the contacts and bend the wires. Replacing the cartridge will help eliminate the LED burnout problem. A leaking fit between the socket and the LED lamp often leads to malfunction of the lamp. Inspect the mounting screw and if loose, tighten it tightly. The tightness of the connection between the bulb and the socket will help stabilize the current and resistance in the system, preventing the risk of overheating.

Installation of LEDs in an apartment and a car - what to fear?

Cheap LED bulbs are sensitive to overheating. Therefore, it is important to install such light sources away from heating elements, to avoid a room with an elevated air temperature, such as a kitchen. When using a gas or electric stove, the room temperature can reach 30 ° C, provoking the destruction of crystals.

When buying LED strips of the SMD 5050 type for decoration, it is important to provide for the installation of fixtures on a durable aluminum profile, which will facilitate heat dissipation. If you neglect this rule, the LEDs will start to burn out one by one and the entire system will become unusable.

When installing LED bulbs in a car, make sure that there is a current stabilizer unit in them, and not a regular resistor. Otherwise, an increase in the power of the on-board network from 12 to 14 W negatively affects the operation of the LEDs. Therefore, when massively replacing halogen bulbs with LEDs, first test proven manufacturers - Feron, Jazzway, Camelion, Navigator, Gauss, and choose the appropriate option for yourself.

Due to their low power consumption, theoretical durability and price reduction, incandescent and energy-saving lamps are rapidly replacing. But, despite the declared service life of up to 25 years, they often burn out without even having served the warranty period.

Unlike incandescent bulbs, 90% of burnt out LED bulbs can be successfully repaired with your own hands, even without special training. The examples provided will help you repair a failed LED lamp.

Before undertaking the repair of an LED lamp, you need to present its device. Regardless of the appearance and type of LEDs used, all LED lamps, including filament bulbs, have the same structure. If you remove the walls of the lamp housing, then inside you can see the driver, which is a printed circuit board with radio elements installed on it.

Any LED lamp is arranged and works as follows. The supply voltage from the contacts of the electric cartridge is applied to the terminals of the base. Two wires are soldered to it, through which voltage is applied to the driver input. From the driver, the DC supply voltage is supplied to the board on which the LEDs are soldered.

The driver is an electronic unit - a current generator that converts the supply voltage into the current required for the LEDs to glow.

Sometimes, to diffuse light or protect against human contact with the unprotected conductors of the board with LEDs, it is covered with a diffusing protective glass.

About filament lamps

In appearance, a filament lamp is similar to an incandescent lamp. The device of filament lamps differs from LED lamps in that they use not a board with LEDs as light emitters, but a glass sealed gas-filled bulb in which one or more filament rods are placed. The driver is located in the base.

The filament rod is a glass or sapphire tube with a diameter of about 2 mm and a length of about 30 mm, on which 28 miniature light-emitting diodes, coated with a phosphor, are fixed and connected in series. One filament consumes about 1W of power. My operating experience shows that filament lamps are much more reliable than those made with SMD LEDs. I guess over time they will replace all other artificial light sources.

Examples of repairing LED lamps

Attention, the electrical circuits of the LED lamp drivers are galvanically connected to the mains phase and therefore care should be taken. Touching exposed parts of a circuit that is connected to the mains can result in electric shock.

LED lamp repair
ASD LED-A60, 11 W on the SM2082 chip

Currently, powerful LED bulbs have appeared, the drivers of which are assembled on microcircuits such as SM2082. One of them worked for less than a year and was repaired to me. The light went out haphazardly and then turned on again. When tapped on it, it responded with light or extinguishing. It became apparent that the problem was a poor connection.

To get to the electronic part of the lamp, you need to pick up the diffusing glass with a knife at the point of contact with the body. Sometimes it is difficult to separate the glass, since silicone is applied to the fixing ring when it is seated.

After removing the light-scattering glass, access to the LEDs and a microcircuit - the SM2082 current generator was opened. In this lamp, one part of the driver was mounted on an aluminum LED PCB and the other on a separate one.

External examination did not reveal defective rations or broken tracks. I had to remove the board with LEDs. To do this, the silicone was first cut off and the board was pried over the edge with a screwdriver blade.

To get to the driver located in the lamp housing, it was necessary to unsolder it, warming up two contacts with a soldering iron at the same time and moving it to the right.

On one side of the driver PCB, only a 6.8 μF 400 V electrolytic capacitor was installed.

On the reverse side of the driver board, a diode bridge and two series-connected resistors with a nominal value of 510 kOhm were installed.

In order to figure out which of the boards the contact is missing, they had to be connected, observing the polarity, using two wires. After tapping on the boards with the handle of a screwdriver, it became obvious that the malfunction lies in the board with the capacitor or in the contacts of the wires coming from the base of the LED lamp.

Since the soldering was not suspicious, I first checked the reliability of the contact in the central outlet of the base. It can be easily removed if you pry it over the edge with a knife blade. But the contact was reliable. Just in case, I tinned the wire with solder.

It is difficult to remove the screw part of the base, so I decided to solder the soldering wires from the base with a soldering iron. When touching one of the rations, the wire was exposed. There was a "cold" soldering. Since there was no way to get the wire to strip it, we had to grease it with active FIM flux and then re-solder it.

Once assembled, the LED lamp emitted light steadily despite being hit by a screwdriver handle. Checking the luminous flux for pulsations showed that they are significant at a frequency of 100 Hz. Such an LED lamp can only be installed in luminaires for general lighting.

Driver wiring diagram
LED lamp ASD LED-A60 on a chip SM2082

The electrical circuit of the ASD LED-A60 lamp, thanks to the use of a specialized microcircuit SM2082 in the driver for stabilizing the current, turned out to be quite simple.

The driver circuit works as follows. The AC supply voltage is fed through fuse F to a rectifier diode bridge assembled on the MB6S microassembly. The electrolytic capacitor C1 smooths out the ripple, and R1 serves to discharge it when the power is turned off.

From the positive terminal of the capacitor, the supply voltage is applied directly to the series-connected LEDs. From the output of the last LED, the voltage is applied to the input (pin 1) of the SM2082 microcircuit, the current in the microcircuit is stabilized and then from its output (pin 2) is fed to the negative terminal of the capacitor C1.

Resistor R2 sets the amount of current flowing through the HL LEDs. The magnitude of the current is inversely proportional to its rating. If the value of the resistor is reduced, then the current will increase, if the value is increased, then the current will decrease. The SM2082 microcircuit allows the resistor to adjust the current value from 5 to 60 mA.

LED lamp repair
ASD LED-A60, 11W, 220V, E27

Another ASD LED-A60 LED lamp, similar in appearance and with the same technical characteristics as the repaired one above, got into the repair.

When turned on, the lamp ignited for a moment and then did not shine. This behavior of LED lamps is usually associated with a driver malfunction. Therefore, I immediately proceeded to disassemble the lamp.

The light-diffusing glass was removed with great difficulty, since along the entire line of contact with the body, despite the presence of a retainer, it was abundantly greased with silicone. To separate the glass, I had to look for a pliable place along the entire line of contact with the body with a knife, but still, there was a crack in the body.

To gain access to the lamp driver, the next step was to remove the LED printed circuit board, which was pressed along the contour into an aluminum insert. Despite the fact that the board was aluminum, and it was possible to remove it without fear of cracks, all attempts were unsuccessful. The board was kept tight.

It also did not work to remove the board together with the aluminum insert, since it fit snugly to the case and was seated with the outer surface on silicone.

I decided to try to remove the driver board from the side of the base. To do this, first, a knife was pried out of the base with a knife, and the central contact was removed. To remove the threaded part of the base, it was necessary to slightly bend its upper flange so that the punching points disengage from the base.

The driver became available and moved freely to a certain position, but it was not possible to completely remove it, although the conductors from the LED board were sealed off.

There was a hole in the center of the LED board. I decided to try to remove the driver board by hitting its end through a metal rod threaded through this hole. The board has advanced a few centimeters and rested on something. After further blows, the lamp body cracked in the ring and the board with the base of the base detached.

As it turned out, the board had an extension, which with its shoulders rested against the lamp body. It looks like the board was shaped to restrict movement, although it was enough to fix it with a drop of silicone. Then the driver would be removed from either side of the lamp.

The voltage of 220 V from the lamp base through a resistor - the FU fuse is fed to the MB6F rectifier bridge and after it is smoothed by an electrolytic capacitor. Further, the voltage is fed to the SIC9553 microcircuit, which stabilizes the current. Parallel connected resistors R20 and R80 between pins 1 and 8 of the MS set the value of the LED supply current.

The photo shows a typical electrical circuit diagram given by the manufacturer of the SIC9553 chip in a Chinese datasheet.

This photo shows the appearance of the LED lamp driver from the side of the output elements installation. Since space allowed, to reduce the ripple factor of the luminous flux, the capacitor at the driver output was soldered to 6.8 uF instead of 4.7 uF.

If you have to remove the drivers from the body of this lamp model and you cannot remove the LED board, you can use a jigsaw to cut the lamp body in a circle just above the screw part of the base.

In the end, all my efforts to extract the driver turned out to be only useful for getting to know the LED lamp design. The driver was found to be working properly.

The flash of the LEDs at the moment of switching on was caused by a breakdown in the crystal of one of them as a result of a voltage surge when the driver was started, which misled me. First of all, it was necessary to ring the LEDs.

An attempt to test the LEDs with a multimeter was unsuccessful. The LEDs were off. It turned out that two light-emitting crystals connected in series are installed in one case, and in order for the LED to begin to flow, a voltage of 8 V must be applied to it.

A multimeter or tester, included in the resistance measurement mode, produces a voltage within 3-4 V. I had to check the LEDs using a power supply, supplying 12 V to each LED through a 1 kOhm current-limiting resistor.

There was no replacement LED available, so a drop of solder shorted the pads instead. It is safe for the driver to work, and the power of the LED lamp will decrease by only 0.7 W, which is almost imperceptible.

After repairing the electrical part of the LED lamp, the cracked body was glued with quick-drying superglue "Moment", the seams were smoothed by melting the plastic with a soldering iron and leveled with sandpaper.

For interest, I did some measurements and calculations. The current flowing through the LEDs was 58 mA, the voltage was 8 V. Therefore, the power supplied to one LED is 0.46 W. With 16 LEDs, it turns out 7.36 W, instead of the declared 11 W. Perhaps the manufacturer indicated the total power consumption of the lamp, taking into account the losses in the driver.

The service life of the LED lamp ASD LED-A60, 11 W, 220 V, E27, declared by the manufacturer, raises my doubts. In a small volume of a plastic lamp body, with a low thermal conductivity, significant power is released - 11 watts. As a result, the LEDs and the driver operate at the maximum permissible temperature, which leads to accelerated degradation of their crystals and, as a consequence, to a sharp decrease in their MTBF.

LED lamp repair
LED smd B35 827 ERA, 7 W on a BP2831A chip

An acquaintance shared with me that he bought five bulbs as in the photo below, and all of them stopped working after a month. He managed to throw out three of them, and he brought two, at my request, for repair.

The light worked, but instead of bright light, it emitted a flickering faint light with a frequency of several times per second. I immediately assumed that the electrolytic capacitor had swollen, usually if it fails, then the lamp begins to emit light, like a stroboscope.

The light-scattering glass was removed easily, it was not glued. It was fixed by means of a slot on its rim and a protrusion in the lamp body.

The driver was secured with two solders to a PCB with LEDs, as in one of the above lamps.

A typical driver circuit on the BP2831A microcircuit taken from the datasheet is shown in the photo. The driver board was removed and all simple radio elements were checked, everything turned out to be in good order. I had to start checking the LEDs.

The LEDs in the lamp were installed of an unknown type with two crystals in the case and inspection did not reveal any defects. Using the method of serially connecting the leads of each of the LEDs, I quickly identified the faulty one and replaced it with a drop of solder, as in the photo.

The light bulb worked for a week and was repaired again. Shorted out the next LED. A week later, I had to short-circuit another LED, and after the fourth I threw out the light bulb, as I was tired of repairing it.

The reason for the failure of bulbs of this design is obvious. LEDs overheat due to insufficient heat sink surface, and their resource is reduced to hundreds of hours.

Why is it permissible to short-circuit the terminals of burnt-out LEDs in LED lamps?

The driver of LED lamps, unlike a constant voltage power supply, outputs a stabilized current value at the output, not a voltage. Therefore, regardless of the load resistance within the specified limits, the current will always be constant and, therefore, the voltage drop across each of the LEDs will remain the same.

Therefore, with a decrease in the number of LEDs connected in series in the circuit, the voltage at the driver output will also decrease proportionally.

For example, if 50 LEDs are connected in series to the driver, and a voltage of 3 V drops on each of them, then the voltage at the driver output was 150 V, and if 5 of them are short-circuited, the voltage will drop to 135 V, and the current will not change.

But the coefficient useful action(Efficiency) of a driver assembled according to such a scheme will be low and power losses will be more than 50%. For example, for an MR-16-2835-F27 LED light bulb, you need a 6.1 kOhm resistor with a power of 4 watts. It turns out that the driver on the resistor will consume power that exceeds the power consumption of the LEDs and it will be unacceptable to place it in a small LED lamp housing, due to the release of more heat.

But if there is no other way to repair the LED lamp and it is very necessary, then the driver on the resistor can be placed in a separate case, all the same, the power consumption of such an LED lamp will be four times less than that of an incandescent lamp. It should be noted that the more LEDs connected in series in a light bulb, the higher the efficiency will be. With 80 series-connected SMD3528 LEDs, you will need an 800 Ohm resistor with a power of only 0.5 W. The capacitance of C1 will need to be increased to 4.7 µF.

Finding faulty LEDs

After removing the protective glass, it becomes possible to check the LEDs without peeling off the printed circuit board. First of all, a careful examination of each LED is carried out. If even the smallest black dot is found, not to mention the blackening of the entire surface of the LED, then it is definitely faulty.

When examining the appearance of LEDs, you need to carefully examine the quality of the rations of their conclusions. In one of the bulbs being repaired, there were four LEDs poorly soldered at once.

The photo shows a light bulb that had very small black dots on its four LEDs. I immediately marked the faulty LEDs with crosses so that they could be clearly seen.

Defective LEDs may or may not have a change in appearance. Therefore, it is necessary to check each LED with a multimeter or a pointer tester, included in the resistance measurement mode.

There are LED lamps, in which standard LEDs are installed in appearance, in the case of which two crystals connected in series are mounted at once. For example, lamps of the ASD LED-A60 series. For continuity of such LEDs, it is necessary to apply a voltage of more than 6 V to its terminals, and any multimeter outputs no more than 4 V. Therefore, such LEDs can be checked only by applying a voltage of more than 6 (recommended 9-12) V to them from a power source through a 1 kΩ resistor ...

The LED is checked, like a regular diode, in one direction the resistance should be equal to tens of megohms, and if you swap the probes (this changes the polarity of the voltage supply to the LED), then small, while the LED may glow dimly.

When checking and replacing LEDs, the lamp must be fixed. You can use a suitable sized round jar for this.

It is possible to check the health of the LED without an additional constant current source. But this verification method is possible if the light bulb driver is working properly. To do this, it is necessary to apply a supply voltage to the base of the LED light bulb and the terminals of each LED must be sequentially short-circuited with a jumper from a wire or, for example, with a jaw of a metal tweezers.

If suddenly all the LEDs light up, it means that the shorted one is definitely faulty. This method is suitable if only one of the LEDs in the circuit is faulty. With this method of verification, it must be taken into account that if the driver does not provide galvanic isolation from the mains, as, for example, in the above diagrams, then touching the LED solders with your hand is unsafe.

If one or even several LEDs turned out to be faulty and there is nothing to replace them with, then you can simply short-circuit the contact pads to which the LEDs were soldered. The light bulb will work with the same success, only the luminous flux will decrease slightly.

Other malfunctions of LED lamps

If the check of the LEDs showed their serviceability, then the reason for the inoperability of the light bulb is in the driver or in the soldering points of the current-carrying conductors.

For example, a cold soldering conductor was found in this light bulb that supplies power to the printed circuit board. The soot produced by poor soldering even settled on the conductive paths of the printed circuit board. The soot was easily removed by wiping with a cloth soaked in alcohol. The wire was soldered, stripped, tinned and re-soldered into the board. We were lucky with the repair of this light bulb.

Of ten failed bulbs, only one had a faulty driver, a diode bridge collapsed. The repair of the driver consisted in replacing the diode bridge with four IN4007 diodes, designed for a reverse voltage of 1000 V and a current of 1 A.

Soldering SMD LEDs

To replace a faulty LED, it must be evaporated without damaging the printed conductors. You also need to remove the replacement LED from the donor board without damage.

It is almost impossible to solder SMD LEDs with a simple soldering iron without damaging their case. But if you use a special tip for a soldering iron or put on a nozzle made of copper wire on a standard tip, then the problem is easily solved.

The LEDs are polarized and must be correctly installed on the PCB when replacing. Typically, printed conductors follow the shape of the LED leads. Therefore, you can only make a mistake with carelessness. To seal the LED, it is enough to install it on the printed circuit board and warm it up with a 10-15 W soldering iron with its ends with contact pads.

If the LED is burnt to charcoal, and the printed circuit board underneath is charred, then before installing a new LED, it is imperative to clean this place of the printed circuit board from burning, since it is a current conductor. When cleaning, you may find that the solder pads for the LED are burnt or peeled off.

In this case, the LED can be installed by soldering it to adjacent LEDs if the printed paths lead to them. To do this, you can take a piece of thin wire, bend it in half or three, depending on the distance between the LEDs, tin and solder to them.

Repair of LED lamp series "LL-CORN" (corn lamp)
E27 4.6W 36x5050SMD

The device of the lamp, which is popularly called the corn lamp, shown in the photo below is different from the lamp described above, therefore the repair technology is different.

The design of lamps on LED SMD of this type is very convenient for repair, since there is access for the continuity of the LEDs and their replacement without disassembling the lamp body. True, I disassembled the light bulb anyway for interest, in order to study its structure.

Checking the LEDs of the LED corn lamp does not differ from the technology described above, but it must be taken into account that three LEDs are located in the SMD5050 LED case, usually connected in parallel (three dark dots of crystals are visible on the yellow circle), and all three should light up during the check.

A defective LED can be replaced with a new one or short-circuited with a jumper. This will not affect the reliability of the lamp, only imperceptibly to the eye, the luminous flux will decrease slightly.

The driver of this lamp is assembled according to the simplest scheme, without an isolation transformer, therefore, touching the LED leads while the lamp is on is unacceptable. Lamps of this design must not be installed in luminaires that can be accessed by children.

If all the LEDs are in good working order, then the driver is faulty, and in order to get to it, the lamp will have to be disassembled.

To do this, you need to remove the bezel from the side opposite to the base. With a small screwdriver or a knife blade, you need to try in a circle to find weakness where the bezel is least glued. If the bezel gives in, then working with a tool, like a lever, the bezel will easily move away around the entire perimeter.

The driver was assembled according to the electrical circuit, like that of the MR-16 lamp, only C1 was 1 µF, and C2 was 4.7 µF. Due to the fact that the wires leading from the driver to the lamp base were long, the driver was easily pulled out of the lamp housing. After studying its circuit, the driver was inserted back into the case, and the bezel was glued in place with transparent glue "Moment". The failed LED has been replaced with a good one.

Repair of LED lamp "LL-CORN" (corn lamp)
E27 12W 80x5050SMD

When repairing a more powerful lamp, 12 W, the same design of failed LEDs was not found and in order to get to the drivers, I had to open the lamp using the technology described above.

This lamp gave me a surprise. The wires leading from the driver to the base turned out to be short, and it was impossible to remove the driver from the lamp housing for repair. I had to remove the base.

The lamp base was made of aluminum, nibbled around the circumference and held firmly. I had to drill out the attachment points with a 1.5 mm drill. After that, the base, which had been pushed with a knife, was easily removed.

But you can do without drilling the base if you pry and slightly bend its upper edge with the edge of a knife around the circumference. Beforehand, a mark should be made on the plinth and the casing so that the plinth can be conveniently installed in place. To securely fix the base after repairing the lamp, it will be enough to put it on the lamp body in such a way that the punched points on the base fall into the old places. Then push through these points with a sharp object.

Two wires were connected to the thread with a clamp, and the other two were pressed into the central contact of the base. I had to eat these wires.

As expected, the drivers were two identical, supplying 43 diodes each. They were covered with a heat-shrinkable tube and taped together. In order for the driver to fit back into the tube, I usually cut it neatly along the PCB on the side where the parts are to be installed.

After repair, the driver is wrapped in a tube, which is fixed with a plastic tie or wrapped in several turns of thread.

In the electrical circuit of the driver of this lamp, protection elements are already installed, C1 for protection against impulse surges and R2, R3 for protection against current surges. When checking the elements, resistors R2 were immediately found on both drivers in the open circuit. It looks like an overvoltage has been applied to the LED lamp. After replacing the resistors, there was no 10 Ohm at hand, and I set it to 5.1 Ohm, the lamp worked.

Repair of LED lamp series "LLB" LR-EW5N-5

The appearance of this type of light bulb inspires confidence. Aluminum body, high quality workmanship, beautiful design.

The design of the light bulb is such that disassembling it without significant physical effort is impossible. Since the repair of any LED lamp begins with checking the health of the LEDs, the first thing that had to be done was to remove the plastic protective glass.

The glass was fixed without glue on a groove made in the radiator with a collar inside it. To remove the glass, you need to use the end of a screwdriver that will pass between the fins of the radiator, lean on the end of the radiator and lift the glass up like a lever.

Checking the LEDs with a tester showed their serviceability, therefore, the driver is faulty, and you need to get to it. The aluminum board was secured with four screws that I unscrewed.

But contrary to expectations, behind the board was the heatsink plane, smeared with heat-conducting paste. The board had to be returned to its place and continue to disassemble the lamp from the side of the base.

Due to the fact that the plastic part, to which the radiator was attached, held very tightly, I decided to go the proven way, remove the base and remove the driver through the opened hole for repair. I drilled out the punching places, but the base did not come off. It turned out that he still held on to the plastic due to the threaded connection.

I had to separate the plastic adapter from the radiator. He held on, just like the protective glass. To do this, a hacksaw was made for metal at the junction of the plastic with the radiator and by turning a wide-blade screwdriver, the parts were separated from each other.

After unsoldering the leads from the LED printed circuit board, the driver became available for repair. The driver circuit turned out to be more complex than the previous bulbs, with an isolation transformer and a microcircuit. One of the 400 V 4.7 µF electrolytic capacitors was swollen. I had to replace him.

Checking all the semiconductor elements revealed a faulty D4 Schottky diode (pictured below left). On the board there was a Schottky diode SS110, replaced by the existing analogue 10 BQ100 (100 V, 1 A). The forward resistance of Schottky diodes is half that of ordinary diodes. The LED light is on. The second light bulb had the same malfunction.

Repair of LED lamp series "LLB" LR-EW5N-3

This LED lamp is very similar in appearance to the "LLB" LR-EW5N-5, but the design is slightly different.

If you look closely, you can see that at the junction between the aluminum radiator and the spherical glass, unlike the LR-EW5N-5, there is a ring in which the glass is fixed. To remove the protective glass, it is enough to pick it up with a small screwdriver at the junction with the ring.

The aluminum PCB has three nine super-bright crystal LEDs. The board is screwed to the heatsink with three screws. Checking the LEDs showed their serviceability. Hence, the driver needs to be repaired. Having experience in repairing a similar LED lamp "LLB" LR-EW5N-5, I did not unscrew the screws, but unsoldered the lead wires coming from the driver and continued to disassemble the lamp from the base side.

The plastic connecting ring of the base / plinth with the radiator was removed with great difficulty. At the same time, part of it broke off. As it turned out, it was screwed to the radiator with three self-tapping screws. The driver was easily removed from the lamp housing.

The self-tapping screws screwing the plastic ring of the base cover the driver, and it is difficult to see them, but they are on the same axis with the thread to which the transition part of the radiator is screwed. Therefore, you can reach them with a thin Phillips screwdriver.

The driver was assembled according to the transformer circuit. Checking all the elements, except for the microcircuit, did not reveal those that failed. Consequently, the microcircuit is faulty, I did not even find a mention of its type on the Internet. The LED light bulb could not be repaired, it will come in handy for spare parts. But I studied her device.

Repair of LED lamp series "LL" GU10-3W

At first glance, it turned out to be impossible to disassemble a burnt-out GU10-3W LED bulb with protective glass. An attempt to remove the glass led to its chipping. When applied with great effort, the glass cracked.

By the way, in the marking of the lamp, the letter G means that the lamp has a pin base, the letter U, that the lamp belongs to the class of energy-saving bulbs, and the number 10 is the distance between the pins in millimeters.

LED bulbs with GU10 base have special pins and are installed in a socket with a twist. Thanks to the expanding pins, the LED lamp is pinched in the holder and is securely held even when shaken.

In order to disassemble this LED light bulb, we had to drill a hole with a diameter of 2.5 mm in its aluminum case at the level of the surface of the printed circuit board. The place of drilling must be chosen in such a way that the drill does not damage the LED when exiting. If you do not have a drill at hand, then the hole can be made with a thick awl.

Next, a small screwdriver is threaded into the hole and, acting like a lever, the glass is lifted. I removed glass from two bulbs without any problems. If the test of the LEDs with a tester showed their serviceability, then the printed circuit board is removed.

After separating the board from the lamp body, it immediately became obvious that the current-limiting resistors had burned out both in one and in the other lamp. The calculator determined their nominal value by the bands, 160 ohms. Since the resistors burned out in LED bulbs of different batches, it is obvious that their power, judging by the size of 0.25 W, does not correspond to the power released when the driver is operating at the maximum ambient temperature.

The driver PCB was solidly sealed with silicone, and I didn’t detach it from the LED board. I cut off the leads of the burned-out resistors at the base and soldered more powerful resistors to them, which were at hand. In one lamp, a 150 Ohm resistor with a power of 1 W was soldered, in the second two parallel 320 Ohm with a power of 0.5 W.

In order to prevent accidental touching of the resistor terminal, to which the mains voltage with the metal lamp housing is suitable, it was insulated with a drop of hot melt glue. It is waterproof, excellent insulator. I often use it for sealing, insulating and securing electrical wires and other parts.

Hot melt glue is available in the form of rods with a diameter of 7, 12, 15 and 24 mm in different colors, from transparent to black. It melts, depending on the brand, at a temperature of 80-150 °, which allows it to be melted using an electric soldering iron. It is enough to cut off a piece of the rod, place it in the right place and heat it up. The hot melt glue will acquire the consistency of May honey. After cooling, it becomes solid again. When reheated, it becomes liquid again.

After replacing the resistors, the performance of both bulbs was restored. All that remains is to fix the PCB and protective glass in the lamp housing.

When repairing LED bulbs, I used "Montage" liquid nails to fix PCBs and plastic parts in place. Odorless glue, adheres well to the surfaces of any materials, after drying it remains plastic, has sufficient heat resistance.

It is enough to take a small amount of glue on the end of a screwdriver and apply it to the contact points of the parts. After 15 minutes, the glue will already hold.

When gluing the printed circuit board, in order not to wait, holding the board in place, since the wires pushed it out, I fixed the board additionally at several points with hot glue.

The LED lamp started flashing like a strobe

I had to repair a couple of LED lamps with drivers assembled on a microcircuit, the malfunction of which was the blinking of light with a frequency of about one hertz, like in a stroboscope.

One copy of the LED lamp started blinking immediately after switching on for the first few seconds and then the lamp began to shine normally. Over time, the duration of the lamp blinking after turning on began to increase, and the lamp began to blink continuously. The second copy of the LED lamp began to flash continuously suddenly.

After disassembling the lamps, it turned out that the electrolytic capacitors installed immediately after the rectifier bridges in the drivers were out of order. It was easy to identify the fault as the capacitor housings were swollen. But even if in appearance the capacitor looks without external defects, then all the same, the repair of an LED light bulb with a stroboscopic effect must begin with its replacement.

After replacing the electrolytic capacitors with serviceable ones, the stroboscopic effect disappeared and the lamps began to shine normally.

Online calculators for determining the value of resistors
by color coding

When repairing LED lamps, it becomes necessary to determine the value of the resistor. According to the standard, marking of modern resistors is made by applying colored rings to their cases. 4 colored rings are applied to simple resistors, and 5 to high precision resistors.

It is unpleasant to watch how the incandescent lamp burned out. However, this familiar problem can be solved by simply replacing it with a new light bulb with minimal impact on the family budget. It is much worse if an LED lamp unexpectedly burns out, the price of which is an order of magnitude higher. Similar problems arise among motorists who want to experience the power of the LED stream on the track. Why does the declared runtime with four zeros for some LED (light-emitting diode) lamps remain only on the label? What do you need to know to navigate among the many new LED products? In search of answers, we will consider the reasons for the failure of light bulbs and provide several solutions.

Driver relevance

A stabilized rated current (nameplate) must flow through any LED, regardless of the application. Only in this case, the glow will be even, and the operating time of the crystal will be able to cross the border of 10 thousand hours. Regardless of the shape, size and number of LEDs, all LED lamps can be divided into two main categories according to the way they are controlled:

• based on a driver with a pulsed load current shaper;
• based on a ballast voltage source.

A driver with a pulse transformer and a current converter is the only correct one technical solution for power supply of LED lamps, which are produced industrially.

To appreciate the importance of a current stabilizer, consider its principle of operation with a short example. In ceiling chandeliers with LED lighting, as a rule, a current stabilizer unit is installed. Its output voltage varies over a wide range, and the output current value will remain constant even with one LED in the load. In such a chandelier, a burned-out LED can simply be short-circuited. More powerful current drivers operate on approximately the same principle.

Considering that the production of LED bulbs with a pulsed current driver is not economically justified, Chinese entrepreneurs decided to simplify its design. Instead of a driver, a ballast power supply without a current stabilization function is installed in the LED lamp housing. Its output voltage is calculated based on the number of SMD LEDs inside the case. As a result of voltage drops in the mains, the luminescence power of the lamp changes. And frequent phase jumps up to 240 V lead to the fact that LED lamps burn out.

Low quality products

Most of the LED bulbs from Chinese brands burn out due to poor build quality. Several unpleasant surprises can be hidden under the stylish appearance of the product:

• a cheap electrolytic capacitor that gradually loses its capacity when operating in a high-temperature environment;
• lack of high-quality heat sink;
• lack of a good driver;
• "Cold soldering" of contact pads, etc.

If you look inside the body of a burned-out LED lamp, you will find that the thermal grease is only partially applied to the aluminum substrate. As a result, heat dissipation from the board to the radiator is uneven, which leads to overheating of the emitting SMD element, which is in the worst temperature regime. Smart Chinese engineers calculate the ballast power supply so that the output voltage on it is slightly higher than the nominal. The initial brightness of such a product impresses the buyer, which means that the commercial goal has been achieved. In the best case, after several months of operation, the luminous flux will decrease by 30%, in the worst case, the lamp will burn out.

The listed facts indicate a deliberate deterioration in the technical characteristics of the product by the manufacturer. After all, if everyone switches to high-quality LED lighting, then who will buy the lamps?

Why do LED lamps in an apartment burn out?

If the quality of the light bulb is not in doubt, then its burnout may be caused by a problem in the wiring. Loose contact in the socket or in the junction box will cause power surges and breakdown.
In cheap LED bulbs, insufficient heat dissipation from the light-emitting crystals forces the LEDs to work on the verge of overheating. Installation of such lamps in the kitchen, where the air temperature under the ceiling during the operation of a gas or electric oven exceeds 30 ° C, also contributes to the accelerated degradation of the crystal with all the ensuing consequences.

The organization of decorative lighting from LED strips also needs to be given due attention. If the tape of the SMD 5050 type is not glued to a special aluminum profile, then soon it will be possible to observe the extinction of individual segments.

Why do LED bulbs in a car burn out?

By replacing the usual halogen bulbs with LED bulbs, the car owner hopes to get the most out of them. However, a lack of knowledge about advertised light sources leads to their combustion.

Often a lack of experience is buying car LED bulbs without proper drivers. The role of the current limiter is played by a powerful resistor. Everything turns out to be simple, but not reliable. With such a circuitry, an increase in the voltage of the on-board network from 12 V to 14 V, which is detrimental to LED bulbs. A proportional increase in current leads to flickering, partial extinction, and then burnout of the lamp. Blaming low-quality goods for everything, you can continue to put lamps of dubious firms and "step on the same rake."

The second common reason is the small wholesale order of LED lamps of the "no name" type via the Internet. Having saved one hundred rubles, the buyer runs the risk of getting several defective copies or products with a non-standard base, manual revision of which will worsen the technical data.

And also the design features of some headlights do not allow to additionally place LEDs of dimensions and turns in them. Such modernization leads to their overheating due to the heat from the native headlamps.

As a sedative, owners of burned-out LED lamps can be advised to have them repaired. In comparison with incandescent bulbs and halogens, this is a big plus. The main thing is to correctly identify the burned out element during the repair and eliminate the cause of the product failure.

Read the same

With a variety on the shelves of the country, they remain out of competition due to their economy and durability. However, a high-quality product is not always purchased, because in a store you cannot disassemble the goods for inspection. And in this case, it is not a fact that everyone will determine from what parts it is assembled. burn out, and it becomes expensive to buy new ones. The solution is to repair LED lamps with your own hands. This work is within the power of even a novice home craftsman, and the details are inexpensive. Today we will figure out how to check in what cases the product is being repaired and how to do it.

It is known that LEDs cannot operate directly from a 220 V network. For this they need optional equipment, which, more often than not, fails. We will talk about him today. Consider a circuit without which the work of the lighting device is impossible. Along the way, we will conduct an educational program for those who do not understand anything in electronics.

driver gauss 12w

The 220V LED lamp driver circuit consists of:

• diode bridge;
• resistances;
• resistors.

The diode bridge serves to rectify the current (converting it from alternating to direct current). On the graph, this looks like a cut-off of a half-wave of a sine wave. Resistances limit current, and capacitors store energy by increasing the frequency. Consider the principle of operation on the circuit of a 220 V LED lamp.

The principle of operation of the driver in a lamp on LEDs

View on the diagram	Operating procedure
	A voltage of 220 V is supplied to the driver and passes through a smoothing capacitor and a current limiting resistor. This is necessary in order to secure the diode bridge.
	The voltage is applied to a diode bridge consisting of four multidirectional diodes that cut off the half-wave of the sinusoid. The output current is constant.
	Now, by means of a resistance and a capacitor, the current is again limited and set to the desired frequency.
	The voltage with the required parameters is fed to the equally directional light diodes, which also serve as a current limitation. Those. when one of them burns out, the voltage rises, which leads to the failure of the capacitor if it is not powerful enough. This happens in Chinese products. High-quality devices are protected from this.

Having understood the principle of operation and the driver circuit, the decision on how to fix a 220V LED lamp will no longer seem difficult. If we talk about quality, then you should not expect trouble from them. They work for the entire prescribed period and do not fade, although there are "diseases" to which they are also susceptible. Let's talk about how to deal with them.

Causes of failure of LED lighting devices

To make it easier to understand the reasons, we summarize all the data in one common table.

Good to know! Repair of LED fixtures is impossible to carry out indefinitely. It is much easier to eliminate negative factors affecting durability and not to purchase cheap products. Savings today will cost you tomorrow. As economist Adam Smith said, "I'm not rich enough to buy cheap things."

DIY 220 V LED lamp repair: the nuances of the work

Before you repair an LED lamp with your own hands, pay attention to some details that require less labor. Checking the cartridge and the voltage in it is the first thing to do.

Important! Repair of LED lamps requires a multimeter - without it, it will not be possible to ring the driver elements. A soldering station is also required.

household multimeters

A soldering station is required for the repair of LED chandeliers and lighting fixtures. After all, overheating of their elements leads to failure. The heating temperature during soldering should be no higher than 2600, while the soldering iron heats up more. But there is a way out. We use a piece of copper core with a cross section of 4 mm, which is wound around the tip of the soldering iron with a tight spiral. The more you lengthen the sting, the lower its temperature. Convenient if the multimeter has a thermometer function. In this case, it can be adjusted more precisely.

Soldering Station

But before you repair LED spotlights, chandeliers or lamps, you need to determine the cause of the failure.

How to disassemble an LED light bulb

One of the problems that a novice home craftsman faces is how to disassemble an LED light bulb. To do this, you need an awl, solvent and a syringe with a needle. The diffuser of the LED lamp is glued to the body with a sealant that must be removed. Passing carefully along the edge of the diffuser with an awl, inject the solvent with a syringe. After 2 ÷ 3 minutes, lightly twisting, the diffuser is removed.

Some lighting fixtures are made without gluing with a sealant. In this case, it is enough to turn the diffuser and remove it from the housing.

We identify the cause of the failure of the LED light bulb

Having disassembled the lighting fixture, pay attention to the LED elements. Burned is often identified visually: there are burn marks or black dots on it. Then we change the faulty part and check the functionality. We will describe the replacement in detail in the step-by-step instructions.

If the LED elements are in order, go to the driver. To check the performance of its parts, you need to solder them from the printed circuit board. The value of the resistors (resistances) is indicated on the board, and the parameters of the capacitor are indicated on the case. When dialing with a multimeter in the appropriate modes, there should be no deviations. However, often failed capacitors are determined visually - they swell or burst. The solution is to replace it with a suitable one in terms of technical parameters.

Replacing capacitors and resistances, unlike LEDs, is often performed with a conventional soldering iron. In this case, you should be careful not to overheat the nearest contacts and elements.

Replacing Light Bulb LEDs: How Difficult It Is

If you have a soldering station or a hair dryer, this job is simple. It is more difficult to work with a soldering iron, but it is also possible.

Good to know! If there are no working LED elements at hand, you can install a jumper instead of the burnt one. Such a lamp will not work for a long time, but it will be possible to win some time. However, such repairs are made only if the number of elements is more than six. Otherwise, the day is the maximum work of the repair product.

Modern lamps run on SMD LED-elements, which can be evaporated from led strip... But it is worth choosing those that are suitable for technical characteristics. If there are none, it is better to change everything.

Related article:

For the correct choice of LED devices, you need to know not only general ones. Information about modern models, electrical circuits of working devices will come in handy. In this article, you will find answers to these and other practical questions.

Repair of the LED lamp driver in the presence of the electrical circuit of the device

If the driver consists of smaller SMD components, use a copper wire soldering iron on the tip. A visual inspection revealed a burnt element - we solder it and select the one that matches the marking. No visible damage is more difficult. We'll have to solder all the details and ring them separately. Having found the burned-out one, we change it to a workable one. It is convenient to use tweezers for this.

Useful advice! Do not remove all elements from the PCB at the same time. They are similar in appearance, you can later confuse the location. It is better to solder the elements one at a time and, after checking, mount them in place.

How to check and replace the power supply of LED lights

When installing lighting in rooms with high humidity (or), stabilizing ones are used, which lower the voltage to a safe one (12 or 24 volts). The stabilizer can fail for several reasons. The main ones are excessive load (power consumption of the luminaires) or the wrong choice of the degree of protection of the unit. Such devices are repaired in specialized services. At home, this is unrealistic without the availability of equipment and knowledge in the field of radio electronics. In this case, the power supply unit will have to be replaced.

LED power supply

Very important! All work on replacing the stabilizing LED power supply is carried out with the voltage removed. Do not rely on the switch - it may be incorrectly wired. The voltage is disconnected in the distribution board of the apartment. Remember that touching live parts with your hand is life-threatening.

You need to pay attention to specifications devices - the power must exceed the parameters of the lamps that are powered from it. Having disconnected the failed unit, we connect a new one according to the diagram. It can be found in the technical documentation of the device. This is not difficult - all wires are color-coded, and the contacts are letter designation.

Plays the role and degree of protection of the device (IP). For the bathroom, the device must be marked at least IP45.

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