Resistor for LED lamp 220. Do-it-yourself LED lamp repair: causes of breakdowns and how to fix it

Device led lamp at 220V is much more difficult than that of a similar incandescent lamp. Trying to keep the habit pear-shaped, the engineers had to work hard. And, as it turned out, not in vain! New lighting devices practically do not heat up, consume a small amount of electricity and are much less fragile. But what is special about the LED lamp and what is the complexity of its circuit? Let's figure it out.

Structural scheme

Structurally, the 220V LED lamp circuit consists of three main parts: the housing, the electronic part and the cooling system. The mains voltage through the base is supplied to the driver, where it is converted into a DC signal, which is necessary for the LEDs to glow. The light from the emitting diodes has a wide dispersion angle and therefore does not require the installation of additional lenses. Enough to get by with a diffuser. During operation, driver parts and LEDs heat up. Therefore, in the design of the lamp, heat dissipation must be thought out. The housing part of the LED lamp includes a base, a plastic shell, inside which the driver is located, and a translucent cover in the form of a hemisphere, which is also a light diffuser. In expensive models of lamps, most of the body is occupied by a finned radiator made of aluminum or special heat-conducting plastic. In budget-class light bulbs, the radiator is either completely absent or located inside, and holes are made around the circumference of the body. Cheap Chinese products with a power of up to 7 W have a solid body, without any heat dissipation.

In branded 220V LED lamps, the printed circuit board with SMD LEDs is attached to the heatsink through thermal paste for efficient heat dissipation. In cheap Chinese models, this board is either simply inserted into the grooves of the case, or attached with screws to a metal plate to cool the crystals. The efficiency of such cooling is extremely low, since the plate has a small area, and Chinese manufacturers, as a rule, forget to apply thermal paste.
The output of radiation occurs through a diffuser, usually made of matte plastic. And in cheap 220V LED lamps, such a case still reliably hides the shortcomings of the Chinese assembly from the prying eyes of the consumer. The diffuser is attached to the base either with a sealant or a threaded connection.

Wiring diagram

Regarding the electrical part, there are also many differences between 220V LED lamps of different price categories. This can be seen immediately after dismantling the diffuser. It is enough to consider the quality of soldering SMD elements and connecting wires.

Inexpensive Chinese lamp for 220V

In light bulbs costing $ 2-3, there is no symmetry on the board with LEDs, which indicates manual soldering, and the wires are selected with the smallest possible cross section. Instead of a reliable driver, they contain simple circuit transformerless power supply with capacitors and a rectifier. The mains voltage is first reduced by a non-polar metal film capacitor, rectified, and then smoothed and raised to the desired level. The load current is limited by a conventional SMD resistor, which is located on printed circuit board with LEDs.
When diagnosing and repairing LED lamps of this type, it is important to observe safety precautions, because. all elements of the electrical circuit are potentially under high voltage. Touching a live part of a circuit with a finger can inadvertently cause an electric shock, and a slipped multimeter probe can short-circuit the wires with unpleasant consequences.

Branded LED lamp

Branded LED products are distinguished not only by their pleasant appearance, but also by their quality. element base. The driver itself has a more complex device and is often assembled in one of two ways. The first one provides for the presence of a pulse transformer, a pulse voltage converter with subsequent stabilization of the load current.

In the second case, a transformer is dispensed with, and the main functional load falls on a special microcircuit - the heart of the driver. Its versatility lies in the fact that it stabilizes the input voltage, maintains the output current with a given frequency (PFM) or pulse width (PWM), allows dimming, and has a negative feedback system. As an example, for example, CPC9909 can be mentioned.
LEDs in a 220V lamp with a current driver are reliably protected from voltage surges and interference in the network, the current through them corresponds to the nominal passport value, and the radiator provides high-quality heat dissipation. Such light bulbs will last much longer than cheap Chinese counterparts, thereby proving the advantage of LEDs in practice.

How to disassemble the LED lamp MR-16

To identify the cause of the breakdown, it is necessary to disassemble the lamp housing. This is done without much effort.

As you can see in the photo, a ribbed surface is visible on the case. It is made for better heat dissipation. We insert a screwdriver into one of the ribs and try to lift the glass.

Happened. You can see the printed circuit board, it is glued to the case. Prying it with a screwdriver, it separates.

Repair of LED bulbs MR-16

Among the first, the lamp was disassembled, inside which the LED burned out. The printed circuit board, which is made of fiberglass, burned through.

This lamp is suitable as a "donor", the necessary spare parts for the repair of other lamps will be taken from it. On the remaining 9 lamps, the LEDs also burned out. Since the driver is intact, it is the LEDs that are the cause of the breakdown.

Electrical diagram of the LED lamp MR-16

To reduce the repair time of lamps, it is necessary to create its electrical circuit. She is pretty simple.

Attention! The circuit is connected to the network phase in a galvanic way. It is prohibited to use it to power any devices.

How does the scheme work? A voltage of 220 V is applied to the diode bridge VD1-VD4 through the capacitor C1. Then it goes to the LEDs HL1-HL27, which are connected in series in the circuit. The number of LEDs can be about 80 pieces. Capacitor C2 (the larger the capacitance, the better) is a rectified voltage ripple smoother. It eliminates the flickering of light having a frequency of 100 Hz. To discharge C1, R1 was installed. This is necessary in order to avoid electric shock when replacing the lamp. C2 is protected from breakdown by R2 in case an open circuit occurs. R1, R2 as such do not accept work in the circuit.

C1- red, C2- black, diode bridge - case with four legs.

Classic driver circuit for LED lamps up to 5 W

The electrical circuit of the lamps has no protection elements. You will need a 100-200 ohm resistor, preferably two. One will be installed in the connection circuit, the second will serve as protection against current surges.

Above is a circuit with protective resistors. R3 protects the LEDs and C2 the capacitor, R2 in turn is the diode bridge. This driver is perfect for lamps whose power is less than 5 watts. It will easily power a lamp having 80 SMD3528 type LEDs. If you need to reduce or increase the current, manipulate the capacitor C1. To eliminate flicker, increase the capacitance C2.

The efficiency of such a driver is less than 50%. For example, an MR-16-2835-F27 lamp requires a 6.1 kΩ resistor with a power of 4 watts. Then the driver will consume power in excess of the power consumption of the LEDs. Due to the large release of thermal energy, it will not work to place it in a small lamp body. In this case, you can separately make a case for this driver.

It should be remembered that the efficiency of the lamp directly depends on the number of LEDs.

Finding faulty LEDs

After the protective glass has been removed, you can inspect the LEDs. If the slightest black spot is found on the surface of the LED, it is out of order. Inspect the soldering points, inspect the quality of the conclusions. In one of the lamps, 4 badly soldered LEDs were found

LEDs with black dots were marked with a cross. When viewed from the outside, the LEDs can be intact. Therefore, you need to call them with a tester. To check, you need a voltage of a little more than 3 V. A battery, a battery, a power supply will do. Behind the power supply, a current-limiting resistor with a nominal value of 1 kΩ is connected in series.

Touch the probes to the LED. In one direction, the resistance should be small (the LED can glow), in the other, it should be equal to tens of megaohms.

During the test, it is necessary to fix the lamp. A bank can help.

You can check the LED without special devices if the device driver is intact. Voltage is applied to the lamp base, the leads of the LEDs are shorted with tweezers or a piece of wire.

If you can see the glow of all LEDs, the shorted one is faulty. But this method is suitable if 1 LED is out of order in the circuit.

If several LEDs are broken in the circuit, the lamp will be on. Only its luminous flux will decrease. Just short the pads where the LEDs were soldered to.

Other malfunctions of LED lamps

If during the test it turned out that the LEDs are working, then the problem is in the driver or the place of soldering.

In this lamp, a cold soldered conductor was found. Soot, which appeared due to poor soldering, settled on the tracks of the board. To remove the soot, a cloth soaked in alcohol was needed. The wire was soldered, tinned and soldered. This lamp worked.

Of all the lamps, one had a driver failure. The diode bridge was replaced by 4 "IN4007" diodes, which are rated for 1 A current and 1000 V reverse voltage.

Soldering SMD LEDs

To replace a faulty LED, it is necessary to desolder it without damaging the printed conductors. This can be done with difficulty with an ordinary soldering iron; it is better to put a tip made of copper wire on the soldering iron.

When soldering the LED, it is necessary to monitor the polarity. Install the LED in the soldering place, take a 10-15 W soldering iron and warm up its ends.

If the LED is burnt, and the board is charred, this place should be cleaned. Because it is a conductor. If the site is stratified, solder the LED mono to the "neighbors". This is done if the paths lead exactly to them. Just take a piece of wire, fold two or three times and solder.

Analysis of the causes of failure of LED lamps MR-16-2835-F27

According to the table, we can conclude that lamp failures often occur due to the failure of LEDs. The reason for this is the lack of protection in the circuit. Although there is a place for a varistor on the board.

LL-CORN series LED lamp repair (corn lamp) E27 4.6W 36x5050SMD

The technology for repairing the "corn" lamp is different from the repair of the lamp shown above.

Repair of such a lamp is simple, since the LEDs are located on the body. And it doesn't take any extra steps to make a call. This lamp was dismantled purely out of curiosity.

The technique for checking "corn" does not differ from the one described above. Only in the body of these lamps 3 LEDs are installed. When dialing, all 3 should light up.

If one of the LEDs is broken, short it out or solder in a new one. This will not affect the lamp life. The lamp driver does not have a decoupling transformer. Therefore, any touch to the LED tracks is unacceptable.

If the LEDs are intact, the problem is in the driver. In order to inspect it, it is necessary to disassemble the case.

To get to the driver, you need to remove the bezel. Pry it with a screwdriver in the very weak point, it should peel off.

The driver has the same circuit as our first lamp with the difference that C1-1µF, C2-4.7µF. The wires are long so the driver pulls out effortlessly. After work on replacing the LED, the bezel was planted on Moment glue.

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

Repair of a 12 W lamp is done in the same way. No burnt LEDs were found on the case, so I had to open the case to inspect the driver.

There is a problem with this lamp. The driver wires were too short, had to remove the base.

The plinth is made of aluminium. It was attached to the body with the help of a punch. Therefore, it was necessary to drill out the attachment points with a drill, the diameter of which is 1.5 mm. Next, the plinth was hooked with a knife and removed. The wires inside had to be cut.

Inside were 2 identical drivers, each of which powered 43 diodes.

The driver is shrouded in heat-shrinkable tubing, which had to be cut.

After troubleshooting, the same tube is placed on the driver and crimped with a plastic tie.

The driver circuit implies protection. C1 protects against surges, R2, R3 from surges. During the verification work, R2 breaks were noticed. Most likely, a voltage exceeding the norm was applied to the lamp. There was no 10 ohm resistor, so a 5.1 ohm resistor was soldered in. The lamp lit up. Next, it was necessary to connect the driver to the base.

First of all, short wires were replaced with longer ones. The drivers were connected by supply voltage. To attach the wires to the threaded part of the base, it is necessary to clamp them between the plastic housing and the base.

And how to connect to the central contact? Aluminum is not solderable, so the wire was soldered to a brass plate, in which a hole was drilled under M 2.5. A similar hole was drilled in the contact. All this was screwed together. Next, the base was put on and fastened to the lamp body by pinning. The lamp was working.

Repair LED lamp series "LLB" E27 6 W 128-1

The design of the lamp is ideal for repairs. The case is easily disassembled.

Hold the base with one hand, and turn the protective cover counterclockwise with the other.

Under the case there are five rectangular boards on which the LEDs are soldered. The rectangle is soldered to a round board on which the driver circuit is located.

To access the LED pins, you need to remove one of the covers. To facilitate the work, it is better to remove the board located at the driver voltage supply points. The photo shows that this wall is parallel to the capacitor case and is at a maximum distance from it.

To remove the board, it is necessary to warm up the soldering points with a soldering iron. Then, to remove it, we warm up the soldering on the round board and it is disconnected.

Access to check breakdowns is open. The driver is made according to a simple scheme. Checking it out rectifier diodes, as well as all the LEDs (there are 128 of them in this lamp) did not show a problem.

When I examined the soldering points, I found that they were missing at some points. These places were soldered, in addition, I connected the printed tracks of the boards in the corners.

When you look at the light, these paths are clearly visible and you can easily determine which path is which.

Before assembling the lamp, it was necessary to check it. To do this, a jumper was installed on the board, the soldered part of the lamp was connected to the power source with two temporary wires.

The lamp lit up. It remains to solder the board to its original place and assemble the lamp.

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

On the appearance The lamp is well made. The body is aluminum and the design is beautiful.

The lamp is assembled securely. Therefore, in order to disassemble it, you need to remove the protective glass. To do this, stick the end of the screwdriver between the radiator. The glass is fixed here without glue, with a collar. You need to lean with a screwdriver on the end of the radiator and lift the glass up, using the screwdriver as a lever.

The tester did not show a breakdown of the LEDs. So it's all about the driver. To get to it, you need to unscrew 4 screws.

But I failed. Behind the board was a radiator plane. It is lubricated with a paste that conducts heat. I had to collect everything that I untwisted. I decided to disassemble the lamp from the side of the base.

In order to remove the base, I had to drill out the punching points. But he didn't film. As it turned out, it was fastened with plastic threaded connection.

The radiator had to be separated from the plastic adapter. To do this, I washed down with a hacksaw in the place where the plastic was attached to the radiator. Further, by turning the screwdriver, the parts separated one from the other.

The leads were soldered from the LED board, which made it possible to work with the driver. Its circuitry was more complex than other drivers. Upon inspection, a swollen 400 V 4.7 µF capacitor was found. He has been replaced.

Schottky diode "D4" type SS110 was damaged. It is at the bottom left of the photo. It has been replaced by the analogue "10 BQ100", having 1 A and 100 V. The light bulb lit up.

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

The lamp is similar to the "LLB" LR-EW5N-5, but its design has been changed.

The protective glass is attached with a ring. If you pick up the junction of the ring and glass, it can be easily removed.

The printed circuit board is made of aluminium. It contains nine crystal LED light emitting diodes quantity of 3 pieces. The board is attached with 3 screws to the heatsink. The test did not reveal any problems with the LEDs. So it's a driver issue. The experience of repairing a similar lamp showed that it is better to immediately unsolder the wires that come from the driver. The disassembly of the lamp was carried out from the side of the base.

The ring connecting the base and the radiator was removed with great effort. At the same time, a piece broke off. And all due to the fact that it was screwed with 3 screws. The driver has been extracted.

Self-tapping screws are located under the driver, you can get to them with a Phillips screwdriver.

This driver is based on a transformer circuit. The check showed the serviceability of all parts, except for the microcircuit. I didn't find any information about her. The lamp was set aside as a donor.

Repair LED lamp series "LLC" E14 3W1 M1

This lamp is similar to an incandescent lamp. The first thing you notice is the wide metal ring.

I started disassembling the lamp. The first step was to remove the cover. As it turned out, he was planted on the base with an elastic compound. After I took it off, I realized that it was in vain.

There was 1 LED in the lamp, the power of which was 3.3 watts. It could be checked from the plinth side.

The lamp was fastened to the body with the help of a "left" thread. You need to rotate the base counterclockwise, if you look at it from the side of the central contact.

The cause of the failure was a wire that fell off the thread on the base. You can’t take aluminum by soldering, so it was necessary to look for an option for attaching the wire.

A piece of 5 cm was soldered to the existing wire for extension. A hole was drilled at the punching point, the diameter of which was 2 mm. A wire was threaded into it and wound around a screw. The screw itself was inserted into the hole and clamped with a nut. This lamp glowed like new.

Repair LED lamp series "LL" GU10-3W

The lamp type "LL" GU10-3W was difficult to disassemble. The glass started to crack the moment I tried to take it out.

What does the marking mean?

G - the presence of a pin base;
U - energy saving lamp;
10 - the size between the pins (measured in mm)

Thanks to the expansion pins, the lamp is firmly held in the socket.

This lamp could be disassembled with a drilled hole. The drilling location was at the level of the printed circuit board. Svelo was chosen with a diameter of 2.5 mm. When drilling, you need to take into account the fact that the drill can damage the LED. If there is no drill, then the hole can be made with an awl.

A screwdriver is inserted into the hole made. Using it as a lever, it is necessary to lift the glass. If no problems are found when checking the LEDs, we remove the printed circuit board.

Burnt 160 ohm resistors were found in both lamps. By size, it was possible to establish that their power is 0.25 watts. It does not correspond to the power that is released during lamp operation.

The board was filled with silicone, I did not disconnect it. I replaced the burnt resistors with more powerful ones. In one lamp, I used a 150 Ohm and 1 W resistor, on the other 2 320 Ohm and 0.5 W soldered in parallel.

To avoid a short circuit, the leads of the resistors were smeared with silicone. It acts as an insulator.

On the market you can find 2 types of silicone: liquid in tubes and solid, having the form of a rod. Rod is good because it can be separated with a soldering iron and applied to the desired surface. After hardening, it becomes strong.

Both lamps were lit. It remains to attach the board and put on the protective glass.

To fix the boards, I use liquid nails "Installation" moment. After drying, this adhesive has plasticity and good heat resistance.

Glue is applied with a screwdriver. After 15 minutes, he will hold our part.

In order not to hold the board until the glue is completely dry, I fix it with silicone at some points. The glass was glued with liquid nails, the lamp became operational.

LED lamps are the most expensive lighting fixtures. But their quality and durability do not always correspond to the parameters indicated on the packaging. It is annoying to throw away a lamp that has not served its due date, having invested in it tangible funds for the budget.

If you have a multimeter and soldering skills, then a faulty LED lamp can be repaired, saving money on this.

The design of LED lamps

The device of the LED lamp is slightly different from the design of the CFL. The figure shows the nodes that make up the lamp.

Diffuser. Created for uniform distribution luminous flux in space and avoid glare when looking at the LEDs.
LEDs.
The base of the LEDs with printed conductors for their series connection.
Cooling radiator. It is necessary for the removal of heat generated during the operation of LEDs.
Driver. Generates the voltage required to operate the LEDs.
Driver housing (lamp).
Plinth.

Only functional purpose needs to be explained. drivers. An LED is a semiconductor device that emits light when current is passed through it. Like a conventional diode, it only conducts it in one direction. When the polarity is reversed, the current through it is zero. As with a conventional diode, the voltage at the terminals of the LED has a value not exceeding a few volts, and does not change with increasing voltage.

Therefore, when LEDs are connected in series, the voltage required for operation is calculated by multiplying the number of products by forward voltage drop current through them. It can be found in the reference book or measured. When connecting the required number of LEDs to a 220 V AC network, you need:

reduce the voltage to the required value;
convert from variable to constant;
smooth out pulsations;
protect the driver and its load from short circuits;
protect the network from interference generated during operation of the device.

To reduce the voltage are used:

capacitor circuits;
step-down transformer circuits;
inverter circuits.

Circuits with a capacitor used in most residential LED lamp drivers. They are simple and cheap, but this is their only advantage. Functionally, they are similar to a circuit with the inclusion of a quenching resistor in series with the load, on which the excess voltage “falls”. The use of a resistor is impractical, since power is released on it, commensurate or greater than on the LEDs themselves.

The capacitor on alternating current performs the same function - it also dampens the voltage. The elements on the diagram C2, C3 and R1 are designed to lower the voltage to the required value.

The disadvantage of such a scheme is the dependence of the load voltage on the mains voltage. The current through the LEDs is unstable and sometimes exceeds the allowable values. At this point, the diodes may fail.

The second disadvantage is no galvanic isolation from the network. When repairing lamps do not touch live parts. Although the voltage on them is not dangerous, the “phase” of the mains supply can come directly.

Transformer circuits used in high-power LED lamps, inverter– with a large number of LEDs or if dimming is required (dimmable lamps).

A diode bridge is used to rectify the alternating voltage. VD1, and to smooth out ripples - an electrolytic capacitor C4.

Resistors R2 and R3 necessary to limit the current at the moment the voltage is applied to the circuit. A discharged electrolytic capacitor has low resistance and at the first moment of time the current through it is large. It can destroy the semiconductor diodes of the rectifier. In addition, these resistors play the role of fuses during short circuits. Resistor R4 discharges the capacitor after disconnection from the network for the speedy extinction of the lamp.

Details R2, R3 and R4 some manufacturers do not install. Capacitor C1 needed to prevent the penetration of interference from the operation of the lamp into the mains.

Diagnostics and replacement of LEDs

Before proceeding with the repair, remove the diffuser. Dismantling methods vary depending on the design of the lamp. Most of the diffusers are removed with a screwdriver, for which you need to pry it in several places, finding a weak spot.

LEDs need to be inspected: black dots on some elements indicate their failure. The quality of soldering is also inspected - a broken contact in a serial chain of LEDs interrupts their power supply circuit. The same happens when any of the diodes fails.

The serviceability of the LEDs is checked with a multimeter. Their resistance is measured in the forward direction. It should be small, the value for comparison is determined on serviceable elements. When tested, working diodes glow dimly. You can believe the LEDs by applying voltage to them from a 9 V battery through a 1 kΩ resistor.

The detected faulty elements are soldered from the board, and a jumper is soldered at the place of their installation. If there is a donor lamp, the LEDs are replaced, or parts from led strip with similar design and features.

Solder the LEDs carefully. To do this, the solder is first heated on one side and removed using suction devices. In their absence, after complete melting of the solder on one of the leads, it is removed by vigorously shaking the board. The remains are removed with a clean sting (you can also shake it beforehand) with a copious amount of rosin. The second conclusion is already easier to unsolder.

After installing a jumper instead of a diode, the entire lamp will glow dimmer. This is due to the fact that the total resistance of the circuit, although slightly, will decrease. The current through the lamp will increase, as a result, more voltage will remain on the capacitor. When removing one or three diodes, this will not affect the operation of the lamp. But when there are few of them left, the increase in current will become so noticeable that the remaining parts will overheat, the failure process will become an avalanche. Therefore, in the event of a massive breakdown of LEDs, leave the lamp as a donor of parts, replacing it with a new one.

Driver repair

Drivers are weak points current limiting resistors. They are checked first. You can replace burned-out elements with the same or the closest resistance value.

Examination semiconductor diodes rectifier and capacitor made with a multimeter in resistance test mode. However, there are more fast way check the correctness of this section of the circuit. To do this, the voltage across the filter capacitor is measured. The expected value is calculated by multiplying the nameplate voltage on one diode by their number. If the measured voltage does not correspond to the required one or is equal to zero, the search continues: the capacitor and diodes are checked. If the voltage is normal, look for an open between the LEDs and the driver.

Diodes can be checked with a multimeter without soldering them from the board. A short circuit in the diode or its breakage will be visible. When closed, the device will show zero in both directions, when broken, the resistance in the forward direction will not correspond to the resistance of an open p-n junction. You will recognize it on serviceable elements. A short circuit in the diodes additionally leads to the failure of the limiting resistor.

Repairing a transformer driver is a little more complicated than usual. But with the inverter will have to tinker. There are more details in it, and most importantly, it always includes a microcircuit. In order to make a conclusion about its malfunction, you will either need to study in detail the principle of operation of the driver, or make sure that all the parts surrounding it are in good condition.

Unlike conventional incandescent lamps, semiconductor ice lamps consume much smaller amounts of electricity and, therefore, are classified as economical. At the same time, the durability of their operation for some models of illuminators increases several times. Samples of modern models of LED ice lamps can be found in the figure below.

The 220 V LED lamp circuit is designed in such a way that the voltage at its output is reduced by the driver to the required value, which, as a rule, does not exceed 1.8-4.0 Volts (on each of the LEDs).

The principle of operation of LED lamps

An LED light bulb is a semiconductor element that contains several layers responsible for converting the current flowing through them into visible light.

Important! When the composition of this layer changes, radiation of a certain color (red, green, yellow or blue) is generated in it.

Since lamps that include LEDs must provide pure daylight, their developers had to use little trick, which consists in covering the blue emitter with a yellow phosphor. In this design, under the influence of blue range photons, the yellow phosphor begins to emit its own colorless radiation.

LED types

Due to various approaches to the assembly of semiconductor chips, it was possible to create the following types of LED emitters:

DIP - LED lamps made on the basis of a crystal with a lens placed on top and two supply conductors. This option is the most common in practice and is used to organize illumination in various lighting devices;
The so-called "Piranha", partially reminiscent of the previous design, but having four conclusions. An increase in the number of contacts increases its reliability and improves heat dissipation (see the figure below);

Additional Information. Such LEDs are mostly used in the automotive industry.

SMD-LED emitters can be placed on flat surfaces, due to which it is possible to reduce the dimensions of the lamp, as well as improve heat dissipation properties. They are produced in a variety of designs and are used in modern sources of light radiation;
Products manufactured using COB technologies, according to which the chip is soldered directly into the board. Due to such a device, the semiconductor ice junction is reliably protected from oxidation and overheating. At the same time, the intensity of the diode glow increases significantly.

Note! A feature of the above versions is that in the event of a burnout of the LED, it will have to be completely replaced, since it is impossible to repair these products by replacing a separate chip.

Another disadvantage of such LEDs is their small size, which forces them to be assembled in groups of several. In addition, the crystal built into them gradually ages, as a result of which the brightness of the ice emitter decreases over time. Next, the device of a 220v LED lamp will be considered.

LED diode device

The device of a 220 volt LED lamp is not very complicated and can be considered even at an amateur level. The classic 220 volt LED lamp includes the following mandatory elements:

Bearing body with plinth;
Special diffusing lens;
Heat dissipating radiator;
LED module;
LED lamp drivers;
Power Supply.

You can get acquainted with the structure of a 220 volt LED lamp (COB technology) in the figure below.

This LED device is manufactured as a single unit and contains in its design a large number of homogeneous crystals, which are soldered during assembly to form numerous contacts. To connect it to the driver, it is enough to connect only one of the contact pairs (the rest of the crystals are connected in parallel).

In their shape, these products can be round and cylindrical, and they are connected to the network through a special threaded or pin base. For a public LED system, as a rule, luminaires are selected with a color temperature index of 2700K, 3500K or 5000K (in this case, the spectrum gradations can take on any values). Such devices are quite often used for decorative purposes and for lighting advertising banners and billboards.

Consider the individual modules of the LED lamp in more detail.

Driver

In a simplified form, the driver circuit used to power the lamp from a 220 volt network looks like it is shown in the figure below.

The number of parts in this device, which performs a matching function, is relatively small, which is explained by the features of the circuit design. Its electrical circuit contains two quenching resistors R1, R2 and LEDs HL1 and HL2 connected to them in an anti-parallel principle.

Additional Information. This inclusion of limiting elements ensures the protection of the circuit from reverse surges of the supply voltage. In addition, as a result of such an inclusion, the frequency of the signal arriving at the lamps doubles (up to 100 Hz).

The mains supply voltage with an effective value of 220 volts is supplied to the circuit through the limiting capacitor C1, from which it is supplied to the rectifier bridge, and then directly to the lamp.

On a note. The simplicity of the matching device (driver) circuit makes it possible to repair it yourself.

Source of power

A typical LED lamp power supply circuit is shown in the figure below.

This part lighting device made in the form of a separate unit and therefore can be freely removed from the case (for the purpose of repairing it yourself, for example). At the input of the circuit there is a rectifying electrolyte (capacitor), after which the ripples with a frequency of 100 Hertz partially disappear.

Resistor R1 is necessary for the formation of a capacitor discharge chain when the circuit is disconnected from the power source.

Self repair

In case of failure of the simplest LED illuminator, made on the basis of individual LED elements, its repair can be done by hand. Self-repair of LED lamps and devices, the electrical circuits of which were discussed earlier, comes down to a simple replacement of faulty blocks and parts.

The body of the product is easily disassembled after it is carefully separated from the base part. Inside the structure there is a board with working LEDs, the number of which differs for different models (see photo below).

Note! In the widely used lamp model of the "MR 16" type, for example, the total number of LEDs is 27 1.5 volt elements.

In order to gain access to the printed circuit board with the diodes placed on it, it is enough to remove the protective glass lens by gently prying it with a well-honed screwdriver.

After disassembling the housing of the LED product, the following steps will need to be taken:

Previously detected faulty (non-luminous) diodes will need to be replaced after an additional check. To assess their correctness, use measuring instrument(multimeter) included in the "Continuity" mode;

Additional Information. You can check the health of the remaining elements that this electrical circuit contains by applying a voltage of 1.5 to 2.5 Volts to them (serviceable diodes should light up when such a potential is applied).

When checking with potentials of more than 5 volts, a limiting resistor with a nominal value of about 4.7-5.1 Kom is switched on in series with the element being checked;
If all the diodes installed in the board are in good condition, but constantly flicker when burning, the reason for this may be a “breakdown” of the capacitor C1.

In order to verify this, you should check its nominal capacity with the same multimeter (how to do this, you can find out in the instructions for using the device). Another approach to solving this problem involves simply replacing the capacitor with another, known to be good element, designed for a voltage of at least 400 volts.

Self-made lamp

To make an illuminator based on LEDs with your own hands, as they say, “from scratch” is a troublesome business and not suitable for everyone. It is easier to do this by using an old lamp of this type that has already exhausted its resource.

In this case, a home-made LED lamp will be assembled from new elements soldered onto a board dismantled from an old device or repaired. If working diodes remain on it, it will be necessary to replace the burned-out elements with new ones (preferably of the same type and design).

Note! In the manufacture of branded lamps, for reasons of profitability of sales, the operating current of individual LEDs is selected with an extremely high value. When altering such a device, it is desirable to solder in series with each element a limiting resistance of the order of 1 Kom.

If necessary, to make a lamp with your own hands, you can use an old board with a driver circuit, replacing all defective parts in it.

In the absence of the necessary boards and parts, the driver can be made, focusing on the above circuit of the power supply, combined with the converter (see the figure above). When finalizing, one more resistor should be added to it (let's denote it as R3), used to discharge the capacitor C2. The result is the diagram below.

In addition to the resistor, two typical zener diodes (VD2, VD3) are added to it, providing its shunting in case of an open load circuit.

Additional Information. If you correctly select the stabilization voltage of the limiting diode, it will be quite possible to get by with one zener diode.

This driver device circuit is designed to connect 20 colorless LEDs of a certain type. If their class or total number is different, the value of capacitor C1 should be changed so that the load current in the diode circuit is at least 20 mA. Its specified value guarantees sufficient brightness of the glow of these devices.

As a driver circuit, as a rule, a node is used, which does not include a bulky transformer element (such an inclusion is called "direct"). The absence of a transformer greatly simplifies the assembly of the module and reduces its size.

Important! But in this case, there is a real threat of hitting high voltage to the output of the circuit (in the event of a breakdown of a number of series-connected elements, for example). The only consolation is that this rarely happens.

In the final part of the review, we note that circuit diagrams Most of the LED products on the market almost do not differ from each other. Certain differences are observed only in the type of components used in them, as well as in the way the output voltage is generated by the driver.

We add to this that LED lamps equipped with special drivers are reliably protected from voltage fluctuations in the network, and the radiator included in their composition protects the product from overheating. The use of self-made modules due to their additional refinement can significantly extend the life of lighting devices assembled on their basis.

Video

LED lamps have moved from luxury goods to household appliances. Currently, many companies produce such light sources, since their manufacture does not require complex equipment, and the assembly scheme is simple. Now everyone can buy a miracle light source, but what to do if it suddenly stops working. It’s good if there is a guarantee, but what if it ended or didn’t exist at all? Is it possible to repair LED lamps with your own hands - let's try to figure it out in today's review.

LED-type lighting sources differ in power parameter and a variety of configurations

Before you decide how to disassemble the LED lamp, you need to understand its device. The design of this light source is not complicated: a light filter, a power board and a housing with a base.

Cheap products often use capacitors, which are designed to limit voltage and current. There are 50-60 LEDs in the light bulb, which are a series circuit. They form a light emitting element.

The principle of operation of products is similar to the functioning of semiconductor diodes. In this case, the current from the anode to the cathode moves only directly. What contributes to the emergence of streams of light in the LEDs. Parts have little power, so the lamps are made with many LEDs. To remove the discomfort from the rays produced, a phosphor is used, which eliminates this defect. The device eliminates heat from spotlights, as light fluxes are reduced with heat loss.

The driver in the design is used to supply voltage to the diode groups. They are used as a converter. Diode parts are small semiconductors. The voltage is transferred to a special transformer, where some deceleration of the operating parameters is performed. At the output, a direct current is formed, which allows you to turn on the diodes. Installing an additional capacitor prevents voltage ripple.

LED lamps are different types. They differ in the features of the device, as well as in the number of semiconductor parts.

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Reasons to repair LED lamps: device, wiring diagrams

Before you start repairing LED lamps with your own hands, it is important to find out the reasons for their failure. The stated life of the lamps may not coincide with the actual terms. This is due to poor quality crystals.

There are such reasons for malfunctioning lighting fixtures:

voltage drops do not affect the operation of electrical parts so much, noticeable fluctuations in voltage indicators can cause a malfunction;
wrong lamp. If the wrong shade is selected, the light source may overheat.
light-emitting elements of poor quality contribute to the rapid failure of products;
improper installation of the lighting system Negative influence for electrical wiring;
strong vibrations and impacts can damage such equipment.

To avoid having to make repairs led light bulb with your own hands, you need to minimize the impact of these factors on the lamp.

Note! If there are no visually determined deformations, then it is necessary to look for the cause of breakdowns using special devices: a multimeter and a tester.

Frequent problems with ice devices

Often it is required to repair LED lamps with your own hands, in case of problems with the capacitor. To carry out the test, it will have to be removed from the board. You can measure the cell voltage with a multimeter. The same device checks the working condition of the diodes.

In some cases, blinking of LED elements is observed. This happens if the current-limiting capacitor is faulty. The cause of the breakdown may be a burnt emitter. The malfunction can not be seen on all LEDs, so you will have to check every detail. A tester is used to find the problematic diode.

When making repairs, you can experiment with LED elements. For example, choose warm or cold light temperatures. Some devices do not have a smoothing capacitor and rectifier. They can be installed with a soldering iron.

Advice! If only one LED burned out, then you can close its contacts.

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How to repair an LED lamp with your own hands

If you are wondering how to fix a 220v LED lamp, then check out the standard repair schemes. The most common cause of failure is the failure of the capacitor. A multimeter is used to test this part. If the capacitor burns out, it is replaced with a new one. Another common malfunction of the lamps can be attributed to problems with the driver. When replacing this part, it is important to choose the right option.

Current-limiting resistors don't break often, but they do. You can check the malfunction using a multimeter in dialing mode. If the deviation of the indicator is more than 20%, then the device is faulty.

LEDs often need to be replaced. They should be checked only after it is clear that everything is in order with the power source. You will need a soldering iron to replace these parts. All defective elements are soldered.

The reason for the flickering of LED lighting sources is a poor-quality capacitor. To eliminate such a malfunction, it is worth purchasing a more powerful mechanism.

You can try to do your own repair of ice lamps LL - corn (corn lamps).

Image	Stages of work
	If it is impossible to find the burned-out LEDs on the case, then it is dismantled.
	Since the wires are short, the base is removed.
	To remove the base, the attachment points are drilled with a drill with a diameter of 1.5. Then the base is removed with a knife.
	Inside are drivers that feed 43 LEDs. The heat shrink tube on the driver is cut off.
	After repair, the tube is put back on and pressed with a plastic tie.
	The failure occurred as a result of high voltage. The driver is connected to the base.

Before any repair, the presence of voltage must be checked. This turns on the appropriate switch. If there is no voltage, the electrical wiring is checked and the fault is eliminated.

It is important to check the bulbs for operability, as well as the integrity of the fuses. You can ring not only integrity, but also the possible presence of a short circuit. The power supply and LEDs are also checked. LEDs can be tested with a battery. To do this, a voltage is applied to each LED through a resistor.

If a larger number of LED elements burned out in the lamp, then you need to unsolder all the old ones, and then solder the serviceable elements to the reverse side.