How to check the LED in a floodlight. How to repair an LED spotlight yourself

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LED spotlights are a type of lighting equipment that combines high efficiency and cost-effectiveness. Despite their long service life, they also fail, and their owners have to contact repair shops. However, not all faults are so complex that it is impossible to repair the LED spotlight yourself. Let's look at the causes of breakdowns, diagnostic methods and criteria by which you can find out whether self-repair is possible.

LED spotlight design and typical faults

An LED spotlight (LED) is a bright lighting device consisting of:

LED emitting light;
driver that controls the operation of the device;
housings;
a diffuser that increases the efficiency of the device;
lenses that determine the shape, color and other parameters of the light flux.

The most common malfunctions in the spotlight are driver failure or LED burnout. The latter greatly lose brightness or burn out due to the fact that the thermal energy they generate is poorly removed into the atmosphere. This problem is typical for budget manufacturers who skimp on radiators.

Combustion or unstable operation of the driver is a problem typical for Chinese-made floodlights, in which manufacturers also save on literally everything. However, using these products can be beneficial if you know how to organize electronics. Chinese spotlights are very cheap and work well after the driver has been restored.

The spotlight stopped burning - how to fix it?

First of all, in this situation, you should check whether the device driver is receiving power with a voltage of 220 V. If this is all right, you should first diagnose and repair the driver. It can be checked without connecting an LED by applying electric current to the input. If the device is working correctly, measuring the output with a multimeter should show a DC voltage that will be slightly above the rated limit. For example, for a driver with an output voltage of 28-38 volts, when running idle, the multimeter will show ~40 volts. This is explained by the fact that an increase in load resistance (due to idle operation) leads to an increase in voltage.

However, this method does not help to accurately check all drivers. There are blocks that, in good condition, will either produce illogical data or will not start at all. In such a situation, a load resistor that simulates the consumption of an LED will help you check the device. It must be selected in accordance with the characteristics of the driver. For example, with a DC output current of 23-35V 600 mA, the resistor resistance should be in the range from 23/0.6 = 38 Ohms to 35/0.6 = 58 Ohms.

If the output voltage with the load resistor connected meets the specifications, the driver operates correctly.

The easiest way to repair an LED floodlight if the driver has failed is to replace this component. You can purchase a suitable model not only in specialized stores, but also on the Internet. For example, Aliexpress offers a wide variety of spare parts, although you need to be very careful there to choose a quality product (sometimes even the sellers themselves have little understanding of the issue). Sometimes suitable drivers can be found from craftsmen who professionally repair floodlights. And if the LED spotlight was made from diodes with your own hands, then understanding its structure and fixing the problem will be even easier than buying or assembling a new one.

How to select a driver if the power of the LED module is unknown

Many hobbyists have situations when it is necessary to work with a spotlight, the power, current and voltage of the LED chip in which are unknown. Accordingly, in such a situation it is more difficult to select a replacement and driver.

Here you need to count the number of diodes in the LED matrix and add up their indicators. Such LED modules use diodes with a voltage of 3 V, a current of 300-330 mA and a power of 1 W. Accordingly, the total matrix voltage is 27 V with a current of 300 mA (when connected in series). Accordingly, a driver with an output voltage of 20-36 V is required for operation.

Let's give an example with a more complex matrix, which consists of two parallel-connected rows of diodes. Each row has a voltage of approximately 30 V with a current of 300 mA. Due to the parallel connection, the driver must have an output of 30 volts and 600 mA.

Eliminating flickering LED spotlights

Sooner or later, every owner of an LED spotlight encounters a problem. The reason for this behavior may be improper operation of electronic components or loss of performance of LEDs. In this section we look at how to repair an LED floodlight with a power of 10 W. This power is most common, and the general design of the devices is similar, so the solution to the problem is universal.

The LED is a matrix of 9 crystals, each of which has a power of 1 W. These crystals are connected in three sequential circuits and filled with phosphor - a substance that converts the received energy into light. A 10 W LED consists of three lines of crystals, which are connected in parallel to the power coming from the driver.

Burning out one of the crystals in the LED will cause it to blink during operation. The nature of blinking can be either periodic, with equal pauses, or chaotic. For various reasons, matrix combustion can lead to a complete shutdown of the LED element, or to the failure of one or two lines of crystals.

Why does the matrix blink or does not light up when it burns out?

The crystals, filled with phosphor, are connected to each other by leads, which in the case of high-quality products are made of gold, and in budget devices - of copper. Heating the matrix and connecting contacts too much causes these filaments to peel off from the crystals. Therefore, the entire matrix or part of it is turned off. After cooling, the thread returns to its original position and work resumes. After reheating to a critical point, the contact is interrupted again and the matrix goes out. This cycle continues endlessly during operation, and to the observer it looks like a flashing lamp. Complete LED failure occurs when one of the filaments overheats so much that it falls off the crystal.

Knowing about this behavior, you can check the condition of the matrix of diode spotlights with your own hands. To do this, you need to arm yourself with a not too sharp object and press on those places in the matrix where the connecting threads pass. Of course, the spotlight must be on at this time. If the device lights up when pressing on one of the paths, the problem has been found. In this case, all that remains is to correctly replace the damaged chip.

Important information! A matrix in which at least one line of crystals has burned out should be replaced immediately. The remaining lighting elements will lose efficiency and quickly fail.

This happens because the crystals are connected in a parallel-series matrix, and the power from the driver is supplied in the form of direct current. Therefore, after one line burns out, the remaining two receive a current strength 1.5 times higher than the rated one. Working under increased load leads to even greater heating of the matrix and rapid combustion of other threads.

Repairing the matrix

Replacing an LED when the crystals on the matrix burn out is not an overly complicated procedure. After purchasing a component with similar characteristics and the special thermal paste required for installation, you need to:

Disassemble the spotlight body by unscrewing the mounting bolts on the body.
Remove the lens or glass.
Remove the diffuser.
Unscrew the matrix mounting screws and carefully unsolder the conductive leads. A non-contact soldering station with a hot air gun is best suited for this.
Lubricate the new LED with thermal paste.
Solder the contact pins of the LED and screw the fasteners back on.

When connecting an LED, it is extremely important to maintain the polarity of the terminals. Experienced installers also recommend replacing the wiring when replacing an LED in inexpensive Chinese floodlights. Manufacturers, as a rule, use material with a minimum cross-section, which is not entirely reliable. In this case, it is better to use heat shrink tubes. They retain their insulating properties even when exposed to heat emanating from the diode.

No one will deny that LED lighting sources such as floodlights are effective in illuminating large spaces. The compactness of the device and the power of the luminous flux, as well as the evenness of the lighting of the space, make LED floodlights popular for private use in country houses. The industry also produces them in the form of portable devices, which is very convenient.

It happens that the device begins to work incorrectly, the spotlight begins to blink, and an even glow occurs. Let's look at how you can fix this problem and the reason for its occurrence.

How does an LED floodlight work?

In order to understand why the LED spotlight blinks, let’s look at how it works and what its design is:

the housing of the LED device can be made of impact-resistant plastic or metal;
There is an LED lamp inside the housing;
reflectors.

The spotlight works on the principle of directing the light flux with the help of reflectors to a certain point, they collect it, for this reason a bright glow is obtained.

The LED, whose task is to provide an even light, consists of a semiconductor element and electrodes, these are the anode and the cathode. When the required voltage appears on the electrodes, they heat up the semiconductor element, and it glows. For the scheme to work you must have:

a special type of rectifier, driver - they must stabilize the current and regulate its value;
power supply for the LED, since it needs 12 volts.

Many breakdowns can be avoided in the future if you pay attention to the following nuances when purchasing:

An LED device is a lighting device with high illumination parameters and low electrical energy consumption. Important! Such systems cannot be cheap if they are well made.
When purchasing an LED spotlight on the Internet, a consumer may encounter various breakdowns that arise due to the cheapness of the models:

after a short interval of operation of the device, the light flux blinks, even when the device is turned off;
The motion sensor supplied with the device stops working.

While trying to achieve cost competitiveness for their devices, manufacturers often neglect quality and reliability; If the spotlight blinks, the following reasons are possible:

bad soldering;
the cheapest batteries and low current control parameters are selected.

As a result of saving materials and reducing the cost of the lighting device, the buyer after a short time experiences problems with its operation. Often, due to the fact that the boundary current is not regulated, the spotlight begins to blink.
There is an opinion that some manufacturers who are focused on Russia install current limiters in their LED devices, without taking into account our regional specifics (frequent fluctuations in electrical energy), which leads to breakdowns.

What are the most common causes of LED spotlight failure?

Not a single perfected device can guarantee operation without breakdowns; there is always a possibility. LED systems, for all their reliability, have frequent malfunctions when LED spotlights flicker. The reasons for this phenomenon always lie in the device itself and its operating conditions.

Motion Sensor

When a motion sensor is purchased in conjunction with a spotlight, and the light flux blinks when supplied, the reasons may be the following:

Incorrect setting of the motion sensor itself - because of this, the LED spotlight blinks. It is necessary to correctly set the timer in the sensor; it is this that keeps the LED system in working condition for the set time; you need to check whether the device is working properly; When all manipulations have been completed, we check the system in operation;
faulty, floating contact - when the sensor is triggered, but the signal from it does not pass to the spotlight. It is necessary to check all internal switching wires, inspect them for integrity, tighten all contacts secured with a screw connection;
the motion sensor has been faulty since the moment of purchase - this problem cannot be solved on your own, you must return the product to the store and ask for it to be replaced;

The motion sensor is continuously under current load and part of it passes to the LED spotlight - a small amount of voltage on the spotlight will not be able to turn it on to full light, but will cause a blinking effect.

Weather

A malfunction in the form of blinking LED spotlights when it’s frosty outside also occurs with popular suppliers of LED devices. The reason for this phenomenon is the appearance of icing on the elements responsible for the LED glow. This phenomenon begins to manifest itself at a temperature of –10 degrees, despite the fact that the technical specifications indicate the operating temperature of the device from –50 to +50 degrees. These parameters are correct, but only for the LED itself, and not for the elements that turn it on.

LED device elements

The solution to this issue is the possibility of bringing the device into the house during the frosty period during daylight hours and taking it back to work at night.

Spotlight mode

Many modern lighting devices have additional modes, and the reason that your LED spotlight is shining may be that this mode is accidentally activated. Experts recommend turning the device off and on and seeing if the glow mode is removed as a result.

In addition, the glow can also be caused by the fact that, in accordance with the design features, several functions are activated by one power button. And by clicking on it twice, you activate the effect of working in strobe mode, as a result of which the LED spotlight blinks.

Lighting in the switch

Very often, LED spotlights are purchased to illuminate the space of a private home, and a backlit switch is used to turn them on.

It is this design of the switch that can flicker at a certain time interval. The reasons for this flickering when the spotlight is turned off are as follows:

the LED in the switch does not completely interrupt the circuit, and the insulated wires play the role of a capacitor, simultaneously performing the task of a conductor in alternating current and its rectifier;
The supplied voltage is enough to start the LED spotlight, but it is not enough to maintain combustion.

It is easy to fix such a breakdown; you need to disconnect the LED in the switch from the power supply or change the switch to a simple design that will work when turned on, and is guaranteed to interrupt the power supply when turned off. Experts also recommend the following to eliminate this type of problem: a capacitance with parameters from 0.1 to 0.5 microfarads must be included in the circuit, as well as a resistance with a power of 2 watts per 50 kOhm, how this can be assembled is shown in the figure below.

Other reasons

Sometimes it happens that all possible reasons for the blinking of the spotlight or its weak flickering have been checked, but it stubbornly continues to do so, what to do in this case? Experts suggest that in this situation, the flickering of the LED spotlight occurs due to induced voltage, which can arise when the main wires going to the spotlight switch pass through the same channel.

To start the LED system, a small voltage is needed, but it is not enough to maintain the glow, which causes the lamp to flicker. In such cases, it is necessary to include in the circuit a ballast having a resistance of about 50–60 kOhm and a power of at least 1 watt.

There is a possibility that after replacing the LED spotlight, the blinking will disappear; this may be due to the quality of the internal switching of the devices, as well as what elements are in the device.

There are cases when the manufacturer of floodlight LED lamps, specifically to improve the brightness of the glow, removes a capacitor from its circuit and increases the value of the limit current, but in this case the matrix of the device is exposed to temperature, the diodes burn out, and the device goes out of stable operation.

The operation of LED systems is greatly influenced by the environment in which the spotlight is operated - at high temperatures, the spotlight may have a dim glow or flicker when the temperature is ten to fifteen degrees below zero. In this case, the cause of the failure is uneven heating or cooling of the driver, which stabilizes the voltage.

Do repairs or buy a new one?

Floodlights do not belong to the category of cheap goods, for this reason even LED systems can be repaired. If you have experience with electrical work, then it is worth disassembling the floodlight system. All lamps can be disassembled, even sealed LED ones.

According to the general opinion of experts, the main culprit for the failure of such floodlight systems to operate normally is a non-working driver. The power supply in the LED system is the weakest point in terms of operational reliability.

In addition, the disadvantage of floodlights of this type is poorly thought out heat dissipation; for this reason, the thermal paste with which the matrix is attached to the board hardens, the light output decreases, and the lamp begins to burn dimly.

If you decide to repair an LED spotlight, you need to select replacement elements for these purposes; they need to match the current and voltage. Sometimes, when selecting parts for replacement, a master can find out for himself what is easier - buying a new spotlight or repairing an old one, since the cost of replacement is slightly less than the cost of a new device.

Conclusion

In conclusion, we emphasize that when the spotlight turns on independently, you need to do the following:

check the device connection;
change the type of switch;
If the spotlight works with a motion sensor, check it for compatibility with the LED device.

Experts pay attention to the fact that the reason for this phenomenon may be the low cost of lighting devices; they do not guarantee long-term operation. When doing repairs, you need to be able to handle a soldering iron, electrical measuring instruments, read connection diagrams and a circuit diagram of the device.

One of the modern types of LED light sources for street lighting is an LED floodlight. The electrical circuit of an LED spotlight is not fundamentally different from that of an LED lamp. The main difference lies in their design, since it is required to ensure operability in a wide range of temperatures in precipitation conditions. Therefore, repairing spotlights with your own hands is not much different from repairing LED lamps and is even simpler, since there are no difficulties during disassembly. To gain access to the driver and LEDs of the spotlight, just unscrew a few screws.

Repair of low-power LED floodlight

I received two identical LED spotlights of type SDO01-10 with a power of 10 W for repair. During an external inspection, a malfunction was immediately discovered in one of them - partial peeling of the protective layer and the presence of a dark spot on the light-emitting surface of the LED matrix.

The hope of repairing a spotlight with a faulty LED matrix immediately disappeared, since the cost of such an LED emitter usually exceeds half the cost of the spotlight. And purchasing a new matrix is very problematic, since LEDs usually do not have markings and it is difficult to determine the type of non-standard emitter. The appearance of the second spotlight did not raise any questions.

I decided to simplify the repair task by moving the driver of the spotlight with a burnt-out matrix into a spotlight with a working one. But removing the back covers showed that the drivers in both spotlights were faulty.

In both drivers, the 1 Ohm protective resistors burned out, which indicated a breakdown of one of the diodes of the diode bridge or the key transistor.

Repair of a high-power LED spotlight

Once again I had to deal with the repair of a more powerful spotlight of the SDO01-30 type with a power of 30 W.

The appearance of the spotlight is shown in the photograph. In terms of overall dimensions, it is slightly larger, and the design of the spotlight repeats that of the above presented model.

After removing the back cover from the spotlight and inspecting the appearance of the radio elements on the printed circuit board, no suspicious-looking parts were found.

Inspection of the printed circuit board after its removal from the side of the printed conductors immediately revealed two burnt-out resistors, R8 (2 Ohms) and R22 (1 Ohms). Typically, low-resistance resistors burn out due to the large current flowing through them when semiconductor devices or capacitors break down. Next to the resistors there was a powerful field-effect transistor SVD4N65F, which turned out to be faulty during dialing. The electrical circuit of the spotlight was not available and we had to find out the values of the burnt resistors by opening a working spotlight of the same type.

The faulty resistors and transistor were soldered off and all other semiconductor elements were additionally checked on the printed circuit board. After sealing the working resistors and transistor into the printed circuit board, the spotlight started working.

As you can see, if you have the skills to work with a multimeter and a soldering iron, you can successfully repair any LED spotlights with your own hands.

The repaired spotlight has been working properly for several years. The second one was also recently repaired, thanks to the emergence of a new type of LED matrices, which do not require an additional driver, since it is already installed on the matrix substrate. The matrices are no more expensive than classic products.

In addition, it was possible not only to restore the functionality of the spotlight, but also to increase its power three times, while achieving a zero pulsation coefficient.

LED floodlights are in great demand among consumers for illuminating shop windows, store facades, courtyards in private homes and other objects. They are durable, have good light intensity and consume much less energy compared to conventional incandescent lamps.

But any equipment has a certain service life and is not guaranteed against breakdowns, therefore it requires repair. It is always cheaper to fix problems yourself than to contact specialists in workshops. Let's look at a simple repair of some faults on LED floodlights, but before describing the repair process, you need to study what types of floodlight designs there are and the principle of their operation.

LED spotlight operation

The voltage from the power source is supplied to the electronic board, the converted current is supplied to the LED element, which emits streams of light. The designs of spotlights may be different, but they all have common elements:

Power supply;
Electronic current and voltage conversion board;
Operating mode control drivers;
Heat sink;
Optical elements, lenses, mirrors built into the body;
Terminals for connecting wires and fixtures for fastening the housing.

Floodlights have LEDs of different sizes and power, but the principle of operation and symptoms of malfunction are common.

Basic spotlight malfunctions

Most often, the malfunction of spotlights is manifested by the following symptoms:

Complete absence of glow when turning on the power;
LED flickering;
Dim glow, not at full power;
Changing the shade of emitted light;

There are obvious signs of deformation of the housing, destruction of the LED structure, after mechanical shocks or breakage, burnt out wiring, which are visible visually.

Main causes of malfunctions

Manufacturers make LED matrices and conversion boards that are reliable and, if used correctly, guarantee a minimum trouble-free period of up to 5 years. Most often, malfunctions occur for the following reasons:

Unstable characteristics of the electrical network, voltage and current surges exceeding the operating mode values;
Short circuit of a phase to the spotlight body or neutral wire;
Incorrect connection;

As a result of these violations, the electronic board on which the floodlight control drivers, voltage and current converters that power the crystal structure of the matrix with LEDs are programmed may fail.

The LED matrix in spotlights can consist of several dozen elements. If the structure of 3-5 crystals in the matrix is destroyed, the spotlight can function, but with a larger number of faulty elements, irreversible processes disrupt the operating mode and all the crystals burn out. In this case, a complete replacement of the matrix is required.

Diagnosing a fault on an LED floodlight

Let's consider identifying a fault on a floodlight, which is in greatest demand among consumers, rectangular in shape with a matrix of 9 diodes, with a power of 10 W. One of the models in this series is the Volpe 10W floodlight with a luminous flux of 750 Lumens.

Regardless of the brand of spotlight, diagnostics begins with a visual inspection:

The integrity of the wiring from the power source is checked, the absence of breaks, burnt insulation and kinks in the cable, where there may be a break in the current-carrying conductor hidden under the insulating layer;
The body of the spotlight and the LED matrix are inspected for absence of deformation, cracks and chips;
If there is no light at all, first of all you need to unscrew the back cover of the case and check the voltage at the input and output of the electronic board of the converter. There should be 220V AC at the input; if there is no voltage, then the reason is not in the spotlight, but in its power supply circuit; measurements can be carried out with a conventional multimeter. The output terminals are 12V DC.

If there is no voltage at the output, the fault should be looked for on the voltage converter board. Inspect the board for oxidized contacts, tin cracks in solder areas and burnt parts;
If there are no signs of malfunction in all of the listed points, the last element remains, this is the LED matrix.

Repair and replacement of faulty elements of LED spotlights

Faults such as broken wires can be resolved quickly and do not require special qualifications. The most difficult repair is identifying a faulty element on the driver circuit board, voltage converter and replacing the LED matrix. Therefore, to make repairs yourself, you must have certain knowledge and practical skills in electrical engineering, be able to read diagrams, use measuring instruments and a soldering iron. If you don’t have such experience, it’s better to turn to specialists.

The simplest way is to replace faulty elements with similar ones; they can be purchased from electrical goods or removed from spotlights on which other parts are faulty. Assemble one working one from two or three faulty ones. A matrix with LED crystals filled with compound material cannot be repaired.

Tip No. 1 If 2-3 diodes out of 9 have burned out in the matrix, then you don’t have to wait for it to burn out completely; this can have a detrimental effect on the drivers and voltage converter. Change the matrix at the first sign of malfunction.

Replacing the spotlight matrix

Unscrew the front cover of the case, which presses the glass;

Unscrew the screws and remove the reflector;

Unsolder and unscrew the faulty matrix;

We solder the new matrix and assemble the spotlight in the reverse order.

Sometimes the wires from the printed circuit board pass to the matrix through holes in the metal substrate, which acts as a heat sink for the matrix. At the transition points, they must be insulated, especially the positive wire, so that there is no short circuit to the housing.

Tip No. 2 When replacing the matrix, wipe its substrate and the surface on which it is screwed. Lubricate these places with heat-conducting paste, only then screw the matrix to the body.

When replacing the matrix, be sure to observe the polarities, the red wire is positive, blue or black is negative, yellow-green is on the body.

Although LED technology (including spotlights) is highly reliable, it also sometimes fails. Repairing LED spotlights allows you to eliminate most faults when you need to restore the functionality of the device. Repair work is relevant not only when the device does not shine brightly enough, but also if it completely stops working.

Operating principle and diagram

The LED spotlight (LED) includes the following components:

LEDs (provide glow);
drivers (control the operation of the device);
frame;
light diffuser (allows you to increase the efficiency of the lamp);
lenses (control the shape, color and some other characteristics of the light flow).

The spotlight operates thanks to the coordinated actions of several of its components, including optics, power supply, drivers and heat sinks. The inside of the case contains light diodes, as well as small electronic components. The power supply supplies voltage to the LEDs, where the current is transformed into light output. Thanks to these actions, the device glows.

The figure below shows a standard electrical circuit for an electronic spotlight driver.

As for the operating principle of the driver, it does not differ on different spotlights. Power from the mains is supplied to the driver input, bypassing fuse F1. Next, filtering occurs using LC elements and rectification using a diode bridge. Smoothing is carried out by an electrolytic capacitor (C13). DC voltage (280 V) is generated at the capacitor terminals.

From the electrolytic capacitor, the voltage is directed through current-limiting resistors to the zener diode (D12) and pin No. 6 of the described microcircuit. The zener diode is responsible for the 9-volt power supply to the microcircuit, which is the main factor ensuring the functioning of the driver. From capacitor C13, current flows through the transformer winding (T1.1) through the lead part of the field-effect transistor (Q1).

Note! The amount of current flowing through the light diodes depends on the resistance parameters of the resistors on the microcircuit.

Signs of a spotlight malfunction

The most common signs of a malfunctioning spotlight:

the lamp does not light up, although the power is turned on;
the light diode flickers;
the glow is too dim, as the lamp burns weakly - not at full power;
the shade of the light flux has become unnatural.

Other signs may also be present, including physical damage to the structure of the case, deformation of the diode, burnt out electrical wiring.

Causes of failure

Possible reasons for the spotlight not working properly:

Unstable electrical network (voltage drops beyond the operating current);
short circuit of a phase to the device body or to neutral;
incorrect connection;
overvoltage;
use of overcurrents.

In the event of these violations, the board on which drivers, voltage and current converters are installed, supplying power to the matrix crystals, may fail. Damage to 3 to 5 crystals in a floodlight matrix is allowed. If the number of faulty crystals is greater, the spotlight will not be able to operate with a sufficient degree of functionality and the matrix will need to be replaced.

Diagnostics

First of all, it is necessary to determine the cause of the LED spotlight malfunction. As an example, let's talk about checking the performance of a rectangular Volpe spotlight with a matrix including 9 diodes. The total power of the lamp is 10 W. The luminous flux is 750 lm.

The check is carried out in the following order:

Inspect the wiring for physical integrity. Check for breaks, burnt insulation, or kinks in the cable. The purpose is to ensure that there are no breaks in the conductor.
Check the device body, as well as the LED matrix for mechanical damage (deformation, chips, cracks).
The next task is to check the input voltage by opening the back panel of the case. The input voltage should be 220V (AC). If there is no voltage, the cause of the breakdown is not in the lamp, but in the electrical circuit. Measurements are carried out with a standard multimeter. The output voltage is 12 V (DC).

If there is no output voltage, the breakdown is looked for on the converter board. Inspect the contacts for oxidation, look for cracks in the tin coating in areas of soldering or burnt-out elements.
If the above verification methods do not produce results, test the performance of the matrix.

Replacing parts

Eliminating broken wiring does not require special qualifications from a home technician. It is much more difficult to find and fix a breakdown on a printed circuit board, driver, voltage converter or matrix. You can't do this without special knowledge. You will also need the ability to work with diagnostic instruments and a soldering iron.

The following parts may be subject to repair or replacement:

limiting capacitor;
power unit;
driver;
matrix.

Current limiting capacitor

This component causes a malfunction when the spotlight lamp burns unevenly, constantly flickering. This problem is usually associated with the fact that manufacturers, in an effort to save money, install a current limiter that does not match the characteristics of the driver.

power unit

A common cause of malfunctioning of the spotlight is a breakdown of the power supply. In such a situation, you can purchase a new power supply or pick up this part from another device (for example, from a printer). If you decide to buy a new unit, it is recommended to take it with you to the store, since its technical characteristics are indicated on the case. To get the block, you first need to disassemble the spotlight.

Driver

Low-power models often lack a power supply. In such cases, an LED driver is used instead of a block. Since the diode is not able to receive power directly from the network (an alternating current other than the mains is needed), the driver is used. The device operates based on operating temperature and time, changing the output current to the LED.

To replace the driver, you should disassemble the spotlight to set the technical parameters of the driver, and then contact the store. Just as in the case of a power supply, you can select a suitable driver from another device.

Matrix

The most common cause of spotlight malfunction is excessive heating of the matrix, which leads to blown fuses. The spotlight is disassembled, after which the damaged matrix is taken out. To do this, unscrew the four screws and solder off the conductive parts. Next, apply a layer of thermal paste to the LED and solder the conductive parts back. The operation is completed by screwing the matrix into place.

In some cases, the wiring in the matrix goes through the holes in the substrate. It acts as a matrix radiator. In the transition areas, the wires must be covered with an insulating layer (primarily we are talking about the positive wire). This will avoid a short circuit to the device body.

Advice! Before replacing the matrix, you should clean the substrate and the area where it will be installed. It is recommended to treat these areas with a heat-conducting compound.

The shape of the matrix must not be disturbed. It is recommended to use only “original” screws so as not to damage the design. Also, do not forget about the polarity: the red wire is positive, the black or blue wire is negative, the green-yellow wire is directed to the body.

If at least 2-3 burnt-out diodes are detected, you should not wait for the matrix to burn out completely. In any case, the device is no longer able to function normally, as a result of which the drivers and voltage converter will soon fail.

Note! If the matrix does not work with a filled compound element, it cannot be restored.

Voltage converter circuit board

If, when checking the board, obvious signs of burnt-out elements are found, the device will need to be repaired. The figure below shows a converter circuit for a spotlight.

Before replacing non-functioning parts, you should ring the LEDs. First, one of the board legs is unsoldered, since ringing the soldered elements will not give the correct result. If necessary, burnt out parts are replaced with new ones.

Low power floodlight repair

As an example, let's look at the repair of the SDO01-10 floodlight. Device power - 10 W. An external inspection shows peeling of the protective coating on one of the floodlights. There are also dark spots on the light-emitting surface of the matrix.

Repairing a matrix with a damaged LED emitter is possible, but such a part is not cheap. The cost reaches 40-50% of the price of the entire spotlight. In addition, purchasing a new matrix presents another difficulty - most often there are no markings on the LEDs. As a result, it is not easy to determine the type of emitter.

To simplify the task, we install the spotlight driver from the burnt-out matrix to a lamp with a working matrix. On the old driver, the protective resistor burned out (its value is 1 Ohm), which indicates a breakdown of the diode in the diode bridge at the transition from the key resistor to the control resistor. However, replacing the driver did not restore the functionality of the spotlight.

After further testing, a break in the optical feedback pair was detected. Replacing the pair gave results - the lamp started working.

Repair of a powerful spotlight

The subject of consideration is the model of a powerful spotlight SDO01-30. Devices of this type are used for lighting large rooms (for example, industrial purposes).

First, we remove the back panel from the spotlight and visually inspect the condition of the radio components on the printed circuit board. We pay attention to elements that look suspicious (carbon deposits, deformations, etc.).

Next, we inspect the printed circuit board (pulling it out of the spotlight) from the semiconductor side. An inspection revealed the presence of a pair of burnt-out resistors: R8 (2 ohms) and R22 (1 ohms). Resistors with low resistance most often burn out due to the high current passing through them in the event of a breakdown of semiconductors or capacitors.

Next to the resistors is a field-effect transistor SFV4N65F. The ringing determined its malfunction. Since the spotlight circuit was not available, we find out the values of the resistors that burned out by disassembling a working lamp of the same model.

We unsolder the failed resistors, as well as the transistor. We replace them with new parts.

Some useful tips for repairing LED floodlights:

When replacing the matrix, be sure to pay attention to the polarity.
Be sure to remove the hardened heat-conducting paste under the matrix.
The surface should be degreased with alcohol.
When soldering, you do not need to overheat the surface. Soldering time is up to 2 seconds. If the matrix is overheated, the crystals will be destroyed or their new characteristics will not allow the spotlight to function normally.

To repair a high-power spotlight, the knowledge used in repairing low-power lamps is sufficient. There are no special differences between devices of different power.
If a matrix with a large number of diodes is not filled with a compound solution, the non-working diode will need to be replaced. To perform this operation, a micro-soldering iron is required. You need to work carefully so as not to overheat the crystals.
If it is impossible to see the values on the burnt-out resistances, you cannot do without the instructions for the spotlight. It must contain the relevant data.

Anyone can fix a spotlight. However, to perform repair work, at least basic knowledge of electrical engineering is required, as well as skills in using a soldering iron and a multimeter. You also need the ability to read diagrams to understand the design of the spotlight.