How the garland burns. A simple tester for checking the New Year's garland

A couple of years ago, a simple device was created to search for a burned-out light bulb in a chain of serially connected New Year's garland bulbs:

This is a very simple and really workable device. However, it exposes the user to lethal voltage. The probe shown above is inserted into the socket of a light bulb, so there is a risk of accidentally touching the probe when its probe is energized.

In the new version of the device, I made an LED probe. The garland plugs into an outlet that connects to a 9V battery, not AC power. In other words, the operation of the device is similar to the neon version of the device: you use a probe to find a burned-out light bulb in a string of lamps. Touching one side of the burnt bulb will light the red LED and the other side will light the green LED. By checking the chain back and forth, you will quickly identify a burned out light bulb.

The advantage of this scheme is that after the repair of the garland, the yellow LED lights up, which indicates that the repair work has been completed.

Picture 1New Year's garland tester scheme

Figure 2

List of radio elements

Designation	Type	Denomination	Quantity	Note	Shop	My notepad
	Comparator	LM293	1			To notepad
	Capacitor	0.1uF	1			To notepad
	Resistor	100 kOhm	4			To notepad
	Resistor	1 MΩ	2			To notepad
	Resistor	750 ohm	1			To notepad
	Light-emitting diode	AL307B	1			To notepad
	Light-emitting diode	AL307V	1			To notepad
	Light-emitting diode	AL307E	1

Instruction

Stock up on several garlands equipped with light bulbs with the same parameters. One of them will be a "donor" of lamps for the repair of the rest.

After disconnecting from the network, open the controller. See if any wires are unsoldered from the board. On one of its sides there are two contact points for connecting a power cord, on the other - five pads for connecting color channels. One of these sites is located away from the remaining four - the common wire of the channels is connected to it. Often, on the soldering to these sites of the conductors that have soldered off from them, the repair ends. When you're done with the controller, close it.

Some garlands are equipped with lamps that self-short when burned out. The lamp in which the shorting device has worked has a lower resistance than the good one, which is why the rest of the channel lamps operate in forced mode. Therefore, burned-out lamps in such a garland must be changed to serviceable ones as soon as possible. They can be taken from the "donor" garland. Replace by de-energizing the garland, carefully solder all connections and insulate with several layers of electrical tape.

If there are no shorting devices in the lamps, if one of them burns out, the entire channel goes out. It is clear that calling each of them separately will take a lot of time, so you have to use the iteration method. After turning off the power, cut the channel exactly in the middle. Ring the sections of the channel from the beginning to the middle and from the middle to the end. Now it is clear in which of them the burnt out lamp is located. This section can also be divided in half and ring both halves of it, and so on until the burnt out lamp is found. Replace it by taking a serviceable one also from the “donor” garland. After that, reconnect the wires in all the places where you cut them. Thoroughly solder and insulate the connections.

Light bulbs are a particular danger in a garland. When turned on, they instantly burn out, while between the thread holders, which are not isolated by anything, the full mains voltage begins to act. Such lamps should be replaced immediately with serviceable ones.

Never close a burned out bulb or bulb instead of replacing it with a new one, otherwise the rest of the channel bulbs will be over-voltaged and burn out faster.

Repair of the LED garland is distinguished by two features. The first of them is that the new LED must be turned on in the same polarity as the other diodes of the same channel (a rectifier is installed in the controller of any garland). The second feature is the need to include a resistor in series with each of the LEDs. Its value should be the same as that of the resistors on the other diodes of the same garland. It is impossible to mix light bulbs and LEDs in the same garland, since the former usually have a rated current of 50 or 100 mA, and the latter - 20.

After completing the repair, before continuing to use the garland, be sure to carefully inspect it for the presence of uninsulated connections. Isolate them carefully.

If on the eve of the New Year you find out that the old Christmas tree garland does not work, for example, one color does not light up, do not rush to buy a new one, because. there is a chance to repair the damage with your own hands. Fortunately, the device of these Christmas tree lights is not too complicated, and if you carefully check all possible faults, you can make repairs at home. Next, we will tell the readers of the site how to fix the garland if the contact wires come off in it, the light bulb burns out, or the modes do not switch.

One or more colors not lit

One of the most time-consuming breakdowns is considered to be the case when one or two colors do not work in the electric garland, for example, only red or yellow and blue, as in the photo below. This indicates that, most likely, the bulbs in the corresponding section have burned out.

To begin with, we still recommend disassembling the switch cover, also known as the control unit, and checking the reliability of all connections - contacts soldered to the board. We immediately suggest watching a video lesson from a young master, which clearly shows what to do if the wire from the board breaks:

How to perform the simplest repair of a malfunction?

If everything looks in order, then with a high probability it can be judged that the light bulb has burned out. The fact is that modern garlands are designed in such a way that all single-color lamps are connected in series and if any one burns out, the light will go out on the entire electrical branch. To fix the breakage, it is recommended to proceed as a good old textbook advises: cut the garland in half and ring both sections. Then proceed in the same way with the non-working section: cut by 2 and check again, and so on until the end, as shown in the diagram.

As a result, you will be able to determine which light bulb is not working and replace it. We draw your attention to the fact that it is advisable to use this repair method if the electric garland is non-separable, usually Chinese.

To quickly fix the garland with your own hands, you can take a tester and attach needles to its ends instead of probes. With the help of needles, punch through each section of the circuit in series so that the needle passes to the current-carrying core, and look for where the resistance of the section is significantly different. In this way, you can find a breakdown and repair it with less effort.

Old Soviet garlands for the Christmas tree (without a box) are more convenient in this regard, because. in them, all the lamps are screwed into the cartridges, and you can determine which bulb does not work without a soldering iron and an ohmmeter by elimination - taking a working light source and screwing it into all the cartridges one by one. Another repair method is to use a tester to measure the resistance of each lamp until you find a blown one.

An example of repairing another difficult malfunction:

Why does the Soviet electric garland not work and how can I repair it myself?

Another way to fix a broken electric garland is to check the integrity of the common wire. On the board on one side you will see 5 soldered wires: 4 for the glow of each of the colors and one common. Now, if the common wire breaks, you just need to solder it.

In addition to the light bulb, the reason that one or more colors are not lit in the garland may be a broken wire, which is responsible for just a certain color. This problem most often occurs if there are cats or dogs in the house that chew through the wires while playing. In this case, you need to find the place of damage, re-twist the current-carrying wires and insulate them. It does not hurt to provide after that.

Doesn't light up at all

If your LED garland does not shine, and you are convinced that it is not the LEDs, then you already need to look at the control unit and the power cord. First, check the integrity of the cord, it may have been interrupted or the contact on the connection to the microcircuit has broken. After that, check how all the contact connections are soldered to the board. For example, in the photo below, one of the wires burned out. If everything is working, then the board has burned out. You can, of course, buy a new garland if this one was cheap Chinese, but if you want to fix the product, now we will tell you how to do it.

Instead of a standing control unit, you can use a starter from a fluorescent lamp for 127 or 220 Volts (the difference is only in the speed of flashing the bulbs). First, check how the LEDs are connected. If it turns out that the extreme elements of the groups are interconnected by anodes, you will have to redo the circuit and connect the LEDs with cathodes. This is due to the fact that for normal operation of the starter, the voltage to the anode must be supplied through a 5-watt resistor with a resistance of 15-20 kOhm. In addition, diodes will also have to be included in the circuit, as shown in the diagram below. Diodes are needed in order to pass through the reverse current of the network. This is how you can remake and thereby fix the LED garland with your own hands at home.

As you can see, you will have to take care to repair the product, so if the electric garland is Chinese, it is better not to waste time and buy a new one. About that, we told in a separate article. By the way, it is recommended to convert it to a starter even if the garland does not blink or does not switch modes and the reason for this is the controller.

We draw your attention to the fact that if it is the LED that burned out in the Christmas tree diode lamp, after which the entire section does not light up, you need to solder the serviceable element strictly observing the polarity!

Broken light bulbs

If one or more bulbs are broken and you want to repair the product, we recommend that you simply replace the damaged one with a new one. We draw your attention to the fact that the replacement should be done only when the power is off, so as not to get an electric shock. In this, of course, unbreakable lamps are better, because. such a defect bypasses them.

If you don’t have a spare microbulb at hand, you can safely cut off the broken one and connect the wires without it.

Well, the last thing I wanted to say is that if your tubular garland (duralight) does not work, try visually and with a tester to find the problem area and cut it out in the places intended for cutting (marked with scissors). After that, connect the working sections with special connectors, on which the repair will be completed!

That's all I wanted to tell you about how to fix a garland if one color does not light up or the board burns out. Now, you know what to do to repair the breakdown yourself!

As a rule, garlands have a rather simple design and typical malfunctions that are easy to fix even without special skills and tools. But in some cases, you may need a soldering iron and a multimeter. Therefore, you may still have to turn to a familiar radio amateur.

The cause of a garland malfunction, like any electrical engineering, is the failure of one or more circuit elements. Everything is usually repaired by replacing a faulty part, which can be found in another garland or some kind of broken equipment.

Careless handling of the electric garland can result in an electric shock or damage to the device. You perform all actions at your own peril and risk. Lifehacker does not bear any responsibility.

samelectrik.ru

All electric garlands are arranged in the same way. In older samples, these are light bulbs connected in one circuit that light up or flash when connected to the network. In modern ones, a controller is added to glow in different modes and the bulbs can be replaced by LEDs.

It often happens that a garland that has lain all year in the closet stops working. Many find a way out in buying a new garland. However, if you wish and have minimal knowledge, you can repair the LED garland with your own hands.

Components of an LED garland

Outwardly, a garland based on LEDs is similar to an old type device: the same wires, light bulbs, control unit. However, the technical essence of the system lies in the control unit. It is a small plastic box, which displays the various options for the operation of the backlight. To change the lighting mode, just press the corresponding button. Blocks of various designs are produced, including those with a high level of protection against moisture and dust (protection class - IP44).

To see the inside of the unit, you need to remove the protective cover. To do this, use a thin screwdriver or a knife to pry off the cover. On some models, the lid is snap-on, so no special tool is needed. Inside the block there are conductors soldered to the board. The thickest wire is usually the mains wire (it supplies voltage).

The board contains the following components:

• controller for creating lighting effects;
• thyristors (one for each channel);
• resistors;
• capacitor;
• diode bridges.

The number of board components is determined by the number of garland channels. The most expensive modifications are equipped with fuses.

Garland scheme

The operation diagram of the LED garland is shown below. The mains voltage is supplied to the supply controller, passing through the resistors and the diode bridge. The voltage enters the controller in a rectified and smoothed state (thanks to the capacitor).

Voltage passes through the button, open in the normal position. If the button is closed, the controller modes are replaced. As for the controller, this component is responsible for controlling the thyristors. The number of thyristors is determined by the number of channels in the lighting system.

After passing through the thyristors, the output power is sent to the light diodes in the garland. The number of outputs directly affects the variety of colors produced by the lighting device. If there is only a pair of outputs, then the simplest scheme is implemented, in which one half of the bulbs fades out, and the other lights up.

Two diode lines are connected to two channels in series. The connection is made at the last point - the light diode.

Note! One of the mains voltage wires is always sent straight (bypassing all circuit components) to the end diode of the garland.

Causes of failure

There are many reasons that can cause a garland to malfunction:

• insufficient contact on the conductors;
• a failed light diode in one of the lamps;
• failure of a capacitor or thyristor;
• burnt controller chip.

The microcircuit on the board does not burn often. Among all the reasons, burnt microcircuits are found in about every tenth case.

Problems and Solutions

Below are the most common breakdowns. Repairing the garland is really do-it-yourself: this will require care and accuracy.

Poor solder quality

Poor soldering of the supply and outgoing conductors is the most common cause of backlight failure. In some cases, the contact is held solely on hot-melt adhesive, so its performance is out of the question. It is enough to lightly touch the conductor, and the contact is completely broken.

Especially often low-quality connections are found in Chinese-made garlands. Also, manufacturers from China, in order to save money, often use too thin wires that easily break at the junction with the board.

Advice! To avoid tearing off the contacts, the soldering points must be filled with a layer of hot melt adhesive of sufficient thickness.

Another way to avoid wire problems is to stop stripping the wires with a knife. During such an operation, it is easy to overthinn the wire. It is better to strip the conductor using heat treatment with a lighter fire.

LED damage

To find a faulty diode, turn off the garland from the power supply. We start the test from the last LED in the circuit (a conductor from the power supply goes directly to it). An outgoing wire is attached to the same leg, going further to the next branch of the light channel.

You will need to test the LED between a pair of power wires (input and output). As a test device, we use a multimeter with slightly modified probes. To upgrade the probes, we attach thin needles to their ends with a thread. The tip of the needles should protrude quite a bit - by 5-7 millimeters. Apply a layer of insulating tape on top.

Since all the diodes are connected to the soldering circuit, simply removing them from the lamp (as is the case with a conventional garland) will not work. We pierce the insulating layer of the cores to find copper wires.

We switch the device to the LED ringing mode. We begin to pierce the supply conductors near each diode over and over again.

If the tested garland is not 220 V, but 12 or 24 V, the working LED will light up. If we check the system for 220 V, we pay attention to the indicators of the multimeter. On serviceable parts of the circuit, the indicators will be approximately equal, but the defect will reveal itself as a break.

Chaotic flicker

Another common problem is erratic flickering of light bulbs. Diodes blink for no apparent reason, their brightness changes randomly.

The cause of this malfunction is the improper operation of the electrolytic capacitor. This element is usually deformed - it looks somewhat swollen.

The way out of this situation is to replace the capacitor. Its nominal value is always written on the case.

If the situation does not improve after replacing the capacitor, the problem may be a blown resistor. Visually, such a defect cannot be detected, therefore, in this case, you can not do without a tester. We measure the resistance, not forgetting to know in advance the value for the component. If the result obtained does not correspond to the nominal value, we change the resistor.

No light in one of the areas

If any of the channels is completely out of light, the cause may be one of two factors:

1. Breakdown on the thyristor or diode of this channel. To make sure that the cause of the malfunction is correctly determined, we unsolder the channel wire on the board and connect a new channel instead of the old one (which definitely works).
2. If the above method did not bring a positive result, the problem is not in the garland, but in one of the elements of the board - a diode or thyristor. Using a multimeter, we check these components and, if necessary, change them to working ones.

dim lighting

There are situations when there is lighting, but one of the channels gives too dim light. At the same time, the controller circuit functions without problems, and when the buttons are pressed, normal mode switching occurs.

Ringing diodes using a multitester also does not work. There is only one possible reason - low-quality wires. If some part of the stranded conductor is torn, the total cross section decreases, which is expressed in the dimness of the light. This is due to the fact that the required amount of voltage is not supplied to the LEDs.

To find the gap, you will need to manually check the entire wire line. You will have to be patient, because the defect in the line is quite possibly located on the last thread to be checked.

When the problem area is found, we disassemble the conductors on the LED, clean them (preferably with a lighter) and re-solder. Next, we apply an insulating layer using heat shrink.

broken lamps

If one or more lamps turned out to be broken and it was decided to fix the garland, it is recommended to simply change one LED for another. Repairing such bulbs is technically impractical.

Note! Diode replacement is carried out only when the power supply is off.

If there is no spare light bulb, we remove the broken light source and connect the wires without his participation.

LED ringing

Finding a burnt wire and other defects is easy with the help of a dial. LEDs are characterized by indicators that determine their working environment. These include voltage and operating current. These parameters vary depending on the type of light diode. The most important parameter is the current strength. These indicators should be taken into account when the LED is ringing independently. If the current and voltage are unknown, it is recommended to use one of two reliable ringing methods:

• using a multimeter;
• using a standard battery.

Note! Before checking the LED bulb, it must be unfastened or unsoldered from the contacts.

The diode is a semiconductor product (that is, it passes electricity in one direction) and is equipped with two contact parts (anode and cathode). Contacts are made in the form of copper legs.

We put the tester in ringing mode. In this position, the current through the LED will be approximately 1 mA. We touch the probes of the multitester to the legs and look at the readings shown on the monitor of the device.

Advice! It will be easier to notice the glow of the LED if the room is darkened.

We make a ringing in two positions - this will allow you to set the position of the cathode and anode of the working light diode. If the device is faulty or does not give enough light, the multimeter will show one.

In the absence of a tester, ringing is performed using a standard 9-volt battery. Since a direct connection of the diode to the battery leads to its breakdown, you will need a step-down device - a resistance resistor. However, since the operation assumes the absence of any auxiliary means, except for a battery, we use a finger moistened with water as a resistor. With the anode we touch the plus of the battery, and put our finger on the minus and bring the cathode to it.

Garlands produced in Soviet times are distinguished by their reliability. Another feature of them is that they can be repaired, while not all Chinese-made products can be repaired. Modern devices and tools allow you to identify a malfunction and carry out repair work.

Necessary set of tools and materials:

• soldering iron;
• screwdriver-indicator;
• insulating material;
• pliers.

The garland uses a serial connection scheme. In other words, if one bulb burns out, the entire system stops functioning.

We check the lamps for integrity. If the light sources are not damaged, check how they are screwed into the cartridges. If necessary, screw the lamp into the cartridge to the end.

Advice! If you need to replace a colored light bulb, but a replacement is not available, it is recommended to paint the light source with zaponlak.

If the actions described above did not give a positive result, we take an indicator screwdriver and look for a contact interruption site in the conductor. A broken contact is not necessarily in the wire, so we also check the cartridge. If the problem is in a broken contact, we restore its functionality using a soldering iron. If necessary, connect the conductors directly.

Alteration of the Chinese garland

Most consumers have a not very good opinion about Chinese products. Garlands also do not stand out against the general background of goods from China: poor-quality connections, too thin conductors, cheap construction materials. As a result, such garlands (including their control units) often fail.

Failure of any of the elements of the circuit can affect the functioning of the garland. For example, a non-working capacitor causes the bulbs to flicker. Breakdown of the thyristor entails the shutdown of one of the channels. A blown diode, a failed diode bridge lead to the complete inoperability of the system.

Advice! If you need to change the flicker frequency, it is recommended to add a 0.5-2 uF capacitor to the circuit.

Damaged parts must be replaced with new ones. In the absence of sufficient knowledge in the field of electrical engineering or unwillingness to mess with repairs, an extremely simple but effective scheme is recommended. We connect the garland directly with a plug, and we build a starter from a fluorescent lamp into one of the cable conductors. However, this scheme is effective only for conventional light bulbs. As for the LED garland, its performance in this case will be restored, but the light will become dimmer.