Why LED bulbs blink: troubleshooting + how to fix

Today, people are massively switching to the use of energy-efficient lighting. This is done with the hope of obtaining a number of important advantages, including efficiency, durability.

But it often happens that users instead of the expected result immediately meet with signs of malfunction. Therefore, the question of why LED lamps blink is quite often confronting the consumer.

In this article, we will look at all the most common causes of the blinking of LED lamps, and also describe ways to find a fault in the lighting equipment.

Why do cheap lamps flicker?

Probably, there are no more people who have not heard that cheap products of little-known manufacturers should not be bought, since this is fraught with varying complexity with negative consequences.

This happens in the case of LED lamps, which often even immediately after purchase begin to blink, which does not please the owners.

But such a mode of operation in most cases does not indicate the presence of a breakdown. That is, the lighting device is usually in good condition, but it is exposed to any adverse factors that interfere with normal functioning.

And if they are eliminated, the flickering will stop, and there will be no relapse. But it is more practical to prevent such phenomena and all that it needs to do is to acquire quality products from well-known manufacturers.

At the stage of purchase, they will cost more, but high performance will ensure long-term operation. And without losing the best properties, but it is expensive. Since cheap lighting fixtures save only on price.

And then the person is faced with their predisposition to various irregularities and other negative consequences, including a negative impact on health.

Modern LED bulbs They are always sophisticated technological devices consisting of many components. Among them is a driver whose task is to stabilize the electric current.

And this is an important task, since high-quality and long-term work depends on its characteristics, and not on voltage, as many believe.

Additionally, the driver is able to cope with various side factors that lead to flicker in the off / on position of the switch.

But it is an obligatory part of the construction only of high-quality and, therefore, not cheap lamps. And in their available counterparts of Chinese and even domestic origin to save this key element is always replaced with a cheaper power supply.

It is based on such structural elements as a diode bridge equipped with a capacitive filter and a damping capacitor. Which are able to provide high-quality lighting, only when the characteristics of the electric current is ideal.

In this case, the work cycle is as follows:

1. Initially, alternating current passes through a diode bridge, where it is converted into a constant one, which is necessary for LED lamps, but with a high ripple.
2. To impart a stable electric current, it is fed to a capacitive filter. And from there to the quenching capacitor, which finally smoothes the pulsation.
3. The current with the desired characteristics goes to the lighting devices, allowing them to regularly perform their duties.

But with non-ideal electric current parameters, the power supply unit with its cheap components is not able to cope with the pulsation and its straightening, which ultimately causes a blink.

In addition, signs of such a malfunction can occur both in the off and on state.

And the features of each type of abnormal work should be known, as this will help eliminate the defect. And quickly and often without any major costs.

Blinking when the switch is off

This type of malfunction is manifested due to the fact that the electric current, even when the control body is inoperative, enters the smoothing capacitor.

There it accumulates and, when filling all the available volume, falls on the launching circuit, which tries to bring the LED lamp into working position.

But a tiny supply of electricity is only enough for a short flash. Further, the procedure begins with a new one and can continue until the cause of the light fixture is eliminated or broken.

Causes of abnormal work

The blinking frequency is different and depends on the amount of electric current passing through the power supply of a cheap lamp.

But we must understand that this is not the cause, but only the consequence of the incorrect functioning of the other elements of the chain. And they should know to cope with the task, and without extra costs and wasted time.

Despite signs of malfunction, the product, in most cases, remains working. Just the power supply is unable to prevent instability by smoothing the ripple.

One of the LED lamps blinks due to the following stimuli:

• backlight switch;
• induced voltage;
• presence of leakage currents.

Since the knowledge of the signs of the causes of the malfunction will help identify them and promptly eliminate them, you should deal with each of them separately. Moreover, it will be possible to the user who is far from this sphere.

Flashing due to backlight

For convenience, many manufacturers equip their switches with backlights. And in most cases they are beneficial, increasing the comfort of the owners, as they are easier to find in the dark.

But when using such a control in conjunction with inexpensive lamps, the current applied to the backlight LED can cause flashing. This happens because the specified structural element is connected in parallel with the switch itself.

This feature leads to the fact that in the on position, all the electric current is used to power the LED lamps used, and in the off position, it ensures the implementation of the backlight.

At the same time a small amount of electricity is able to get further to the capacitive filter and extinguishing the capacitor, and then, having reached the desired performance, it gets to the lamps, causing blinking.

Moreover, this reason is the most common, so the user is always worth remembering about it. And when restoring the performance of indoor lighting attention to switch illumination It is worth paying always, and in the first place.

Induced blinking due to induced voltage

In the post-Soviet space, they often like to save on quality. That induced voltage is a consequence of this. Since most often it occurs when one stranded wire is used to power several devices, rather than several, as it should be.

Although it sometimes happens that when laying independent electrical wiring lines in a single gate, interference may also occur due to the induced voltage.

But it only happens on disconnected sites. And usually influenced by wiring, which feeds electrical appliances operating under high load.

And although such interference is insignificant, there is enough of their capabilities to influence the LED lamps. Which as a result of active influence begin to blink frequently, which leads to their rapid failure.

And the worst thing is that the lighting device purchased for replacement will face the same negative factors.

When do leakage currents pose a problem?

This reason is the most serious of all. Since abnormal operation of any LED lamps can lead to quite flammable reasons.

These include:

• wrong or poor quality wiring;
• damaged or collapsing insulation;
• bad contact

Often, when performing work, the human factor influences and specialists violate all sorts of elementary rules.

As a result, after breaking the circuit, that is, when the switch is set to the inoperative position, the current still flows to the electrical devices. This happens if a zero phase is confused.

Damage to the insulation may occur due to careless handling of the wire during installation or operation. In addition, it often loses its performance after prolonged use, that is, when its resource has developed.

Another cause of leakage currents is poor contact between wires and other circuit elements. This happens even with the usual oxidation, which can occur within a few years after the start of their use, and even more quickly in difficult conditions.

Ways to eliminate the causes of blinking

If the flashing occurs due to the presence of a backlight lamp, then the simplest way to restore normal operation is to break its circuit. That is, it is necessary to dismantle the switch and just bite the necessary wires.

It will not affect the characteristics of the appliance, but the backlight will not function in the future. In addition, a simple method is to replace the switch - this can be done quickly.

And you should also know that there are two types of lights: neon and LED. And when using the first flicker is much less common - this is information for those who do not want to complicate the search for a switch in the dark.

If you use a group of LED light sources, then instead of one of them you can install the most low-power incandescent lamp. It will work as a resistor, turning the current into heat and dissipating it into the air.

Thus, the flicker can be avoided, but the aesthetic properties of the chandelier will deteriorate significantly. Since in most cases the incandescent lamp will not be masked.

Another proven option for eliminating the causes of abnormal operation is to add a low-power resistance of 50 kΩ, with a power of 2 W to the circuit.

But it should be understood that such an element increases the fire hazard. Therefore, the work needs to be done qualitatively and not less responsibly to the isolation of contacts.

The effects of the induced voltage, most often, are eliminated by the above methods. But it happens that the signs of malfunctioning do not disappear.

For example, sometimes you can see a blink even after replacing a switch with an analog without a backlight. In this case, only a cable replacement will be an effective option, and if there are several of them, it will be necessary to place them at some distance from each other.

Leakage currents are eliminated only by checking the correctness of the wiring and the elimination of deficiencies, that is, by replacing the circuit elements in poor condition.

In the worst case, you will have to replace the wiring throughout the apartment. Especially it concerns cases when in a room with a blinking light bulb is used for a long time outdated and inefficient grounding system TN-C, which does not exclude the possibility of human injury electric current.

Flashing when the switch is on

In this case, there may be only two reasons, so it is easier for the user to find and fix them. But it should be remembered that this should be done quickly, since the durability of LED lamps depends on it.

Causes of blinking may be:

• weak tension;
• poor quality power supply.

All LED lamps are sensitive to low voltage, but high-quality copies with a driver instead of a power supply are able to work stably within 180 V. Then, as the economy options completely stop working - they go out, they just do not turn on - already at 200 V.

And, if the voltage is slightly higher, but does not reach 220 V, then the user will observe flicker with a different frequency. And it will stop when the network parameters stabilize to normal.

Also, a malfunction may occur when attempting to dim an LED that is not intended for this. In this case, its performance at the maximum position of the dimmer will be normal, and if you try to reduce, flicker will start.

Instructions for connecting the dimmer can be found in this material.

If the mains voltage is normal, then you should pay attention to the power supply of the product used. The reason, as described above, may be that its components simply cannot smooth out the current ripple, which leads to blinking.

To prevent abnormal operation in any of these cases, you can install stabilizer, which will provide the current with the necessary parameters, and at the same time prevent early breakdowns of electrical appliances used by the owner.

If the voltage is normal and the cause is in the poor-quality components of the power supply, then the user will be able to upgrade it. To do this, you need to replace the installed smoothing capacitor with a more powerful one, and an advanced user will be able to independently assemble a reliable driver.

Moreover, this characteristic is not limited by the parameters, but by the size of the free space in the power supply unit, the lamp base. This ensures smoothing of the current ripple and ensures its parameters stability.

How to find the cause?

Each user must remember that the speed of his actions to eliminate blinking is very important. Since any LED lamp has a resource to turn on, which can be developed in just a few days.

In addition, damage to the wiring or its isolation may be a danger to human health.

The search itself must begin with checking the correct connection of the phase conductor. It must always be connected to one of the switch contacts.

If it is found that the current is coming to the backlight lamp, then this will be the cause of the flashing. The test can be carried out using an indicator screwdriver that can be done by each person.

When this stage has been passed, and the malfunction has not been eliminated, you should replace the switch with a similar product without illumination, install a low-power resistance, or use a glow lamp. If the flicker stopped, then we can assume that the person coped with the task.

But when the problem has again manifested itself, the wiring should be inspected to identify damaged insulation, oxidized contacts, a series of power cables, and other problems.

Which will need to be eliminated even if such operations turn out to be labor-intensive and expensive. So as soon as it can guarantee the absence of danger to the health of people.

If blinking occurs in the on position of the switch, then the voltage and its stability are initially checked.

When the parameters are normal, you should replace the LED lamp with a high-quality analogue of a well-known manufacturer. These are high-tech products from OSRAM, Philips and a number of others.

Conclusions and useful video on the topic

How to return the lamp performance by installing the resistance shown in the video:

The following video gives an overview of several more ways to eliminate the flashing of various LED lamps:

The flashing of LED lamps is a very common phenomenon and you don’t need to be afraid of it, because in most cases it is easy to eliminate. In most cases, it is enough to change the switch.

But the very manifestation of such a deficiency indicates that they use cheap and low-quality products that do not inspire the confidence of manufacturers. And imaginary savings costing additional costs and time lost on trifles.

If you have the necessary experience or knowledge, please share it with our readers. Please leave your comments, ask questions in the box below.