Why does not it show TV? Why the TV does not display the picture under normal sound

In the home appliances market, LCD (LCD) TV has taken a worthy place, along with LED, which proves them. Manufacturers introduce the latest technologies in devices and expand the functionality of devices. Despite the release of new models of plasma technology, the devices are still failing. Many users are familiar with the situation when the display does not broadcast a picture. In this case, it is necessary to find out the cause of the malfunction and call the master. This article discusses why there is sound on the TV, and there is no image on the screen, and how to fix the system's defects.

Problems with video images of monitors are very common. In most cases the display does not glow at all. But there are other situations:

• the picture flashes, with a ripple;
• the video signal is interrupted;
• on the right or on the left is visible;
• blinking backlight;
• in the image, squares or stripes appear;
• on the contour of the video image, red or green edging;
• on the screen vertical colored strips;
• the picture is barely discernible.

Causes of image loss

The reasons why the image disappears, but the sound is, can be a great many. It is not always possible to independently determine what exactly could break, and professional diagnostics will be required in the service center. No need to blame the manufacturer, since a similar defect occurs in different TVs: Samsung, Lg, Sony, Philips and many others. It happens that the TV turns on, a screen saver appears, after which the showing display goes out.Channels with the help of the remote control are switched at the same time, and sound can be present.

The main reasons can be the following:

• the connecting cord disconnected from the socket;
• the wire is damaged;
• broke the inverter, supply voltage to the backlight lamps;
• the matrix, motherboard, backlight unit is faulty;
• defect in convector, loop or decoder;
• in the power unit, electrolytes failed;
• the uselessness of the electrolytic capacitor;
• in kineskopnyh TV defect in the frame or line scan;
• went the loop from the matrix to the board.

Tips in those cases where the LCD TV does not have an image, but there is a sound following.

1. Check the quality connecting cable. The wire that has become unusable should be replaced with a new one.
2. On the back of the unit, check the connection of the cord to the socket.
3. Increase the volume to maximum. After this action, the device will again operate in the same mode.
4. Avoid any mechanical impact on the TV set.
5. Check device settings. Enable or disable the output channels of the instrument.
6. If network disruptions are a frequent occurrence, procure an uninterruptible power supply.
7. In order not to aggravate the situation, contact the technical service center.

Note! Our recommendations apply only to a working monitor. In this case, the splash screen appears when the technology is turned on. If the TV does not show the splash screen and the display is dark, it indicates that some screen element does not function correctly.

Test the cable

In the event that the sound is reproduced on the unit, but there is no image, you need to check the quality of the wire. Use the programMoninfo. The utility is designed to check the transfer of video and audio. If the program fixes failures, it becomes clear that the problem is in the connecting cable. From this, it would seem, insignificant details, the quality of the image in principle depends very much.

Troubleshooting Televisions Samsung

First, you need to test the video signal by following these steps:

• on the panel select the button with the image of the house;
• go to settings;
• select options "support", "self-diagnostics", "run image test".

After the problems are issued, try to solve them using manufacturer's recommendations:

As you can see, many faults can be eliminated by hand. Even if yours - this too can be fixed at home.

Note! If the test is not displayed, the fault is internal, in the device itself.

Watching TV is one of the common hobbies of people of all ages. TV is in every family, and not always one. Many have already changed the old picture tubes for more modern TVs. But both new and old TVs are not immune from breakage. Let's look at the situation, why not show the TV.

The type of TV and the cause of the breakdown

At this point in time, TVs are divided into different types of image output. These are old - kinescope, more modern - plasma TVs, LCD TVs and the newest models - with LED-backlighting. The reason why does not show the TV screen depends on the type of your TV. For example, if you are the owner of a kinescope TV, then, most likely, out of service came out a kinescope. If you own a plasma TV, then the plasma fades inside the TV, the LCD most often fails the pixels, as well as the backlight lamp. More accurate information you can get from a specialist in the service center, and the cause of the failure can be learned by conducting a special diagnosis.

Causes of poor image

Poor picture quality may not always indicate a breakdown of the TV. This can be quite a poor provision of cable or satellite TV services. If the TV does not show the channels, first you need to make sure that the cable of your antenna is working. Also it does not hurt to try to configure or reconfigure channels. To do this, you need to use the setup menu of your TV. You need to make sure that your equipment can receive data from cable or satellite TV services, since not all decoders have decoders for receiving and decoding the signal. It will not hurt to make sure of timely payment for the services provided by television. Perhaps you just turned off the service for non-payment.

Quite often people have to face the situation when the image is, but its quality does not suit you. In order to understand why the TV is bad, you need to identify the very cause of the malfunction. For example, the cause may be a malfunction of the TV itself (pixels, kinescope, decoder or other equipment), and poor-quality provision of services. If you are sure of the quality of the services provided, timely payment and other points, then the reason lies in the TV itself. Self-repair equipment should not be engaged, especially if the TV is currently on warranty. Remember that any independent repair threatens not only the loss of warranty and the TV itself, but it can also damage your health, for example, you may be electrocuted. Therefore, repair and adjustment should only be handled by a specialist.

One day our TV does not show our favorite programs. Accordingly, we are surprised, angry, how did it always work, and suddenly the bang and there is no signal.

This situation occurs very often to me, which prompted me to write this article, on behalf of the antenna master. We all do not stand still, we constantly grow and develop, so does technology, and television does not lag behind. Everything is done for our convenience and comfort, television is broadcast in two formats, it's analog and digital, and it's free.

This is not enough for us.

We buy equipment and do not hesitate what to install, adjust the antenna for digital television is not easy. Attached, twisted the cable, connected the receiver or amplifier, as the sellers call, not having an understanding of what exactly is needed.

The result is basically one, there is no signal, why is it so? We cry out in misunderstanding !!! After all, they promised and assured us, and they paid money.

Start saving now, entrust this business to a professional, and let the professional install, configure or repair. This will save us nerves, time and that the main money.

A good bonus to all that the responsible specialist will always take on further maintenance, and whatever happens, will sort out and eliminate the problem that has arisen.

A troubled problem.

Ask why I write this? I answer, today the customer asked a question, we looked 12 years and suddenly everything disappeared, how, this can not be?

Maybe everything once comes to an unsuitable state, breaks down and requires replacement or repair. The TV antenna is no exception. For a long time I was trying to prove the opposite, but having carried out all the checks on the measuring instrument and having checked all the connections, the customer was convinced of my correctness.

The secret of a good TV antenna !!!

I do not use active, only passive.

The choice of a location for installation, direction and definition of height, and that is equally important knowledge and experience of the television master, that's the whole secret.

And do not buy kits without having any experience, and what is even more dangerous is the seller's advice. From where he can know what exactly you need, not knowing all the complexities and tasks with which ballet is necessary to collide.

We are, we need to communicate, specifically set goals and objectives, and then everything can be done.

Repair of antennas is simply as many people think. Here comes a specialist on the subway or train with a screwdriver in his pocket, a little twist, something will adjust and that's it. No, I will say right away that professional equipment and tools are needed to solve problems, and this can only be transported by car. Therefore, you can make 2 kopecks, but what will be the result, it will not be hard to guess.

Qualitatively does not mean expensive, but work and knowledge cost money, which I appreciate and respect, and I constantly develop, which I wish you.

My name is Sergey Stakh, always at your service, read my articles and ask questions, we will decide together

Below is the picture of the inverter. Simplified, but it will be possible to understand why it does not show the TV, fix the malfunction. What kind of beast is an inverter, how to handle it? Let's answer the question, learn something new about modern technology. The subject is close to welders, similar methods are used to ignite the electrode. Plus in the adjustability. The pulse width modulator easily changes the effective voltage of the primary winding of the transformer by varying the current. An increased frequency is used to reduce the size. At ultrasound, the transformer takes up much less space.

Inverter power-on circuit

The work of modern TV

There is a sound, there is no picture - the breakage concerns the schemes of the formation of the image. Can refuse the scan, but in most cases the matter is explained by the following. Previously, the radiation tube dominated in television, the tripled attention was paid to the posistor, today LCD monitors can not do without lighting. Moreover, the quality / price of the device mainly depends on this. Various methods are used for lighting, usually ordinary halogen lamps covering the perimeter or part. Organic diodes are not affordable for everyone. Lamps for ignition, combustion require the creation of a discharge. The process of ionization of gases is impossible without high voltage. How to get in a miniature (relatively) device?

The correct answer is a transformer. To get a thousand volts from twelve volts, look for a large transformer ... Therefore, a pulse generator is used, controlled by a pulse width modulator. Simply put, the key, the inverter. Tactured in the circuits cuts the signal, in our case it forms the necessary steepness of the pulses, so that the transformer can easily pass through. Determined by the width of the pulses, the signal power changes. So the current is regulated:

The question arises: why is an inverter needed, if the pulse width modulator could control the transformer itself? It is connected with loading ability. The chip has a certain power dissipation limit. A series of microcircuits are tried to be hidden in the same housing, achieving uniformity. It is possible to combine an inverter and pulse-width modulator in one circuit, they do infrequently, the current consumption of the assembly will increase. Consequently, the power dissipation will increase. Will lead to a violation of the same type.

The inverter is a simple circuit, often on one key element. Therefore, with it, it is easy to obtain a significant output current without loss of uniformity. The resolution key is usually formed by semiconductor transistors. The power reaches the brightness control, the voltage level of which controls the pulse width modulator. More pulse width, brighter image. Entering the lower branch (see figure) the signal repeats the form, controlling the winding of the transformer. The secondary circuit generates a current. The backlight is lit.

The feedback current is compared with the signal of the brightness controller of the comparator, which is part of the pulse-width modulator. In case of a mismatch, the pulse duration is adjusted in the desired direction. That's the whole inverter. It is familiar to welders, converts a constant voltage into an alternating voltage by controlling the signal parameters. Increased voltage, welders need a significant arc burning current.

Repairing the TV Inverter

It happens, the TV screen does not show, the sound is there. In most cases, the problem concerns the backlight lamps, the inverter. It is logical to start testing from here. Thanks to the design features, it is difficult to get to the backlight lamps, the fault detection is started by the electric circuit. Inverter. Find the presence of a transformer on the board, do not confuse it with the power supply (where the TV cord goes).

At the input should be 12 volts, measure the value of the tester, check the integrity of the fuse. If burned, wait a little, usually means - something broke inside. After applying 12 volts, check the power supply on the brightness regulator circuit. Without it, the screen will turn off. Voltage zero - the transistor wrench is to blame. Correct the replacement of the burned elements. The transistors ring for a short circuit.

The enable signal is called Enable, it is fed by the electronic board of the TV. Undock the connector, apply 12 volts to the power and 5 volts to the Enable. Lamps light up - the TV board is faulty. Otherwise, continue the search. It's time to conduct an external inspection of the capacitors, transformer, connectors for the inclusion of lamps. Defective parts are easy to distinguish:

• Resistors turn black.
• Transformers melt the protective film.

If, after starting the circuit on the lamp, a voltage surge appears, it is necessary to clean the contacts. It is useful to try to insert serviceable. High probability - the backlight will work again. It happens, the lamps will blink after turning on, immediately go out. Indirectly indicates the failure of the feedback loop, or overload.

It is necessary to check the capacitors in the branches of the lamp, ring the transformer windings (zero resistance indicates a short circuit), then check the elements on the feedback loop. Transistors, capacitors, diodes, resistors, etc. It is important to know the features of the operation of various microcircuits, the technical sheets usually indicate the permissible modes. Often helps to identify a malfunction with the appearance of a conventional circuit. Some elements do not pull the load, create the wrong conditions.

The behavior described above, when the lamps, flashing, go out, is characterized by the disruption of the oscillations of the pulse-width modulator. The output of the transformer is nothing. If you find a device for measuring the frequency, connect a 100 kΩ resistor to the lamp connector. The oscillations of ultrasound and above (tens of kHz) should be recorded. Depending on the brightness settings, the frequency changes: with increasing, the frequency increases.

The measured parameters do not correspond to the nominal values ​​- the primary winding voltage generation circuit is to blame. After the inverter there are several elements of filtering / signal optimization. Chokes, transistors, resistors. They are checked in the usual order for good. With unstable brightness, blinking, the suspicion concerns the central circuit of the TV, or the pulse width modulator.

TV settings are lost

Occasionally, the channel setting has failed. The memory chip of the TV does not belong to the backlight. In this case, the screen is rippling, there is no sound. TV is slow to show channels, it is necessary to check the shares of the provider. Admire, www.youtube.com/watch?v=YtqrIVaEDNI#t=11. The video says: without updating the software, Tricolor TV channels will be refused. The problem is easily eliminated by performing the specified actions.

Broadcasting is carried out by the DBV-T2 format - the channels are split by multiplexes. One frequency transmits many transmissions, the TV uses the built-in adapter to extract information broken by frames, converting it into a form that is digestible for the screen. Failure to configure the multiplex, disappear all the channels that are part of the composition. It is necessary to know the frequency of broadcasting. Corresponds to the number of the digital television channel. After you need to visit the TV menu, start searching for channels at the selected frequency. When the operation is completed, the list of caught stations, signal level, quality should appear on the screen.

In some cases, the antenna is to blame. In our region, a cable, especially a satellite cable, is often cut off. And not at all with the purpose to hand over to the point of reception of non-ferrous metals, considerations of competition. The action is very difficult to track and punish. In some cases, local providers are trying to crush "heavenly", broadcasting on the satellite. It is trite to check the quality of the connection. In the event of a break, the receiver will not see the converter or disjec.

We hope, answered the question, why does not the TV show, what could break, how to correct the attack. Now readers can find the malfunction themselves. Please note that the backlight should be removed as neatly as possible so as not to damage it.

Many TV owners face a problem when the sound is working and the image is missing. Of course, there is a reasonable question: why does not the TV show and how to eliminate the breakdown? The most effective way to solve the problem is to contact a specialized company "In repair!" Immediately after the breakdown is detected. The wizard will make a deep diagnosis of the device and eliminate the identified malfunctions directly at the customer's home. As a rule, the restoration work takes no more than 2 hours.

But it is worth noting that some of the breakdowns can be eliminated on their own. To do this, you must perform the following actions:

• check the integrity of the antenna cord and the reliability of its connection to the TV;
• configure / reconfigure channels;
• make sure that the services of cable television were paid in time.

Why is the black screen on the TV?

Channel broadcasting can be terminated due to maintenance. In such situations, the broadcast is interrupted for several hours. To make sure that the reason is really in this, and not in the breakdown of the TV, you need to switch to other channels, and if they are working in the normal mode, then you just need to wait a bit and the channel will be restored automatically. While carrying out preventive works, a special screen saver is usually displayed, but you can often see a black screen on the TV, which can frighten the user.

If the problem persists for a long time, we recommend that you contact the representative of the company that provides TV services to clarify the details. However, it is also desirable to check the balance on the account, because the company can suspend the service because of delay.

Why does not the TV show yet?

To broadcast TV channels, many TVs use special signal receivers. But such antennas have one drawback - they do not catch the radio signal badly under unfavorable weather conditions. Thus, with precipitation or even strong cloudiness, a signal can be scattered, which can cause the broadcast of channels to temporarily stop or be broadcast with interference. Solve the problem by installing a more powerful antenna.

In addition, the cause, due to which there is no image on the LCD TV, may be damage to the antenna. Usually damage is caused by hail or strong wind, which can bend and render the receiver unusable. Antennas that have a significant surface area may not withstand a large mass of snow - under the influence of weight, some of the antenna elements may be deformed.

Due to unfair mounting, the antenna may slightly turn to the side due to strong wind. Even a small error is enough to stop catching the TV channels tuned on the TV. This problem happens rarely, however, this option should not be excluded. If it is a satellite dish, the user must periodically make adjustments to the settings of its settings. This is due to the fact that the flight path of the satellite can vary slightly.

Why did the TV stop showing channels?

Each TV channel has a certain broadcasting frequency, so the TV is tuned to the appropriate channel frequency so that it can receive the signal. If you have a problem with the playback of analog channels, you need to consider this factor. In the event that a reset occurs, the TV will not be able to catch the desired signal. A similar problem can occur for various reasons, but most often it is a hardware malfunction that automatically returns the factory settings.

Signs of such a problem is spontaneous change of the number of all or several channels at once. Also, it is possible that most TV programs are out of order. For a normal user, the configuration process can be too complicated, so a specialist should do it. If the services for broadcasting channels are provided by the operator, then you need to call the support service.

The cause of interference can be excessive signal amplification. This function is only used in cases where there are problems with signal reception, in other situations it is capable of doing harm.

What should I do if the image disappears on the LCD TV?

If the TV does not show not because of the above problems, then for troubleshooting it is better to ask for help in the service center "In repair!". We specialize in diagnostics and restoration of equipment at home. The presence of professional equipment allows us to identify breakages of any complexity, for example:

1. breakdown of the image forming unit;
2. matrix failure;
3. failure of the inverter, the function of which is to turn on the backlight and ensure its operation (the problem usually occurs in LCD TVs);
4. burnout of the backlight lamp is a common failure when there is no picture on the TV, but there is sound.

Turning to the company "In repair!", Our customers can rely on qualified assistance from experienced masters. In case of need to replace unusable parts, we use certified components that can ensure a long and trouble-free operation of the TV. At the same time, the price policy of our company is democratic.

What if the TV does not show, but does it have a sound?

Possible solutions for solving problems:

1. Replacing the inverter. This part is one of the most vulnerable LCD TV panels. The inverter performs functions to turn on the backlight, which ensures a "soft" start of the device and the required brightness level of the backlight.
2. Replacing the backlight. This part is directly behind the liquid crystal panel. Thanks to it, light is produced, which provides visibility of the picture on the display. The operation to replace the lamp is one of the most difficult and laborious, because apart from disassembling the case, it is necessary to dismantle the LCD matrix of the TV.
3. Replacing the imaging unit. In plasma panels, this component is responsible for the transmission of images on the Y and Z diagonals. When it breaks, the TV does not show the image, but the sound is working properly.

Repair work is carried out as quickly as possible: within 1-2 hours you can enjoy watching interesting TV programs.

How to order the services of our company?

1. You apply for a visit to the house. The time of a specialist's visit is determined by you, therefore, determine in advance the most appropriate time interval. The application can be issued by phone or by using the "Call me back" form.
2. Diagnosis of the TV. Before proceeding to work, the wizard will perform diagnostic work that will reliably determine the cause of the malfunction and determine the best option for eliminating the problem.
3. TV repair. After agreeing the price and other nuances, the specialist begins to work. After completion of the restoration work, a warranty will be issued.

The company "In Repair!" Carries out its activities in Moscow and St. Petersburg. For detailed information on the provision of services, you can contact our manager by contacting him by phone. Contact information is available in the "Contacts" section.