Why do vertical or horizontal stripes appear on the TV screen


Vertical or horizontal stripes on the LCD TV screen or computer monitor are not a pleasant defect that will not allow you to use the device. Even if they periodically disappear, it still indicates a malfunction of the matrix, loop, or circuit elements.

Stripes on the screen

How to identify a malfunction by the nature and type of stripes on the screen

Most often, horizontal stripes appear on the TV screen when motherboard components or connecting signal cables are damaged. They are of several types, by which one can judge the class of breakdown and possible actions. In particular, the nature of the stripes will show a person with a certain level of knowledge how much he will approximately have to pay for the repair of his apparatus.

White line on the screen indicates that the control signal voltage is not supplied to the liquid crystal cells of the matrix. This display behavior is typical for TN and VA displays. They are transparent in the normal state, without the activation of light-transmitting cells. In IPS matrices, the picture is different. In the normal state, they are perfectly black, so the white stripe indicates a high control voltage.

In any case, the presence of a bright bar on the display indicates a problem with the vertical scanning system. This is a separate hardware component of the TV. Its diagnostics requires special equipment and is carried out only in a service workshop. The whole block may need to be replaced. But in any case, contacting the service is mandatory.

Colored stripes (blue, lilac, purple) indicate problems with the LCD controller. They can indicate both failures in microprocessor chips and damage to the printed circuit board. For example, wide blue or purple stripes may occur after exposure to vibrations or shocks on the element base.

In this case, the soldering pads are damaged and the resistance of the contact groups changes. This problem is also diagnosed in the service center. Repair can be reduced both to heating the contact pads with a special air soldering station, and the complete replacement of the controller.

The malfunctions of the matrix decoders, and there may be several of them on the TV, are indicated black stripes. To eliminate them, you will also have to take the device to the service, since it is not possible to check the condition of complex electronics at home.

vertical stripes less exciting for the owner of the TV. They show a variety of failures in the matrix, not caused by serious damage to the hardware.

  1. A black bar may appear on the display due to a short-term power surge and a non-critical breakdown of the control keys. Usually the problem either resolves itself, or disappears after unplugging the TV from the outlet for 5-10 minutes.
  2. A lot of colored bars clearly indicate a problem with the loop. With some skills, you can check the status of this element yourself. As well as clean its contact pads and install in a regular place.

Important! Some problems with the TV screen can be diagnosed on your own. At the same time, it is worth remembering that all work must be carried out only when the device is powered off.

How to check TV yourself

You can get to the element base and TV boards only after removing the back panel. It is usually fastened with a group of self-tapping screws. All of them need to be found. Some of them on a device that has never been opened may be filled with a black compound, indistinguishable in color from the plastic of the back panel.

After all the screws are unscrewed, and the cover begins to move, do not rush to remove it. In some TV models, bundles of wires and even signal cables are attached to this part. Therefore, it is recommended to arm yourself with a flashlight and carefully check everything by slightly lifting the lid and examining what is under it.

After the insides of the TV are open to the eye, it is worth checking the following components.

  1. Large chips on the main motherboard. She is medium in size. There should be no cracks or discoloration of the case on the microcircuits.
  2. Chip legs and contact points. For inspection, you can pull the motherboard and other boards out of the latches and turn them over. The soldering should be continuous, without cracks and other alarming damage.
  3. Coils of the power supply board. They should not have excess dirt on them.
  4. plumes. They should not have creases, visible damage to the conductors. It will not be superfluous to pay attention to the places where these elements enter the connectors. There should be no dirt and traces of oxides.

All parts are then examined for signs of overheating. Usually this is indicated by changes in the color of the case. In places of abnormal temperature rise, yellowish spots form. It will not be superfluous to turn all the boards over and inspect the condition of their varnish surface. The resulting overheating also damages it and causes discoloration. capacitors are inspected. These are electrolytic cells in the form of barrels of different sizes. On their upper part there is a foil platform with a crosshair. When parts are damaged, their top clearly swells and becomes convex. The applied crosshair allows you to see this clearly. If such parts are found, it is recommended to replace them immediately, either by yourself or by contacting the service.

What can you fix yourself

Sometimes, to eliminate various bands and other TV failures, it is enough to clean it. In any work you need to follow simple rules.

  1. Wipe the structural elements, the matrix — you need only special means. A minimum of medical grade or pure isopropyl alcohol.
  2. Should work in rubber or clean thin cloth gloves. Left on the contact pads, the fatty secretions of the fingers become points of conduction disturbance and even oxidation.
  3. When disassembling and other actions, it is worth putting the TV on a flat soft surface with the matrix down.

dust cleaning done in an obvious and simple way: with a brush. It can be blown off using a vacuum cleaner or a rubber bulb. During cleaning, it is recommended to disconnect the connectors and carry out their maintenance.
Loops are turned off by pulling their ends out of the sockets as carefully as possible. The contact pads are wiped with alcohol, after which the elements are installed in their regular places.

Elimination of bad contact

Streaks on the LCD TV screen may appear due to poor contact connections. This kind of malfunction is usually the result of poor assembly or improper use of the TV. For example, the ingress of moisture into the case, which may be the result of improper cleaning of the screen, mechanical shocks. This reason can be established after a visual inspection of the connections with the naked eye or with the help of magnifying instruments.

Contact oxidation

Oxidation of contacts on the board

Contact oxidation you can clean it off with a blade or knife, it is easy to identify it by a green coating, but if the problem is large-scale, then it is difficult to fix it yourself. After that, you need to check the voltage or ring the contacts with a multimeter.

Poor contact can be caused by incorrect connection of the cables, for this they can be disconnected and connected again.

Another reason for the appearance of various bands on the TV display is cable wire break. It can be determined by lightly pressing or moving the cable: if the image is restored, then a breakdown has been detected. Elimination of a fracture is a painstaking and delicate process. It is necessary to determine with a magnifying glass exactly where the wiring is broken. You can restore them by using conductive varnish or by heating the contacts to a moderate temperature. Severe overheating will disable all contacts.

Conductive adhesive

Repair with conductive adhesive

Cable replacement

In some cases you will have to change the entire matrix loop on new. First of all, you need to purchase a new part — you can order it at a repair shop, but before that, find out the exact model of your TV, the year the TV or monitor was manufactured. You can change the faulty matrix cable yourself or in the service. When repairing, you will need a certain set of tools: screwdrivers or PH, PZ, TORX, HEX, SL bits.

The connection cable is located inside the case, therefore, it must be carefully disassembled. It is necessary to disconnect the roof, carefully unscrew all the bolts and get to the very part.

It’s important to know! The bolts are always standard and are unscrewed counterclockwise. In addition, many connecting cables and wires can be attached to the cover. When disassembling the TV, you should not make sudden movements, in order to avoid breaking.

Most connections are secured with special connectors, the wires do not have to be soldered. It is enough to press on the latch (the connection principle is similar to Internet or telephone cables).

The designs of TVs from different companies, such as Samsung (Samsung), Sony (Sony), Philips (Philips), may differ slightly, so you should use the instructions, or order assembly details on the official website of the company.

Damage to the matrix or its parts

This malfunction is characterized by the presence of a vertical strip of the same color with a width of one or two pixels. A defect occurs on its own and can also disappear within three to four days. If the problem lasts longer than a week, this is a clear sign of serious problems.

Replacing the matrix is ​​expensive and difficult, therefore, if there are such problems with the image, the solution will be to contact the service center if the warranty period has not expired. When the LCD TV has been used for a long time, repairs can be carried out by specialists from any workshop.

When repairing or replacing parts, keep the following in mind.

  1. Most conductors have a very small diameter and are easy to break.
  2. Repairing or resoldering contacts requires skills and special equipment (eg infrared soldering iron, magnifying glasses).
  3. All operations are carried out with great care, the wrong movement can result in additional breakdowns.

There are also simpler types of repairs. For example, black bars on the screen are often eliminated by setting up the TV, resetting it to factory settings, or switching to a different picture mode.

Advice! The best type of repair is prevention. By connecting your TV through an uninterruptible power supply or surge protector, you can significantly extend its life and protect yourself from various malfunctions in its operation.

Vertical stripes on a TV or monitor screen are caused by malfunctions, both minor and global. If stripes appear on the display, but there is no self-confidence, you should not find out on your own why a stripe could appear on the screen, it is better to contact qualified specialists. But if you have certain knowledge in electronics, then it is quite possible to repair a TV with your own hands. This also applies to other device failures. For example, it is quite possible to fix the remote control yourself. But if your TV has stopped turning on, then this may be a sign of a serious malfunction, which can only be determined with the help of special equipment.

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