LG TV has a dark spot in the corner of the screen. Manufacturers recognize defective batches of dies. Debris between the layers of the LCD matrix
Depending on the nature of the damage to the TV screen, stripes of various types may appear on it. Some appear after wiping the TV with a damp cloth, some after an impact, some on their own. Let's figure out what's what with these stripes and how much it might cost to repair your TV if stripes appear on the screen. Go!
- One or more vertical stripes
Such stripes appear either as a result of prolonged use of the TV, or after unsuccessful cleaning of the screen (wiped with a wet cloth).
This image defect is caused by wear and tear on the signal cables that connect the matrix glass and the matrix control board.
Less commonly, such a defect appears when the T-CON board malfunctions; this is easy to fix and costs about 2-5 thousand rubles, depending on the TV model.
In most cases, repairing this defect is impossible without replacing the matrix, and accordingly, you will either have to put up with it, or it’s time to think about buying a new TV, and your device because. Replacing the screen on a TV is often impractical due to its high cost.
- The image is split in half (only half the screen is shown)
This malfunction is most likely caused by a malfunction of the picture control board (T-CON), or damage to the cables going from this board to the TV matrix.
Since cables are quite versatile and inexpensive, you can restore a TV from this condition without any problems.
Very often, such a breakdown occurs when long bolts are screwed into the back panel of the TV at the place where the stand is attached, as well as when moisture gets on the TV.
- There are many multi-colored stripes, the image on the TV is not visible, the sound is
The range of problems here is quite large - the LCD matrix of the TV, the motherboard (MAIN) or T-CON may be faulty.
Some problems can be fixed for a small amount - from 2 to 4 thousand rubles, and in the case of repairing the matrix or replacing the TV motherboard, the repair amount increases significantly.
Spots can be different - such white ones as above can cause wear and tear on the screen backlight. TV backlight repair described .
Spots like the one in the picture below indicate damage to the matrix and you will need to replace it. Replacing the screen may not be practical. More details have been written about her.
If stripes appear on your TV screen, we advise you to contact the service center as soon as possible. If the problem is not corrected in time, the streaks may increase.
Hello everyone! Today I will share my thoughts on what to do if stains appear on the screen of a TV, monitor, laptop or tablet. Over the past few years, Samsung has been a leader in the production of matrices for TVs, monitors, laptops, tablets and smartphones. There was news that even Apple installed a matrix from Samsung in its new IPhone. As we understand, the South Korean manufacturer is inexorably increasing its turnover in the number of matrices per year. However, as is known, an increase in quantity often occurs at the expense of a decrease in quality. As a result, the Internet is full of messages and questions from users about stains on the screen of a TV or other display device. Often such messages refer to Samsung matrices.
Stains on the TV screen from impact
In this article we will consider not only spots related to the reliability and build quality of the matrix. Stains from impacts on the matrix in the hearts or accidentally left for the next advice - replace the matrix. Why? Because the thin structure of the matrix is almost impossible to repair. It is easier and cheaper to make a new display than to restore the old one. Here are examples of spots that appear after hitting.
Stains from impacts on the screen most often have clear boundaries and traces of cracks. Over time, blurry contours may appear as neighboring pixels begin to break due to heat and internal stress.
Gray spots on a white background on the matrix
Now let's talk about spots on the screen that look like dark spots or bright spots on a white background. I’ll give you a few photos found online showing these spots on the TV screen in all their glory.
Here, apparently, we are talking about a violation of the flatness of the polarizer or diffuser located in the layers of the matrix.
In the next photo you will see the result of installing a defective diffuser or reflector. Moreover, most often such defects do not appear immediately after purchasing the monitor, but over time, due to heating, the geometry of the layer is disrupted.
This is approximately what the matrix structure of an LCD TV looks like.
It can be seen that the matrix is multilayer and has a strict order of layers and their orientation. So when disassembling and assembling LCD displays, you need to observe the order and orientation of the layers.
Next we see the result of microdust getting between the layers of the matrix. This happens when the screen layers around the perimeter are poorly protected. When an LCD monitor or TV heats up and cools down, air moves between the layers of the matrix - this creates a kind of pump that can suck in such an unpleasant amount of dust in a few months.
To be honest, such shortcomings in the design of screens are not surprising. All manufacturers are trying to reduce their costs and reduce the cost of the materials and designs used, which leads to such “childhood” display diseases.
I even found a video that also shows heterogeneous spots on the TV screen.
In principle, dust between the layers of the matrix is possible, but this must be done carefully so as not to make the matrix worse. One awkward movement - a jam or a scratch - will not be corrected in any way, but will be very visible in the image.
Manufacturers recognize defective batches of dies
Test result: the cause of the identified defect is a defect in the liquid crystal polarizing filter.
Conclusion: this drawback arose due to the use of low-quality components by the laptop manufacturer that do not provide necessary resource MTBF within the period of its normal operation.
the cost of the examination is 6,200 rubles, the period of implementation under the contract is 30 calendar days.
A person with this conclusion went to the warranty service with the intention of going to court in case of refusal of warranty repairs. How it ended is unknown.
Liquid stains inside the matrix
It is also worth distinguishing between dust stains and liquid stains inside the matrix. Here is a photo of an example of such a stain after pouring alcohol on a laptop.
The main feature when repairing such matrices is to work with gloves and the absence of dust in the room.
From my own experience, I will say that disassembling a TV screen, monitor or laptop is best done in a clean room after a thorough wet cleaning. To settle the dust, I additionally eliminate the draft in advance and turn it on so that the air suspension settles and does not get between the layers of the matrix.
Dark semicircular spots around the perimeter of the screen
Remember that not all stains on the TV screen are equally incurable. Here is an example of dark spots that are caused by part failure.
Most often, such spots appear on monitors and televisions from cheap manufacturers and frankly Chinese companies. It’s good that such matrix malfunctions can be easily fixed by replacing the LEDs in the backlight with new ones. Sometimes simple contacts help.
Debris between the layers of the LCD matrix
It happens that at the factory or during transportation, dust particles or other debris end up inside the matrix between the layers.
This happened with a new TV and this is what Samsung technical support responded, according to a participant:
This is what SAMSUNG responded to me:
Hello.
The Technical Department reviewed your request and reported the following:
The display housing has ventilation holes to allow heat to escape from the display backlight elements. Through these holes, insects could get inside the display. This is a TV production technology, like that of any other equipment manufacturer, to ensure the outflow of heat from the display backlight elements. The manufacturer is not responsible for insects getting into the equipment.
Here is a method I found from one of the IXBT forum participants:
You need to take a soft cloth, such as a scarf or sweater sleeve, and lightly hit it on the screen, next to the speck of dust. Dust particles are knocked out, and the risk of damage to the monitor is low. I hit the particularly stubborn ones a little harder - this left faint temporary traces on the matrix, which disappeared after a couple of minutes. The result is that the screen is clean, the monitor is intact and serves its owner well.
And in the same forum thread, people also advised tapping on the sides of the monitor - it also helps to push a speck of dust down, when the layers seem to separate for a moment.
How to get rid of stains on the matrix
So, let’s summarize and explain how to get rid of stains on the matrix and what cases are covered by the guarantee:
- Stains on the TV screen from impacts cannot be repaired in any way (the case is not covered by warranty);
- If the matrix has leaked, then nothing can be done (if there are no signs of impact, you can try to return it under warranty);
- If dust gets into the matrix, you can wash the layers of the matrix and dry it without scratching it (dust ingress is a violation of operating conditions - a non-warranty case, but sometimes people are lucky and are replaced under warranty if the batch is defective);
- If the screen is filled with liquid, then there is a chance to wash the layers yourself (the case is not guaranteed);
- If part of the backlight fails, replace individual LEDs or the entire line at once (warranty case if there are no signs of tampering).
LG TV: a bright glowing spot appeared in the upper right corner, as if a switched-on chandelier was being reflected. What could it be? Do I need to repair it and how expensive is it? Faith
Expert's answer
Hello, Vera!
It is not indicated what type of screen the TV has, but we can assume that it is an old type - cathode ray or, as they say, a kinescope. The fact is that screens of this type are susceptible to extraneous magnetic fields and mechanical influences.
To eliminate the influence of magnetic fields, televisions of this type are provided with a demagnetization loop, which consists of several turns of wire along the circuit of the kinescope, connected through a thermistor. Every time the TV is turned on, the demagnetization loop receives mains voltage. Further, due to heating of the thermistor, the current through the loop decreases to a minimum value. If the magnetization of the kinescope shadow mask has great importance, then one demagnetization cycle is not enough. You need to turn on the TV several times over an interval of 15–20 minutes (you need to give the thermistor time to cool down).
If this method does not bring results, then most likely the thermistor has failed. The demagnetization loop fails extremely rarely, since its wire cross-section is chosen with a large margin. Checking the loop resistance with an ohmmeter should show several tens of ohms.
A faulty thermistor can usually be identified by its collapsed housing. To replace, it is not necessary to install exactly the same one. You can take it from another TV model. The main condition is the correspondence of the location of the pins and the geometric dimensions.
Due to strong blows The shadow mask may become dislodged or deformed. In this case, restoring normal operation is impossible; only replacing the kinescope is required.