What could be better than an evening watching a movie on TV? For many, this has become an ideal pastime, so it’s especially disappointing when your favorite equipment stops working properly. A white screen on a TV is a fairly common problem that requires immediate repair.
“Polite Service 5+” is a company that will help bring broken equipment back to life. Our team consists of exclusively professionals with extensive experience in repairing electrical appliances and electronics of any complexity. We work without breaks and days off from 7:00 to 23:00, so you can contact us at any convenient time. You can submit a request for TV repair by phone or on our website.
Causes of malfunction
It is impossible to independently diagnose what caused such a breakdown. You will need a master with professional equipment. The reasons for the appearance of a white screen when turning on or trying to change the channel differ for different types of TVs.
LCDs are characterized by:
- matrix malfunction;
- electronic defect;
- broken firmware;
- broken processor.
If a whitish screen appears on CRT television equipment, the faulty video amplifier is to blame. In plasma TVs, signal processing units are usually the first to suffer.
A separate category includes manufacturing defects, mechanical damage, moisture, or too long use. In some cases, it was possible to repair the electrical device by simply thoroughly washing the T-con board with alcohol, but this was rather a lucky coincidence. Repairs should be taken seriously and the help of professionals should not be neglected.
Manufacturers recognize defective batches of dies
Manufacturers for TV and monitors sometimes admit their mistakes and recall defective batches.
This happened in one store selling video equipment:
It turned out that during the production of the matrix on the conveyor, something went wrong and a defect was discovered in all the produced matrices (as they explained, when the matrix filters were superimposed on each other, the apparatus that did this had to heat the entire surface of the matrix plates, and in one point, the heating was slightly exaggerated, a gloss was formed INSIDE the matrix and, as a result, a stain during operation). Well, as expected, all the products were recalled, and those who managed to buy them got free. repair (replacement).
Another friend with such a stain decided to submit his laptop with a stain on the matrix for an independent examination.
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 the necessary 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.
LCD repair
The first thing to do for diagnosis is to check the source of the signal. This could be a cable box, player, etc. If, when you turn on the TV screen, there is nothing but a uniform white color, you need to press the MENU key on the remote control. You can press this button on the case, if there is one.
If there is a problem with the signal source, the control menu will open on the TV screen. If the device does not react in any way, it means that everything is in order with the set-top box or player, and the fault should be looked for in the equipment itself.
Experts say that in LCDs, in most cases, it is the matrix that is to blame. It rarely breaks just like that; often the breakdown is caused by moisture getting inside the case or mechanical damage. If the part is damaged, a complete replacement is necessary. Unfortunately, it won't be possible to fix it.
Reinstallation of the matrix occurs in stages:
- The body is disassembled.
- The broken matrix is pulled out, and at the same time the technician can fix minor damage in other parts of the electrical device.
- The new matrix is carefully installed in the right place.
- The part is connected to the loop and cable for testing.
- If everything is in order, the body is put back together.
It is important to remember that the matrix is very fragile, so installing it yourself without the appropriate skills is almost impossible. If even after installing a new spare part the equipment does not want to work normally, it is worth looking for the source of the malfunction elsewhere.
Another common cause of a white TV screen is a problem with the voltage supply. This situation can occur, for example, when VON and VOFF are interrupted. As a result, the electronics stop working normally and the screen turns white.
Sometimes the strange behavior of the monitor is due to damage to the electrolytic capacitors, which are located on the main board. In this case, when turned on, the monitor begins to glow with an even whitish light, but the image does not appear.
If there is no picture and the screen glows white, you should additionally check the firmware. If this is indeed the case, the software will need to be replaced.
If there are malfunctions in the work or the equipment has completely stopped functioning, you first need to find out the exact model. It is usually indicated on a small plate on the back cover of the case. This will allow you to choose the ideal firmware. Then you need to go to the official website of the manufacturer, for example, Samsung or LG. There you need to enter the model name and select the “Firmware” tab. The firmware is downloaded from the website, after which you can easily change the software.
Despite its apparent simplicity, you should entrust this issue to professionals. Since there is no image on the TV screen, it will not be possible to reflash it in the standard way through the menu. You will need a special programmer. If you try to change the firmware yourself, there is a high risk of making the wrong step and completely breaking the electronic “brain”.
Sometimes a white TV screen indicates a problem with the microprocessor. Typically, failure occurs due to overheating of the part. The technician first checks the processor for malfunctions, after which you can either replace the textolite or the spare part itself.
Setting up TV after fixing
Everything will depend on the processes that were done to fix the problem with the TV. Here is a list of some of them:
- If the decoder is replaced. There is no need to change anything. When replacing a faulty decoder with a TV tuner, you need to switch the source output for viewing channels and conduct an automatic channel search.
- If the backlight has been changed or the matrix has been replaced, check the brightness and contrast settings. They may need to be adjusted.
- If the set-top box has been replaced or repaired and reset to factory settings, you need to search for channels again. Auto search is the best option. Manual search takes longer, but will allow you to sort the found channels more thoroughly. All settings are made in the section: “Menu” – “Channels” – “Auto tuning”.
If you replace the cable or ports, you do not need to make any adjustments on the TV.
CRT TV repair
Such devices are gradually losing popularity, but, nevertheless, requests for their repair come frequently. If a CRT electrical device has no image, and the TV screen glows with a uniform white or green light, the video amplifier is to blame. You can check this by trying to increase or decrease the brightness. If there is no response, the video amplifier board will need to be adjusted. First of all, it is necessary to inspect the capacitors in the microcircuits and, if there is a malfunction, replace them with new ones. In severe cases, the entire video amplifier or picture tube will need to be replaced.
What you need to know before solving the problem
When a Samsung TV has sound but no picture, you should understand the specifics of how your TV works:
- The analog signal is supplied “as is”, while the digital signal is encoded into packet data, transmitted over a communication channel and decoded into audio and video. That is, if your TV works with digital channels, data loss will affect the operation of both signal and sound. Losing the video signal so that clear sound remains is basically impossible. Perhaps the problem lies in the transmission of the picture from the receiver to the TV itself.
- We need to determine what’s wrong with the screen?! It does not show, or does not work at all (that is, it is the same with any lighting in the “on” or “off” state).
Other causes of breakdowns
This category includes mechanical damage and moisture ingress into the housing. The matrix is especially sensitive to such incidents: it breaks down very quickly and will need to be replaced. When calling a technician, be sure to inform him if the equipment has been dropped or water has been spilled on it. This will help you quickly determine the location of the breakdown and make quality repairs.
If the TV is brand new and has been in use for less than a couple of months, there is reason to suspect a manufacturing defect. In this case, you need to contact the store where you purchased the equipment and replace it with a new one under warranty.
Sometimes the glow of a TV screen without a picture is explained by the fact that something inside has broken due to old age. If the device has served faithfully for several years, it is not surprising that the parts inside fail. You can try to repair it, but if the equipment is old enough, it is better to buy a new one.
“Polite Service 5+” accepts requests for repairs of breakdowns of any complexity. Our specialists will repair television equipment of any brand, reflash it, replace used parts and return normal settings. In order not to think about what to do with broken electrical equipment, you just need to call or fill out a form on the website.
Why does the kinescope glow white?
If the kinescope turns on and does not show, but there is sound, the settings will not affect anything. You will have to disassemble the device and look for defects. If you do not have experience, it is better to take the equipment to a trusted service center. Here are some common causes of picture tube problems:
- Defect in the light purity system. Cathode ray tube TVs combine color rays using a system of magnets. If the magnetic fields are knocked down, light will hit the screen uncontrollably. It is necessary to restore the magnetic positions on the neck.
- Modulator short circuit. In the event of such a breakdown, most often the monitor will be painted the same color as the cathode with which the modulator is connected, but sometimes a failure leads to a whitish glow. The short circuit needs to be repaired.
- Broken cathodes. This malfunction can only be diagnosed in a hospital, because the cause of the breakdown may also be hidden in the loss of emissions in the gun. In this case, it is almost impossible to restore the device.
- Power surge. This damage is universal for any equipment: with a sudden change in voltage, the contacts burn out, and a strong shock falls on the internal parts of the system. One of the nodes may burn out completely. It is necessary to disassemble the mechanism and replace defective parts.
- Moisture in the system. If the TV is placed near a wooden window or in a room with high humidity, over time water will condense inside the case and oxidize the parts.
- Wear of parts. Those who use CRT TVs have owned them for more than 10 years. During this time, some parts of the electrical circuit exhaust their service life. And if some defects can be eliminated by repair or spare parts, then damage to the beam tube indicates that the device will no longer be able to work. It will have to be replaced.
Do not try to fix the problem yourself. You will only make the problem worse. Use the services of experienced Remontano craftsmen. Call an engineer by phone or online.
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 author decisively managed to get rid of this problem after disassembling and washing the matrix layers: polarizers and diffuser. As far as I understand, the washing was done with water. It is unlikely that the water came from a tap, because it can leave a coating of salts and sediments that are immediately noticeable when held up to light. So it is better to rinse with purified water or highly purified alcohol.
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 on the air humidifier so that the air suspension settles and does not get between the layers of the matrix.
