Bad weather can cause damage to household electrical appliances.
During a thunderstorm, it is not recommended to turn on the television receiver; it is best to completely disconnect the device from the network.
Otherwise, there is a high probability that the microcircuit may burn out and will need to be restored. The TV backlight lamp has burned out - contact TeleMaster.
Manifestation of a malfunction - how to identify a broken TV unit
Whatever the breakdown of the power supply, it will certainly affect the operation of the TV. Damage to this element is primarily indicated by the following signs:
- The TV does not turn on;
- the indicator light does not light;
- You can hear the whistling of the pulse transformer, while the TV does not work because the power supply protection device is activated (this may also be a sign of failure of the LED backlight).
When the TV is turned on normally and various abnormalities in sound or image appear, these disturbances are most likely caused by some other reason, and not by a breakdown of the power supply. At the same time, there are some exceptions to this rule when the problem that arises is in one way or another connected specifically with the power supply:
- the indicator lights up, but the TV does not start in operating mode;
- when you press the power button on the device itself, the TV does not start;
- At first only sound appears and only after some time does the image appear;
- normal picture display and sound playback appear only after the TV is turned on and off repeatedly;
- the appearance of stripes, background sound, and a broken image are observed.
Why you should entrust the solution to your problem to our specialists
How Remontano service specialists work:
- We work with TVs from all manufacturers (Sony, Daewoo, Samsung, LG, Toshiba, JVC), regardless of the type of product and year of manufacture.
- We quickly and accurately determine the source of the problem and offer the client the best way to solve it.
- We use only original components.
- We repair equipment at home within one to two hours, without taking the equipment to the workshop.
- We guarantee low prices for services and a high level of quality of work performed.
Experienced service engineers who know exactly how to correct color problems on a TV of any type and model will work to solve your problem.
Main causes of failure
Power supply failure in modern LED TVs is one of the most common problems. Damage can be caused by many factors, but experts identify 4 main reasons:
- Voltage drops in the network (receipt of greatly reduced or increased output voltage). As a result of constantly fluctuating voltage, not only the operation of the TV deteriorates, but also the components become unusable. To avoid problems due to unstable voltage, it is recommended to use a stabilizer.
- Short circuit . It can lead to burnout of many components and parts of the device, including the power supply.
- Failure of the mains fuse . A burnt-out element will first be reported by the standby indicator - it will not light up.
- Damage to capacitors . A frequently occurring problem, especially when using the TV for a long time. The wear of the capacitor is influenced more by temporary than external factors. The failure of this element can be recognized through visual diagnostics by its characteristic swelling (bulge).
The occurrence of power supply malfunctions is also facilitated by:
- non-compliance with operating recommendations;
- violation of the climate regime;
- disassembling the device without experience and knowledge of the equipment.
The TV does not tolerate sudden changes in temperature and humidity. Having bought it in winter and brought it into a heated room, do not turn on the device immediately to avoid the formation of condensation inside and premature damage to important components.
To repair expensive equipment yourself, you need to have basic technical skills and special tools. If all this is missing, it is better to immediately contact the workshop.
Blue screen on LG TV: what to do
What to do if the TV shows everything in blue. Let's look at the most common causes of this problem.
In the digital age, television has become an integral part of life and is found in almost every home. Over time, like any other household appliance, an LG TV can break down. Malfunctions can be of different types, some can be fixed on your own, while others should be addressed to an LG service center.
Consider the situation when an LG TV shows a blue screen, what to do about it, how to fix it:
- First of all, try turning off and disconnecting the TV from the power source for 10-15 minutes; a software failure may have occurred due to power surges.
- Try disconnecting and reconnecting the antenna; the cable may be loose and causing signal loss. Or there was a glitch on the cable TV provider's side.
- Check and adjust brightness settings.
If none of the methods brings results and the blue screen on the LG TV does not disappear, most likely the LED in the backlight has failed. You can deal with the problem only by contacting an LG service center.
If we took a previous generation TV model, when they used a kinescope, then such a problem would not arise. But these models do not support modern digital technologies and are inferior in screen clarity and resolution. In addition, they are large in size and weight.
To understand why the LG TV screen turned blue and why you can’t solve the problem yourself, let’s look at how the backlight works. Modern televisions are devices whose screen is built on a liquid crystal matrix backlit by LEDs. As everyone knows, there are no diodes that emit white light. There are LEDs in almost every color of the rainbow: red, blue, green. But white people don’t.
There are several ways to get around this limitation. One is the use of RGB triads. This is when the housing of one LED contains three different colors at once: red, blue and green. But this technology is expensive and generates high heat.
The second method is to use a phosphor. A phosphor is applied to the blue diode, the blue glow falls on the phosphor layer and the phosphor makes it glow in the desired color - white. White color can be cold, or it can be warm. LEDs of this type are used in the backlights of modern TVs.
Current flows through the backlight LEDs and after a while the LEDs may fail. The reason for this is high temperature. A high temperature level can destroy the housing of the LEDs, and can damage the phosphor layer, this is the main reason why the TV screen turned blue. There is only one way to solve the problem, to make the blue color recede, and that is to replace all LEDs or individual LED strips. But only a specialist can diagnose and assess the scale of the problem. Therefore, if a malfunction occurs, immediately contact an LG service center.
Diagnosis of the TV power supply before repair
To perform a competent diagnosis of a power supply failure, you need to carry out several step-by-step actions.
Disassembling the TV
Determining the cause of the problem begins with disassembling the device. To do this, unscrew the screws from the back cover of the TV to open access to the power side.
In different TV models, power supplies are located differently, so it is not always possible to immediately see this element after removing the cover. If this is your case, then access to the power supply is most likely blocked by a protective metal casing.
In some TV models, additional protection may be installed specifically for the power supply. In this regard, you will have to go through several stages of unscrewing the screws that secure the desired part.
Familiarization with the power supply device
To take further actions, you need to clearly understand what the components of the TV power supply look like. All modern models have not one power supply, but several. They are usually located in one place - the board. This board is easy to distinguish from others: in addition to capacitors and other components, it contains 3 black and yellow transformers.
The TV power supply consists of the following components:
- Standby power supply . Its main function is to keep the TV in standby mode and await subsequent commands. A glowing LED indicator indicates that you are in this mode. For normal operation there must be a voltage of 5V, the supply of which to the TV is provided by the duty element.
- Inverter block . The main function is to provide power to the processor. If this function is violated, when you try to turn on the TV, an instant transition to sleep mode is observed. This occurs as a result of the fact that the processor, without receiving confirmation of functionality from the inverter, stops activating further actions and returns to standby mode.
- PFC block . The main task of this component is to correct the power factor, which can be reactive or active. The first is necessary for the operation of the TV, at the same time it can significantly increase electricity consumption and affects the rapid wear of capacitors, which negatively affects the service life of the power supply as a whole. Active power carries out a useful action, and reactive power only transfers to the load from the generator and again to the generator.
Important information about power supplies:
The structure of the TV power supply and its main components is described in this video:
Troubleshooting
After familiarizing yourself with the components of the device, proceed to diagnose it. Using a tester, ring the output of the standby power supply - the result should be 5V. If the voltage is less than this indicator or is completely absent, the problem is most likely failed capacitors. To determine this, a simple inspection of these parts is enough - they will be convex.
The most vulnerable components of TV power supplies include filter capacitors, which lose their nominal properties faster than others. However, the damaged element does not always have visible damage. Poor-quality filtering leads to inoperability of the power supply, failure of the inverter, and software failures of the microcircuits on the board.
If the capacitors are OK, check the fuse. For this purpose, a ring is used, which will reveal the presence or absence of a short circuit.
You should also test the board from the back side, for which you must first remove the element from the frame. Check the resistors for the following deviations:
- darkening;
- cracks;
- poor soldering of leads;
- gaps between tracks.
All this can be tested visually, and then a decision can be made on how to solve the problem. If the inspection shows nothing, check the resistors with a multimeter. A fault will be indicated by zero resistance.
Why did the screen turn green?
If the TV shows green, it is difficult to determine the fault yourself:
- Transistor failure. The green video amplifier breaks through, as a result of which the screen is painted in one tone, only the shades change.
- The cathode is closed with the modulator.
- There is a capacitor leak.
- Emission lost.
Yellow-green shades appear as a result of incorrect settings or a damaged microcircuit .
Step-by-step instructions for repairing a TV power supply
Power supplies for modern TVs usually have a standard circuit. The existing differences boil down only to the size of the electronic elements and output power. In this regard, diagnostics and repairs occur using the same method.
Typical power supply circuit for a foreign TV:
Required tools and materials
For repairs, you should stock up on tools and materials, without which it will not be possible to properly fix the problem:
- soldering iron with adjustable power;
- solder, alcohol (refined gasoline), flux;
- melted solder remover;
- screwdrivers included;
- nippers (side cutters);
- tweezers;
- tester (multimeter);
- lamp 100 watt.
When starting to repair a TV power supply, you need to have a schematic diagram of the model on hand (if you don’t have one, you can download it online from the manufacturer’s official website).
