Repair the most common malfunctioning LG TVs

Any television receiver consists of several nodes interconnected with each other. Therefore, before you start repairing LG TVs or other brands, you can look at the image on the screen, even without disassembling the device, to determine the possible malfunction. Also, TVs can cause malfunctions, the cause of which can eliminate any home craftsman. These include simple problems: the power cord is faulty, the contacts in the electrical plug or the outlet went off, the batteries in the remote control were drained, and dirt accumulated under the remote buttons. But in other cases it is better to entrust the troubleshooting to professionals, for example, to repair the TV in the company of TV masters, whose specialists are engaged in the restoration of devices of all popular brands of any degree of complexity.

Typical malfunctions of LG LCD TVs

LG LCD TVs, like other brands of devices with similar technology, use an array of liquid crystals to display an image, which is illuminated by a lamp. The picture is formed by changing the optical conductivity (transparency) of the crystals. The matrix is ​​closely connected with the main modules of the device, therefore, if one of them begins to “mess up,” this immediately affects the image. It is for these symptoms and you can make a preliminary conclusion about the cause of failure.

Black screen, image completely missing

Several factors can cause this failure in LCD TVs.

1. The most common case is power supply failure. A visual inspection of all parts on the board, as well as the continuity of the transformers and the entire circuit will be required.
2. With an apparatus that works without an image, it may be suspected that broke the color block either a video amplifier.
3. The image may also disappear if the matrix itself is faulty. If a specialist determines that repair is impossible and a replacement is required, in most cases it is not profitable to change it from a financial point of view: the cost of the matrix is ​​comparable to the price of a new device. Of course, we are not talking about the situation when the TV is under warranty.

Dimming on the screen

The appearance of blackouts on large areas of the screen or on its edges indicates a malfunction that has arisen in highlighting system.

There are several reasons for blackout:

• burn-out of the backlight lamp installed in the matrix, which may occur due to a voltage jump or due to manufacturing faults of the lamp itself, which must be replaced;
• breakdown of a high-voltage converter, the operability of which can be quickly checked if it is connected to a working matrix;
• Inverter malfunction can also cause a blackout in the center of the screen;
• damage to the lamp in the fall or bending of the device.

On the snow screen

“Snow” image may due to poor tv signal. To check this, switch to another channel. If the “snow” appears only on one or a pair of channels, then this indicates problems with the TV signal, whose settings could be lost.

If interference is detected on all channels, then check antenna: cable connection and connection points, its integrity.

Also, ripples on the screen may appear when a faulty tuner.

Picture blinks

The blinking of the image can be caused either by overheating of the device or by a backlight, which has begun to “die”.

TV shows how a thermal imager

When an image resembling a picture from a thermal imager appears, reflash device memory.

Black spots on the screen

When the device is turned on, black small dots sometimes appear in the same places on the matrix. This fact indicates the presence of "broken" pixels, that is, liquid crystals that have lost their functions. There are no ways to eliminate this defect.

The appearance of large stains from a variety of non-working pixels can occur if the matrix is ​​damaged due to fluid entering it (water, juice, coffee, milk, etc.).

Since pixels cannot be restored, the matrix will need to be replaced.

Horizontal stripes

Most often, the problem is solved after checking the power supply, where they are detected swollen capacitors. If everything is in order with it, it means that it is necessary to check the submodule board.

Vertical and horizontal stripes

This failure can signal that you need a fairly expensive repair, if it turns out that LCD matrix controller burned outor a closure occurred in it.

In addition, bands may appear for the following reasons:

• the cable is loose; the video connector is clogged;
• wrong settings - it is necessary to start the device auto-tuning;
• if the stripes are narrow, this may indicate a problem with the matrix;
• T-controller failure - the board must be replaced.

If horizontal or vertical stripes appear on the screen that do not glow (black), then there may be a fault in the decoder of the rows and columns of the matrix. Often a similar situation occurs after being struck by lightning or a power surge in the power grid. Over time, the band will increase and eventually close the entire screen. In most cases, the matrix must be replaced.

The screen glows, but no pictures

The lack of an image with a white screen indicates that you need to check the capacitors on the power supply. But most often faulty capacitors that require replacement are found on the motherboard.

Screen flicker

When you turn on the TV receiver, the screen starts to flicker, the image appears and then disappears, broad bands skip, etc. But if you lightly tap on the side of the TV, then for a moment the picture becomes normal. This behavior of the matrix is ​​due to poor contact between the cable and the matrix connectorto which it is connected. To fix the problem, you will need to disassemble the TV, and it is better if the master does it in a service center or at home.

Wide vertical stripes

The occurrence of a wide vertical strip indicates the failure of the matrix or the appearance of faults on the T-KON board.

Also, a bar appears if the loop of the matrix departs.

There is sound, but there is no image

This problem often occurs on the LG47lm640t TV due to bad contact plume matrix.

Before contacting experts, check the settings of the device: perhaps the brightness was accidentally reduced on the remote control.

In addition, the image may disappear if:

• faulty LED driver that converts power to the matrix LEDs;
• There was an open circuit backlight;
• there are malfunctions in the motherboard;
• there was a failure in program management.

Diagnosis and elimination of the above problems is possible only in the service center.

Frequent malfunctions of LG Plasma TVs

The screen of the plasma TV is arranged differently than the matrix of the LCD device. Instead of liquid crystals, there are a lot of capsules (cells) in it, which are filled with a special gas. These cells are coated with a phosphor of different colors (red, green and blue). When current is applied to the capsule, a plasma is produced from the gas inside it. As a result, the cell starts to glow, and its color depends on the applied coating.

The most common plasma breakdown is phosphor burnout.. To extend the life of this coating, you must comply with the manufacturer's recommendations for the operation of the equipment:

• do not place the TV in direct sunlight;
• a static image should not be allowed on the screen for a long time.

Also a common problem for LG plasma TVs is software failure. The problem is solved, as in the case of LCD devices, by flashing the device software in the service center.

Various image defects, such as incorrect display of colors, the appearance of stripes, the absence of a picture full or partial, as in the case of LCD panels, is solved by checking and repairing the motherboard, as well as other components of the device.

Such actions can be performed only by highly qualified specialists, if you do not want to lose expensive equipment due to illiterate repair.