LG TV has sound but no picture: reasons and repairs

Sometimes even high-quality equipment can fail. It is very unpleasant when the TV works, but like a radio. In some cases, you can make repairs on your own, but you may need the help of a specialist. First, you need to figure out why the LG TV has sound, but no picture. What are the reasons?

The most common causes of missing images on Korean LG TVs are:

• equipment broadcasts sound, but the image itself on the screen has disappeared;
• the screen is black;
• the backlight does not work;
• distortion of the image;
• dullness and dimness of the picture;
• periodic disappearance of the image or the screen goes blank;
• color reproduction in green tones or black and white.

The simplest thing that an average user can do is to conduct a visual inspection of the equipment. Within reasonable limits, it is even permissible to disassemble the TV and carry out its internal cleaning. How to independently detect breakdowns?

1. Discharge of capacitors by disconnecting equipment from the network.
2. Opening the back cover of the TV.
3. Inspect cables for possible kinks and breaks.
4. Inspect the power supply for swelling and melting of capacitors or resistors.
5. If you have special tools, you can measure the voltage of the input circuits of the power supply.
6. Gently tapping the TV case, you can understand the quality of the soldering of the modules and wires (if the technician reacts by blinking during manipulations).

If LG video equipment has sound, but there is no image or the picture jerks, then the problem lies in the breakdown of the power supply. You can independently carry out the following series of manipulations.

• Turn off the TV from the network. This will discharge the capacitors. Next, you need to unscrew the fixing bolts and remove the back cover. Check cables and cables for damage. It is also worth paying attention to the performance of the buttons and fuses.
• Inspect the power supply for melted or damaged resistors and capacitors.
• Measure the voltage of the output circuits of the power adapter. Indicators must correspond to those indicated in the instructions.
• Tap gently on the TV cabinet. In the case of the normalization of the operation of the equipment, it is worthwhile to carry out a complete diagnosis of the power supply. Poor adhesion may be the cause.

In this case, it is best to seek help from a master or the nearest service center, since improvised tools can aggravate the breakdown.

If the broadcast volume is normal and the screen is dark, then it is worth testing the antenna cable and HDMI cable. It may well be that the reason is the provider's unscrupulous work or the breakdown of the cable TV set-top box. The Moninfo utility will help you detect possible crashes.

You also need check the quality of the connection of the cable contacts and their integrity... To do this, it is recommended, with the TV turned off, to pull out and reinsert the plugs of the antenna wires and the electric cable into the connectors.If the problem lies in the quality of the HDMI cable connection or connecting wire, then it is enough to restart the set-top box or replace the docking cable.

Additionally you need pay attention to the router - is the indicator flashing (the connection to the Internet may have been interrupted). And if the cable connector itself is loose, then the replacement should be done as soon as possible. Damage to the cable insulation is extremely dangerous and fraught with the closure of the equipment contacts. In addition, the user may be injured.

This is perhaps the most common cause of breakage. In this case, the image can "jump", the picture can be only half of the screen, or the monitor "stripes" with all kinds of rainbow colors. The matrix tends to break due to moisture ingress, strong impact or when dropped... The component can also fail due to short circuits.

In this case, it is impossible to make repairs with your own hands. So, if the reason is mechanical damage to the matrix, then you will have to change it to a new one or purchase a new TV. Nevertheless, if the picture becomes "cloudy" or doubles, then the repair is carried out in the service center without replacing the part. With due experience, the matrix can be replaced independently. But the difficulty lies in the ability to find an original quality part. Otherwise, it is a waste of time and money.

Strong voltage surges in the network greatly affect the operation of capacitors. The main sign that the capacitor has broken is dimming display... Also, the transmission disappears immediately after switching on or after a short time the picture begins to double, the brightness may disappear.

If you disassemble the device itself, then you can see a swollen or exploded capacitor on the board. The fuse also blows out. By the way, after a power surge, the TV's power supply does not turn on first. In this situation, you need to contact to specially trained people... If the breakdown is not eliminated in time, the problem will become more complicated, as it will lead to a breakdown of the power supply.

Symptoms of malfunction of the matrix loop:

• the TV does not show an image, the picture periodically disappears;
• the appearance of ripples or interference in the broadcast;
• the display on the screen is distorted - stripes or duplication of the picture.

It will definitely require repairs in the technical center. The breakdown can be eliminated depending on the specifics of the loop damage. At an early stage, the detected malfunction is eliminated by re-soldering the damaged sections of the element. Otherwise, you will have to replace the part completely.

It is impossible to list all the signs of damage to an inverter. However, the most common are:

• flickering and distortion of the image;
• lack of video or its appearance with a delay;
• after turning on the equipment, the display loses its brightness or immediately goes out;
• the presence of broadcast sound accompanied by ripples on the screen;
• the picture is blurry or the picture is very dark.

The inverter is responsible for:

• the supply of electricity to the backlight lamps;
• conversion of 12 volts DC voltage to high voltage AC;
• stabilization of the input current of the lamp to the required value;
• backlight brightness control;
• matching the output stage of the inverter with the input resistance of the lamps;
• protection of electronic boards against short circuits and overloads in the power supply network.

Most often, problems in the inverter manifest themselves in lamps, transformers or controllers on the board.... To repair an inverter, you will need the ability to use a soldering iron, a multimeter and basic knowledge of physics and electronics.In other words, it will not be possible to make repairs with your own hands, and it will practically not be possible to carry out diagnostics. Only a master can help with the solution of the problem.

This is probably the most common reason for a missing picture on a TV screen. LG equipment often fails with LEDs in LED backlighting. It is not difficult to determine this.

Also, it is very easy to diagnose a backlight lamp breakdown. It is enough to turn on the TV in the darkest possible room and close the flashlight to shine into the monitor. An image should appear in the place of transmission.

Repairing such a malfunction at home is almost impossible. At a minimum, parts are ordered for a very long time directly from the manufacturer. Therefore, the best solution to the problem would be to contact certified service centers.

Such a breakdown manifests itself either immediately or gradually. The main signs are:

• color distortions or incorrect display of shades appear;
• one of the flowers disappears;
• the soundtrack is ahead of the transmission of the image, the screen glows in a blue tint.

In this situation, it is best to replace the processor with a new one.

The presence of wide stripes on the TV screen speaks precisely of the breakdown of the decoder. This can happen if the loop contacts are dysfunctional. Usually, this situation requires a complete replacement of the entire hardware internals of the equipment. In this case, it will be cheaper to buy a new device.

If the screen does not work, but the sound is present, it is better to do only the diagnostics of the equipment yourself. Namely:

• turn off the TV and turn it on again after a while - a normal system failure is possible;
• check the connection of the antenna cable and connectors, the wires could also break;
• increase the volume to the maximum, in most cases the technique will stabilize its work without further intervention;
• in case of regular voltage drops in the electrical network, it is recommended to install an uninterruptible power supply.

Only experienced craftsmen can repair modern TVs without damage, and the cost of parts for equipment is very high. That's why it is strongly recommended that you handle the equipment competently and carefully and correct the slightest problems in specialized organizations.

You will learn how to replace the matrix of an LG TV in the following video.