Why the TV may not catch digital channels and how to fix it. Seven reasons why digital TV does not work and how to fix it Why TV does not work
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Despite the widespread use of the Internet and "smart" gadgets, television still occupies a large place in the lives of most residents. When the unit breaks down, users most often turn to specialists, but there are problems that you can deal with on your own. To understand why TV began to show poorly, you need to understand the features of the operation of modern devices and the likely causes of malfunctions.
The principle of operation of a modern TV
If there is no image on the screen, while the device transmits sound, most likely the malfunction is related to the picture formation circuits. If earlier the technique functioned with the help of a ray tube, where close attention was paid to the posistor, then modern devices work with the obligatory use of backlighting. This parameter mainly determines the price of copies.
Illumination is carried out using various means:
- Halogen lamps covering part of the monitor or the entire perimeter;
- Organic diodes, which increase the cost of products;
- Lamps for ignition, combustion, which require a discharge from high voltage.
The inverter starts the transformer, it avoids dissipation of the output current. After the power reaches the dimmer, the signal travels through the circuit, generating current, after which the backlight lights up.
Why is the TV not showing
All possible problems that affect the lack of a picture or its poor quality are conditionally divided into two categories - related to hardware and related to software settings. The first category includes problems associated with the breakdown of the unit itself or its parts.
Broken
If the device was working properly, then suddenly there was a click and the screen went blank, the likely cause is a power surge. In this case, the protective relay is activated and knocks out the fuse located in the power supply.
The screen may suddenly turn off from a power surge
At best, a black screen will appear for only a few seconds, after which the instrument will resume operation. More unpleasant consequences include the following symptoms:
- the smell of burning;
- smoke from the hull;
- the presence of sparks;
- ignition.
Burnt out backlight
In the absence of a picture, but the presence of sound, the cause of the breakdown is a burned-out inverter or the combustion lamps themselves.
inverter
The element is responsible for the movement of current from the power supply to lamps or LEDs. Thanks to him, the monitor is illuminated and the image displayed on the liquid crystal matrix is perceived by the eyes.
Inverter switching circuit
To check the health of the inverter, you should make sure that the fuse is intact and measure the input voltage, it should be 12 V. If everything is in order outside, then the problem lies inside the device. You need to check the power on the dimmer circuit. If a breakdown is detected, the burnt part must be replaced with a new one.
backlight lamps
A typical malfunction for Chinese technology, such as Supra, Xiaomi, Fusion, Mystery and others. It is revealed very simply: you need to shine a flashlight into the black display. If there are any changes on the monitor, which indicates a change in pictures, the inverter or lamps are to blame. If no movement is observed, then the liquid crystal screen itself has broken. The first option is simply resolved by replacing the failed element, while in the second case everything is much more complicated and expensive.
Broken LCD screen
Not the most popular cause of a malfunction, which is easier to prevent than to fix later. A signal indicating the need for urgent repair or delivery of the unit under warranty is one of the following symptoms:
Important! If any of the described problems occurs, you should immediately contact the service center, otherwise the monitor will fail, and its repair will be very expensive, which is not always justified. Why the TV does not show: channel tuning algorithm
Most often, the device does not show well due to the fact that the channel settings are incorrectly performed or knocked down. The procedure for resolving the situation depends on the signal source used, but in general, frequency tuning is carried out according to a single algorithm. First of all, the antenna or other communication source must match the signal of the TV tower. Having caught a suitable signal, the adapter displays it on the device. After connecting to the receiver, the channels are configured as follows:
Attention! If some channels are not installed or recorded twice in a row, you can perform manual tuning. There are prompts on the instrument. The most important thing is to connect the receiver correctly. Antenna
For a long time, television broadcasting was carried out through analog antennas, and now digital television is gaining more and more popularity. Regardless of the source used, the following series of checks should be carried out first:
- Make sure that the plug is securely connected to the connector;
- Check the cable for integrity and the absence of damage: if a kink or a frayed, gnawed area is found, it is enough to replace the damaged segment with a new one;
- Determine if the antenna is in place, if there are any signs of rust or mechanical stress on it;
- Try to twist the antenna itself and the place of its connection with the TV.
analog
The analog signal is characterized by the following problems:
- the appearance of a black and white picture;
- deterioration in quality, the appearance of ripples;
- lack of clarity;
- blurred image;
- transmission interference.
If before that there were no problems during viewing, and then the symptoms described above began to occur, you should check the serviceability of the antenna, cable and the accuracy of the connections. If no manipulations helped, most likely the equipment is out of order and you should contact the service center.
Digital
The presence of a digital antenna at home is indicated by the presence of a small black box. With this source, watching TV channels is free. The equipment may periodically issue the following violations:
There are situations when it is not possible to set channels on a new device. This may be due to two reasons:
- the antenna is chosen incorrectly;
- the receiver is incorrectly installed, more precisely, the direction vector does not match the location of the broadcasting station.
Most of the answers to your questions should be found in the user manual. If all else fails to resolve the situation, you should try the following steps:
- When entering settings, put a dash in the country selection field;
- Add channel frequencies manually;
- Update software;
- Reset to factory settings and start the process over;
- Check the performance of the receiver on another unit;
- Update firmware.
Satellite television
Most often installed in remote areas where there is no access to the antenna signal.
Satellite signal transmission scheme
If TV channels do not show or a black screen occurs, you need to act depending on various factors:
- In case of wind, rain, snow, storm and other weather disasters - wait until the weather returns to normal, then the signal should return;
- In the presence of dirt, cobwebs or wet residues - carefully wipe the plate without changing its position;
- Violation of the integrity of the wire, the accuracy of the connection - it is enough to inspect the receiver and cable to make sure that the connection is correct;
- The annual subscription for access to television broadcasting has ended - you need to make payment for the next period;
- The Tricolor-TV card has departed, resembling an ordinary SIM card - just push the part all the way.
Digital
If TV channels are broadcast not through a separate digital antenna, but by connecting to an Internet provider, in case of a malfunction, you need to call technical support. Most often, a signal failure is due to failures on the part of the service provider. You will need to check if there are any problems when transmitting large amounts of information, which is usually observed with video broadcasts.
Failures in digital television most often occur through the fault of the provider
Healthy! It happens that problems with broadcasting channels are associated with incorrect cable connection. You need to check that the plugs match the connectors. Sometimes the problem arises because the technique is outdated for modern sources. In such a situation, you only need to change the old unit to a new one.
Conclusion
Even with the advent of advanced technologies, not all problems associated with the reception of television communications can be resolved. If the TV began to show poorly, there can be a lot of reasons for the malfunction, which makes it difficult to find the problem and solve it.
First of all, you need to make sure that the receiver is properly connected to the device, there are no mechanical damages. Before proceeding to check the health of the equipment itself, it is first worth checking the correctness of the settings made. It will be useful to make sure that the reason does not lie in the absence of a signal from the supplier or is not related to adverse weather conditions.
It is worth resorting to the help of specialists as a last resort, most problems can be fixed on your own. At the same time, it is necessary to carefully monitor the quality of the transmitted image, it is better not to delay the diagnosis and possible repairs. This will avoid significant costs for expensive repairs or the purchase of new equipment.
Watch a video on what to do if your TV has sound but no picture
Most of the country's territory is already covered by digital terrestrial TV broadcasting, broadcasting is stable, but sometimes there are blackouts. This article is not only about why digital television does not work, although before that everything was in order, but about all cases of problems with it.
When you turn on the set-top box for the first time, you are prompted to search for digital channels, but the set-top box does not find any channels. There were cases of changing the order of the channels, this also leads to the need to reconfigure the set-top box or TV, but the most common cases are when the set-top box showed yesterday, but not today.
Reasons why they stopped catching digital channels
Problems for which digital television does not show can be divided into 3 categories:
- termination of the broadcast;
- weather;
- equipment malfunction.
Broadcast termination
When carrying out maintenance work on the site rtrs.ru in your region, you can find information about the time of their implementation, while the screen usually displays a setting table.
If the set-top box catches only 10 channels, although before that there was broadcasting and 2 packages, then you need to check the signal level on one of the channels. If it is 0, then it is most likely disabled. This is usually due to the fact that it was broadcast in test mode. After the equipment has been tested and information has been collected, the broadcast is turned off.
Package 1, as already noted, is already being broadcast over most of the country and it is mandatory, unlike package 2. Difficulties with the introduction of package 2 are associated with analogue television broadcasting, as there are not enough free frequencies.
The cessation of analogue television broadcasting in 2018 will speed up the inclusion of 2 multiplexes.
Of course, an emergency shutdown of broadcasting due to a malfunction is also possible, but this is unlikely.
Weather
Those who have already dealt with satellite equipment know that in heavy rain, and especially when snow sticks to the “plate”, the image crumbles into squares or disappears completely. This also applies to why digital television does not show well in bad weather. Why doesn't digital TV show today.
You can identify this by checking (see above), in this case the signal will be greater than zero, but small for high-quality reproduction.
There is only one way to deal with this - it is to increase the signal as close as possible to 100%, then any bad weather will be nothing.
Hardware failure
If digital television does not work completely, then here you need to divide it into, then what exactly is the problem that something does not work. It could be:
- device malfunction;
- cable and connections failure;
- antenna failure.
Attachment not working
There is probably no point in dwelling in particular detail on this point, since the malfunction of the set-top box will be immediately visible in this case. When the set-top box is turned on, the LED signaling that it is turned on will not light up, or it will glow dimly.
Many consoles have a separate 5 volt power supply. It is usually standard and suitable for many devices (for example, a router) and you can check the serviceability by a simple replacement.
Checking the output voltage with a multimeter may not give anything, since in the absence of a load, the measurement can show the prescribed 5 volts.
The set-top box is constantly rebooting or the splash screen is simply shown, and the execution of commands from the remote control or panel does not occur.
Cable and connection failure
In this case, more than one channel does not work, as the signal will be lost. Look carefully at all connections and not the integrity of the cable. This is especially true for RG-6 (white) for interior work, which we sell everywhere. Its service life on the street is short, it cracks, water gets into the cable and the braid is destroyed.
Antenna failure
Indoor antennas rarely break, but outdoor ones often enough. Rarely from moisture, but from thunderstorms quite often. How many do not reconfigure the digital set-top box does not find channels. What to do in this case? In order;
- start by checking the cable and plugs;
- check the voltage supply from the set-top box or from the power supply;
- connect another antenna.
Let me remind you if the antenna does not catch digital channels, then check its direction to the transmitting tower.
No digital reception on TV
All of the above is also suitable if the TV does not catch digital channels. In TVs, as in set-top boxes, tuners with different sensitivities are installed. Therefore, it is possible that some TVs work normally from the antenna, while others from it are unstable.
In this article, we will talk about the problems that lead to the TV not showing channels or the TV not working.
Below we will consider ways to solve problems with TV, which are divided into 2 parts - when the TV does not work at all in the literal sense (it does not start, etc.) and when there are simply no channels, i.e. TV as a device works (gives life signals), but there are no channels.
TV does not turn on
If your TV does not start at all, then this can already indicate very serious problems with it, in which you often need to contact a service center for the help of specialists, but we will not bury your TV ahead of time and make sure what is wrong with it.
1. Check that the power cable is connected to the outlet and there is electricity in the outlet.
(Children can play and accidentally pull out the cable).
2. If you are trying to turn on the TV using the remote control, make sure the batteries are not dead, and the signal receiving surface is not obstructed and in direct line with the remote control.
Usually a small light is on on the TV, indicating that the TV is working properly, just turned off. If it is lit, but the TV remote control does not turn on, then something is wrong with the remote control.
3. It may turn on, but a black screen appears on the TV. This indicates that you "clicked" something on the remote the day before and turned on that mode or went there in the software interface, where the screen is black. Try clicking on the channels and try to do something different.
4. Perhaps the day before there was a thunderstorm, which is a very common reason for the failure of both TVs and other household electrical appliances. If this is true, then your TV will have to be transported by specialists.
No TV channels
Let's take a look at situations where the TV actually turns on, but the channels do not show as such. If your TV is "alive", but there are simply no channels, then you are in the material below.
Remember! If you have satellite or digital TV, you must use the remote control of the receiver / receiver, not the TV, to select channels. And before that, the TV with its own remote control must be switched to AV mode or the one where your TV is connected.
There are quite a lot of materials about what and how to do when the channels do not work, so we have made separate articles about this.
If you have a regular old antenna, then you need to search for channels on the TV using the appropriate function in the TV MENU.
If you have any questions regarding the operation of the TV and the display of channels, ask them in the comments.
We have collected 10 of the most popular reasons and talked about how to solve them.
On October 14, in the last regions of Russia, analog terrestrial television was turned off: the country finally * switched to the terrestrial “figure”. Now almost any Russian can watch 20 TV channels and listen to 3 radio channels completely free of charge. But not everyone manages to catch the CETV signal the first time.
Before we move on to the analysis of the reasons, I would like to remind you that if you pay for television, you have it either cable (interactive, Smart TV) or satellite. In DTT, the signal is transmitted over the air (through the "air") from radio broadcasting stations to your home antennas. Digital terrestrial television does not have a subscription fee.
CETV is ideal for homes, kitchens, garages, cottages, villages: anywhere where hundreds of channels and interactive services are not needed.
What do you need to watch CETV?
1. TV or set-top box with DVB-T2 support.
2. UHF antenna.
A good set-top box can be bought for 1,000 rubles, an antenna - for 500 rubles.
And now let's move on to the reasons why you may not show CETV.
Old TV
Your TV does not support the DVB-T2 standard? In the "kinescope" models it is definitely not. In LCD TVs released before 2012-2013 - too. Newer ones should have DVB-T2 support. If in doubt, look at the technical documentation or search the Internet for information by entering the model of your TV receiver into the search.
Solution:
DVB is, but not the same
In 2010, Russia began to build a CETV network based on the DVB-T standard, but two years later they switched to a more modern and advanced DVB-T2. The DVB-T standard is still used in some countries around the world, but it is not compatible with DVB-T2.
Solution: Buy a DVB-T2 set-top box or a new TV.
Wrong connection
If you are using a set-top box, the antenna must be connected to it, and the set-top box to the TV. If available, use an HDMI cable connection. It may not be included with the TV set-top box. But there will certainly be an AV connector, popularly called "tulips". Yellow for video, white for left channel (or mono), red for right. Do not confuse.
On older TVs, you will only find a SCART connector. You will need an adapter.
Solution: check all connections.
Wrong TV mode
If you are connecting a set-top box, you must select the appropriate mode in the TV receiver. In this case, you need to scan TV channels through the set-top box menu, and not the TV menu.
If you have a TV with DVB-T2, please select the correct signal source before searching for TV channels.
Solution: read the instructions.
Faulty hardware
Anything can break: a set-top box, an antenna, a TV. If you suspect marriage, use your consumer rights. Sometimes there are also funny reasons in the form of dead batteries.
Solution: replace defective hardware.
Antenna pointed in the wrong direction
If the nearest tower from where the DTT is broadcasting is close, the antenna does not have to be pointed strictly at the signal source. If the tower is far away, more fine tuning is required. How to find out the location of the towers? Open the official map: https://map.rtrs.rf/. It is advisable to check several towers, including those located in neighboring regions.
On the same site, the frequencies at which the first and second multiplexes are broadcast are indicated (multiplexes are blocks of 10 TV channels each). Thus, instead of auto-search for the entire UHF range, you can immediately specify the desired frequencies in the settings.
If the signal is weak, the antenna must be taken out into the street, raised higher so that walls and ceilings do not interfere. By the way, in cities you can catch a TV signal reflected from buildings.
Solution: to find the optimal signal strength, you will need an assistant who will monitor the quality depending on the location and direction of the antenna.
Weak signal strength
If you raised the antenna to the maximum height, checked all the neighboring towers, but there is no signal, or it is weak, you can try to amplify it. To do this, use an antenna with a higher gain (active or passive).
Solution: buy a more powerful antenna.
Technical work on the tower
The schedule of preventive work is published on the website of the local branch of the RTRS. There may be unplanned outages.
Solution: wait or call the regional RTRS.
Weather
During analog broadcasting in heavy rain and snow, the signal quality deteriorated significantly (the so-called “snow” appeared, the color disappeared, etc.). CETV is more stable in this regard, but in bad weather you may encounter picture freezes and short-term blackouts.
Solution: wait for the weather to improve.
You are outside the coverage area of the RTRS network
More than 5 thousand transmitting stations have been built in the country, but they do not cover the entire territory. By
Digital television is set up and working and suddenly the image disappears or instead of it there are squares and snow on the screen. Why does the digital set-top box not show anything and only writes that there is no signal. The reasons may be different, and each failure is corrected in its own way.
After the set-top box has been set up and has been working for a while, the image may disappear. There are several reasons for a TV to fail.
First you need to determine why it is written that there is no signal:
- planned preventive work;
- unscheduled repair of provider networks;
- no translation;
- failure in the equipment of the set-top box;
- natural factors.
Some causes will disappear on their own. Others require reconfiguration and repair of equipment.
Repair work on the line
Even in well-established television broadcasting systems, technical work is periodically carried out. They are carried out according to the approved schedule and consumers of services are warned in advance. If the screen is blue and the prefix says that there is no signal, you can contact the provider and clarify the reason why the signal is lost.
Given that the figure is just beginning to enter the country and all equipment requires debugging and fine-tuning, unforeseen repairs may occur. The provider will also inform you about them by phone if you call him.
No broadcast
If the signal drops out at certain times of the day, the reason may be that there are no transmissions. All digital channels work around the clock. The provider may have its own broadcast schedule and breaks.
Working hours are usually specified in the contract. During the breaks in the work of analog television, a special screensaver is displayed on the screen. Digital broadcasting is based on other technologies and simply turns off the signal. It is worth turning on the TV at another, familiar time. All programs will be available.
Software failure of the receiver or tuner
Malfunctions in home equipment can be expressed in different ways:
- the inscription "no signal";
- instead of the image, colored rectangles or "snow";
- poor picture and late sound.
The inscription about the absence of a signal can be on a blue clean background and with poor image quality. In the first case, the signal does not completely enter the receiver and attention should be paid to the antenna if everything is in order with the provider.
If there is a fragmented image in the form of squares or flashing snow, the signal arrives at the tuner, but it is not strong enough or cannot be converted by the TV set-top box.
The first step is to reprogram the digital receiver. To do this, it is disconnected from the network with a button on the case. In order not to confuse what to press, you can simply pull the plug out of the socket. After 5 - 7 minutes, the prefix turns on.
If it doesn't work, go back and see if there are any updates.
If nothing has changed, the reason why there is no signal should be looked for elsewhere:
- the antenna does not catch waves or they are very weak;
- Defective firmware in the console;
- equipment incompatibility;
- there was a malfunction electronic system receiver.
The antenna picks up direct and reflected signals well. A feature of decimeter waves is high cross-country ability and at the same time sensitivity to obstacles. It is enough to be in the path of the waves to be a high hill, a brick fence or walls of houses, as the beam goes out or is reflected in another direction.
If there are such obstacles nearby, measures should be taken to catch the reflected waves from the repeater, determining the maximum power in a practical way.
- Look for possible obstacles.
- Raise the outdoor antenna higher, put the indoor antenna on the windowsill.
- Turn the tuner in different directions in search of stable reception.
- Connect an amplifier to the antenna.
In an urban microdistrict, residents of the lower floors take out receiving equipment to the roof, determine the direction of the best signal. In areas with poor coverage, you should install an amplifier or immediately purchase a tuner with a built-in node.
When setting up a room antenna, it is placed on the windowsill or taken out of the window. The circle should be rotated, it is he who receives the hd signal, the horns catch waves in the millimeter range. After making sure that the cause is in the signal, you should find the optimal place and position for the tuner.
What to do if there is some image on the screen, but the prefix does not work. The cables and antenna contacts should be checked. In the event of a break, the receiver does not receive the HD broadcast from the tuner.
You can determine the strength of the waves for digital television through a manual search. A weak flow of waves is not reflected by auto-search, it does not accept it. When the message on the monitor "no services", you should switch to manual settings. A graph with signal intensity as a percentage will appear on the screen.
A digital receiver will produce a high-quality picture and sound at 60 - 80% of the transmitted digital stream. At lower values there will be noise in the form of snow, the picture is fragmented.
Consistently poor picture is obtained when the transmission format equipment is incompatible. DVB T receiver cannot support DVB T2 format.
In this case, a distorted or fragmented picture will appear, or there will be no signal at all. The antenna will transmit it, but the set-top box will not be able to fully process it.
For a television receiver, the cause of the lack of reception may be poor-quality firmware of the set-top box. If TV shows are not produced on the screen in this browser and the sound slows down or completely disappeared, you must again update the firmware.
To do this, go to the website of the equipment manufacturer and download desired program. With insufficient experience in handling computer programs you need to contact a specialist.
In areas with unstable current in the network, power surges may cause an electronic malfunction. Consumer guidance advice will not be enough.
It is impossible to fix the failure in the program on your own. It is necessary to contact the workshop with special equipment. This is typical for outdoor TV set-top boxes.
LG TV with a built-in set-top box has protection against power surges - a built-in stabilizer. If television receivers do not have such a node, an outdoor unit should be installed.
Influence of weather conditions
The consumer manual describes in detail how to set up television receivers after connection.
If all channels worked fine, and then suddenly disappeared, you should pay attention to the weather, what exactly happened:
- rain;
- thunderstorm;
- wind;
- severe frost or heat.
Weather conditions affect the quality of the picture, the sound slows down and disappears, thick “snow” appears and the image is not visible. A situation where the signal partially passes, but it is impossible to watch the transmission.
Lightning entering a cable can cause a strong power surge or create a static field. This affects the operation of the equipment and the transmitted image quality.
High humidity after rain affects the conductivity, changes the characteristics of the signal. You should turn on the TV after a while after natural phenomena. If the situation does not change and the prefix does not work, you should look for other reasons. In any case, it is necessary to require the provider to set up the equipment.
