Many people are faced with the problem when, after purchase, their TV does not pick up channels. Do not immediately get upset and rush to return the goods back to the store. Often, most problems can be solved by yourself.
Digital broadcasting is a technology in which the transmission of picture and sound occurs using compressed coded signals. This method transmission has many advantages over analog:
- excellent quality of transmitted picture and sound;
- immunity from interference;
- ability to transfer a large number of channels;
- simple and fast setup;
- Internet access.
Reasons for the problem
In fact, the reasons why the TV does not find channels is huge. Let's look at the most common of them:
- Incorrect UHF antenna type. It is possible that the antenna you have installed is not suitable for digital channels.
- Wrong direction of TV antenna. This problem may occur due to the location of the antenna in the opposite direction from the main broadcast station.
- The receiver is disabled or defective. Such an option is not excluded. It is worth carefully checking the correct connection of the receiver, as well as its performance.
- Highly weak signal reception. If, after checking all the previous reasons, you have not found any problems, it is worth checking your receiving device. It is possible that its signal is not enough to find channels.
- Old firmware version. Outdated TV firmware can also cause this problem. You can update the firmware yourself by downloading and installing desired file from the official website of your TV model. If you have equipment from Samsung, respectively, you need to go to the Samsung.com website. However, we advise you to transfer this matter to professional hands by contacting a service center.
- Read also.
How to fix the problem?
If you still don't know why your TV can't find digital channels Let's try to explain in detail the solution to this issue.
Connection methods
It is quite possible that this problem occurs due to the wrong way to connect to digital broadcasting. Each method has advantages and disadvantages. However, before you start searching for channels, you must connect the equipment correctly. Consider these options:
- Using a decimeter antenna. AT this case you need to connect a TV antenna and an amplifier to your signal receiver, then connect it to your TV. Next, select auto search and wait for the result.
- Via cable. A large number of providers provide digital television services. Almost in all modern TVs there are built-in signal cards. In this case, to receive a signal, just plug the cable into the socket and turn on automatic search channels. Of course, this service is paid.
Search settings
It is possible that the problem lies in incorrect setting search. The setup scheme in all TVs is almost the same, so you should not have any difficulties. In this case, we recommend that you do the following manipulations in order to make sure that the settings are correct:
- Enter the "Settings" or "Broadcast" section.
- Locate the "Search for channels" option.
- Click on "Auto Search" or "Auto Setup".
- Select your connection type (described above).
- Select the search mode "Full" and the type of channels you want to search (analogue or digital).
- Click Search or Scan.
- Sort the found ones.
Thereafter correct setting search will be completed. If you failed to catch more than one channel, we advise you to read factory manual your TV or receiver. Perhaps you will find a solution to this problem there. In extreme cases, you need to contact the TV tuning specialists who will find and fix the problem.
The TV from the antenna does not show well - there are two reasons. Device inconsistency, bad hardware. The last one concerns the antenna, television receivers one way or another they get the job done. However, the problem lies in the amplifier. Should though be set to desired frequency. Below we consider typical situations, methods for solving the simplest methods. The easy way is to buy satellite dish, put. Alternatively, stop watching TV, the Internet is much more fun!
Cable problems
It sounds ridiculous, but the first thing to do is to check the cable. There are several requirements that you must follow:
- First, wave resistance television cable is 75 ohms. Deviations in the value provoke reflection of part of the power in the path, which will inevitably lead to losses. Coordination methods have been invented, using which it is allowed to use a cable of a different wave impedance. Time to fence the garden. Devices designed to work television broadcasting, wave impedance 75 Ohm. We take into account the truism when choosing a cable.
- The second tip concerns the owners of indoor antennas. A typical picture: a wave channel, a half-wave vibrator with antennae hang, a coil of cable lies nearby. First of all, we look at whether the antenna is active or passive. Need to turn on the power? If it turned out to be passive, cut off the extra cable, decorate the pantry with a bay. The feeder segment introduces irreparable signal losses. In an antenna receiver, the sensitivity strongly depends on the attenuation up to the first amplifying stage. In our case, this is inside the TV, the cable to the jack introduces incredible losses. Another thing is the active antenna. The first amplifying stage is located here, the cable length becomes non-critical.
- If a passive antenna on the roof, not bad to get hold of, using the Internet, the characteristics of the cable. It is logical to see if the linear loss exceeds 0.2 dB. Attenuation determines the length of the feeder, electrical characteristics products. Three meters of good cable contribute attenuation, equal to a meter cheap. It is recommended to install an amplifying antenna, replace the cable. Fortunately, television is inexpensive. Forget the high cost of high-frequency WiFi!
Why you need an active antenna
They mentioned that if the antenna is active, the length of the cable is acceptable, the losses should not be considered a critical element. If a good wire cannot be obtained, the length cannot be reduced, the roof is far away, it is supposed to be bought active antenna. Please note: to install the equipment, you will need permission from the HOA, the owner of the house. Insanity is observed: harnessed to compose special plan accommodation engineering communications, having paid a fee to a specialized company, pay a professional master who performs the installation. You have to do it according to the rules.
The amplifier for the antenna will allow you to bypass the restrictions imposed on the quality and length of the cable. The power cord will often need to be pulled up to the roof. The distance to the TV station is small, the point is simply blocked by houses - we recommend trying to catch the signal with a room variety. TV will show without common antenna. It is allowed to place the "cheburashka", decorating the balcony, even above the false ceiling. The paths of the reflected beam are inscrutable. However, conditions change according to the weather, reception will deteriorate (or improve). It is recommended to give preference to omnidirectional antennas with a lower directivity, supplied with an additional external amplifier.
Detect Antennas significant disadvantage, which has nothing to do with the reception quality of an individual signal. The sources of problems are explained by the multipath effect. An omnidirectional antenna receives from all directions (azimuths). Several rays will hit, the image will begin to double. A similar effect causes overamplification. Take away food electric shock, see the result. The same way reddish snow is removed. The reason is the same - overstretching.
Advice! Adjust the equipment in an attempt to obtain desired characteristics. Reduce the gain. Buy a TV attenuator. These will reduce the gain by twenty dB.
An indisputable drawback of omnidirectional antennas has been noticed: interference sources will act from all sides, sharply lowering the signal-to-noise ratio. This is not critical for digital multiplexes, broadcasting contains error correction codes. Reception analog television an antenna with an amplifier is not possible if the noise increases above the level of the useful component.
Antenna selection and installation
The antenna itself may not match the received signal, or it may not be installed correctly. Many people know that it is useful to orient the device in space, but not everyone knows how to do it. Television in Russia on the UHF is built on horizontal polarization, so the distortion of the half-wave vibrator or wave channel with a guarantee leads to a deterioration in reception. It also shifts frequency range, due to which the quality of the picture further decreases.
It will be necessary, using the level, to set the antenna in the correct position. In addition, when receiving from distant TV towers, a simple rule applies. The higher the antenna is placed, the more likely it is to catch the broadcast. This rule applies to the UHF, which is why the MW and HF bands still remain attractive. Waves at these frequencies bend around the surface of the earth, so you can catch it without even taking the antenna to the roof.
External barriers also contribute, if there is a forest around, then the reception will be worse. Waves attenuate as they pass through obstacles. In this case, it is recommended to get an antenna with an amplifier. Plays a role and type. Full-wave vibrators receive a signal much better, and it is difficult to get it in a store. Will help homemade antenna. Made from a core of copper or aluminum cable and installed according to the rules will provide best reception than store.
It has already been told more than once how to make a narrow-band antenna that is tuned to the channel frequency. In this case, it is also possible to achieve excellent results. simple ways. After all, hobbyists even construct quarter-wave vibrators for digital receivers. It's just a short piece of wire with a quarter-wavelength screen stripped off at one end. For the first multiplex in Moscow, this is 13.5 cm. A connector is soldered to the other end, which is inserted into the receiver. The quarter-wave vibrator is placed horizontally. Can be bent at the base for easy placement if needed. Even such a simple and inconsistent design yields results in television broadcast reception.
Wave channel antenna matching
Beginners are concerned about the question of how to properly match wave channel type antennas. The designs are very simple, give excellent gain. The design is ideal for UHF, where they lie digital multiplexes. First, let's consider signal balancing. An operation will be required if the descent cable is longer than 10 meters. The device is a piece of wire parallel to the feeder, spaced 3-5 cm apart.
The method is suitable for a wave channel made according to standard rules. The screen of the drop cable simply sits on one side of the active vibrator, but on the other side the balancing cable segment clings. The length depends on the channel, for example, for the first Moscow multiplex it is 17.6 cm. The piece is parallel to the drop cable for its full length. How to connect the device:
- The core of the balancing device is placed on one side of the active vibrator parallel to the core of the drop cable. The braid of the segment closes here.
- At a distance of the length of the balancing device from the active vibrator, the insulation of the drop cable is stripped. The screens of the parallel wires are closed, the second end of the segment core is also connected here.
The situation is much more complicated with antennas whose impedance is below 75 ohms. Then special matching devices are used. The active vibrator can be made T-shaped. Top part loops are built up with an additional wire in both directions. The total length is calculated by the formula:
L = (λ/2)*(1 – 0.225/ln(λ/2d)), where
λ is the wavelength, m; d is the wire diameter expressed in meters. The height of the loop is equal to one hundredth of λ or slightly less. The loop width is selected experimentally, the impedance is sought to be brought closer to 75 ohms. Dependency graph "hunchbacked". The maximum is observed at a loop width equal to λ/4.
By designing your own antenna, the method selects the overwhelming number of radio amateurs, will make it possible to manufacture a device with the desired wave impedance. Having a drawing in hand, duplicate the design a given number of times. Get ready to work hard if the TV does not show well. Find out the frequency of broadcasting, make a special antenna.
Signal interference will be minimal in this case. Design procedure wave channels described. Explore the portal! Let's gather our strength, consider the design of log-periodic antennas, just wondering how to do it. Product feature - I catch wide range broadcasting. The coverage of a log-periodic antenna is amazing.
The systematic shutdown of analogue television broadcasting in favor of the "figure" is in full swing. Digital TV is not only high quality broadcast image and sound, but also a stable broadcast. However, sometimes problems with television still arise. As a result, the device does not catch digital channels.
When you first start the receiver, the user sets up TV channels. Mostly this process is carried out automatically. However, what to do if bad signal Can't tune the channels included in the two free multiplexes on the TV?
There may actually be several reasons. It's about them now will be discussed. Let's take a closer look at the main difficulties faced by users in order to answer the question why it doesn't show today digital television. We give real arguments and effective ways solutions to emerging problems.
Reasons for not showing digital channels
Conventionally, all the reasons can be divided into 4 categories:
- hardware or software failure in the operation of the equipment;
- conducting repair work;
- natural factor;
- stop broadcasting.
Of course, you first need to determine why digital television does not work. Diagnosis is reduced to the study of symptoms, for example, if the image becomes square or the sound is delayed, then this may be due to bad weather or a thunderstorm.
It is almost impossible to avoid these problems, since for the most part they are of a force majeure nature. The only exception is hardware failure. Preventing software failures is quite simple - update in a timely manner operating system prefixes. It is even easier with hardware damage - follow the rules for operating the equipment.
Now let's take a closer look at what the quality of broadcasting depends on, and also determine why there is no signal on digital television. Let's focus on the most common reasons that have already been voiced earlier.
Equipment is out of order
If not working cable TV, then you first need to figure out what exactly caused the failure:
- receiver failure;
- antenna damage;
- cable failure.
First, let's deal with incorrect work digital set-top box. It makes no sense to focus on this point in too much detail, since the symptoms of a receiver failure are obvious. When the receiver is turned on, the indicators will not light up, indicating that the equipment has started. Sometimes the LED is on, but extremely dim.
Many tuners are equipped with an independent 5 volt power supply. Predominantly set-top boxes are equipped standard adapter, so it is extremely easy to check its performance, you can connect a similar component from the router.
In some situations, testing the voltage level with a multimeter does not give results, because in the absence of loads, the measurement will show the 5 Volts established by the regulations.
Bad sound from the DVB-T2 tuner is another symptom. Sometimes the device simply reboots or randomly turns off, does not respond to commands from remote control management.
Another common type of hardware problem is cable and connection failure. As a result, absolutely all channels do not show, because the signal is lost. Carefully check absolutely all connections and cable integrity.
Particular attention should be paid to the white wire (RG-6), which is intended for internal wiring. The service life of this cable is extremely short, especially if you used it in the process of external laying. Water gets into it, thereby destroying the braid.
The third cause of equipment problems is antenna failure. indoor antennas fail extremely rarely, unlike external ones. Predominantly, precipitation or a thunderstorm become a catalyst for a malfunction. You can try to reconfigure the receiver several times, but the channels will not be found. In this case, follow the proven algorithm of actions:
- Check cable and plugs.
- Evaluate the voltage supply from the set-top box or power adapter.
- Connect a new antenna.
Remember, if the antenna for some reason does not pick up channels, check if it is really directed at the signal transmitter.
All the factors listed above fully explain why the TV does not catch channels. Modern models TVs are equipped with built-in T2 set-top boxes, which also sometimes fail.
Bad weather
If you have had to deal with satellite TV, then you probably know that during rain or heavy snow, the picture literally crumbles into squares or disappears altogether. With digital DVB television similar problems occur with excessive precipitation.
A weak signal comes from the antenna to the receiver, because of this, the TV does not show well in bad weather. Determining this problem is extremely simple, you just need to test the signal level. If there is no digital television signal or it is very weak, it is necessary to increase it, mainly for this additional devices- amplifiers.
Broadcast termination
If digital TV channels do not work due to prevention, then go to the rtrs.ru website, information about the time and duration of such events is displayed here. In addition, a sign with the corresponding notification will appear on the TV screen.
Sometimes the receiver catches only 10 channels of the first multiplex, but at the same time, just yesterday there was a broadcast of the second package. In this case, check its signal strength. If he zero, then most likely the second multiplex is simply disabled. This is mainly due to broadcasting in test mode. After the equipment collected the information, the TV channels disappeared.
As mentioned earlier, the first multiplex is mandatory, so it works correctly on almost the entire territory of Russia. There are certain difficulties with the second multiplex. Much of this is due to a lack of funding. In addition, analog TV is still active in some regions, so free frequencies simply not enough.
A complete rejection of analogue television broadcasting will contribute to the early emergence of a second multiplex in all regions of Russia.
Repair work
We have already established what causes the digital television signal to disappear, the reasons can be really different. For example, sometimes TV does not work during the day due to regular or force majeure repairs. You can also find out about this by visiting the site rtrs.ru. Often they are held after severe bad weather, which causes damage to the equipment located on the tower.
Seal
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
- termination of the broadcast;
- weather;
- equipment malfunction.
Broadcast termination
When conducting preventive work on the site rtrs.ru in your region you can find information about the time of their holding, 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
Who has dealt with satellite equipment he knows 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.
Quite a lot of people are faced with such a very unpleasant situation when they acquire new tv, but he does not catch digital channels. But digital television these are the technologies of the future, and very soon all TV channels in our country will switch only to this modern format. Do not be afraid that your TV is not suitable for receiving digital television, since most of the problems due to which the TV does not pick up these channels can be eliminated. Let's consider them in more detail.
- Are you using cable or satellite set-top box. Don't worry that without this device you will not be able to watch digital channels. You can, but first you need to find them. To do this, you first need to make sure that antenna cable connected to the TV. We go to the TV menu, and select the item search for channels, which is usually located in the configuration folder. The TV starts searching for digital channels to be added to the channel list in addition to the analogue ones.
- It is possible that the signal from the antenna is too weak. You need to purchase another antenna, more powerful.
- It is possible that your TV does not support the broadcast format adopted in Russia (this happens especially often with TVs that are not intended for the domestic market). In this case, it is necessary to contact specialists who can accurately determine whether it is possible to reflash this model TV so that it can receive Russian digital channels.
- Your TV does not support new format digital television. This is directly related to the fact that the Government of Russia decided to postpone the start of digital terrestrial TV broadcasting in DVB-T format 2 for 2012. Thanks to this decision, in those regions of the country where DVB-T2 was not introduced in parallel with DVB-T, but was replaced by it, TVs of almost all manufacturers stopped receiving digital terrestrial TV. In order to watch TV in DVB-T2 format, you need to purchase an appropriate receiver. However, for example, residents of Moscow were not affected by this problem, since the Moscow authorities found a way to keep broadcasting in the DVB-T format in parallel with DVB-T2.
- The firmware of your TV is outdated, and even though it has the ability to view digital TV, it cannot cope with this function. To fix the situation, you need to reflash the TV. You can do this both on your own by downloading the firmware from the manufacturer’s website, and from specialists who repair TVs. Trying to save money by risking breaking your TV or trusting professionals is up to you.
In fact, there are a lot of reasons why the TV does not catch such channels, and we have given only the most common of them. Therefore, if your TV does not want to catch digital channels, then it is best for you to contact the TV Service Center company. It's really optimal solution, since our technicians will help you in any situation, they will carry out an accurate diagnosis and fix the malfunction of your TV in the shortest possible time. And you do not need to take your TV anywhere - experts will come to your home.
