What If There Is No Signal On The TV? Why Does Not It Show From The Antenna And Digital Channels Stopped Working? How Do I Troubleshoot?

2024 Author: Beatrice Philips | [email protected]. Last modified: 2024-01-18 12:09

What to do if there is no signal on the TV, why does not it show from the antenna, digital channels stopped working - with these questions, the owners of modern TV equipment often contact service centers. In fact, most problems are fairly easy to fix on your own. How to do this and not harm the TV is worth talking in more detail.

How can I determine the cause of the problem?

The lack of a TV signal is a fairly common problem that both owners of modern Smart TVs and owners of analog models face. Here you need clarify the source of the data . For example, it shows a device from an antenna or a satellite dish, or maybe it is connected to cable networks. In addition, it is worth clarifying whether the receiver works, if it is installed, whether the cable is fixed.

Among the common reasons why there is no signal on the TV, several can be noted

Incorrect installation of the "plate " … In this case, the receiver may broadcast a very weak signal or not transmit it at all. There can be separate channels, appear and disappear. In addition, the quality of the signal is influenced by the operating conditions: the icy "saucer" always works worse.

Damaged cable … This happens especially often when the signal source is located outdoors. In this case, it can pass, but very weakly. More often than not, the TV screen will simply display “No Signal”.

The built-in receiver or external set-top box is broken . The specialists of the service center can more accurately diagnose the breakdown. Independent attempts to disassemble a complex electronic device may result in its complete failure.

Doesn't show satellite or cable TV . Usually the problem appears only at certain hours, without any preliminary "symptoms" of signal deterioration. It is worth checking the data on the website of the operator - the service provider. During maintenance, TV signal reception will be unavailable. The data on the performance of work can also be in the receiver menu, in the decoder settings section.

The prefix is frozen, the signal has disappeared . This is a common problem with cable TV repeaters. A banal reboot with disconnection of the device from the network for 30-60 seconds will help to solve the problem.

The signal from the satellite dish was lost due to external reasons . This is usually due to the appearance of interference or a change in the direction of the antenna. For example, it can be displaced by a strong wind, hail, a bird sitting on top. And also a new building in neighboring areas may be in the way of stable reception. Finding a better position for the antenna will help solve the problem.

Smart TV version is outdated . If the old OS is no longer supported, the signal on the TV will disappear. You need to download the update and install it from a USB drive or connect the device to Wi-Fi. Set-top boxes are usually updated automatically.

These are the main problems, the causes of which can be identified by the user on his own by a cursory examination of the problem. If you need more in-depth diagnostics, you should first take a closer look at exactly how the screen looks after loading, what TV functions are available.

Typical problems

It is always necessary to consider the problems arising with the supply of a stable television signal in combination . If all external causes are excluded or it is not possible to reliably establish them, it is worth paying close attention to the accompanying factors . For example, the presence of any image, inscriptions on the screen. All this data will help to get a better understanding of the source of the malfunction.

The screen is missing

The complete or partial disappearance of the image usually says about technical problems in the TV itself … A more accurate "diagnosis" will depend on what can be established in the course of self-diagnosis.

Blue background

Most often, when the user speaks about the absence of a picture, they mean a blue background that appears instead of the broadcast image. If we are talking about CRT TV, we can talk about memory interruptions or breakdown of the video amplifier responsible for this tone . On a plasma display, the source of this problem is breakdown of the signal processing unit . There are several of them, it is possible to establish exactly which module is faulty only in the workshop.

If a blue screen appears on an LED TV or LCD screen, the problem is in the matrix . It needs a complete replacement, comparable to the cost of the device itself. A blue screen, on which there is an image - channel numbers, menu items, appears when there is no signal. The reason may lie in the antenna or cable, as well as in the incorrectly selected operating mode of the device.

The image disappeared after turning on

If the splash screen with the name of the brand or operating system on a modern LCD TV loads normally, and then the image disappears, it is worth looking for a breakdown. in the field of cable connection, tuner . Contact with the signal source may have deteriorated due to a wire that fell out of the socket. There will be no image, perhaps the reason lies in turning off the broadcast of the picture from the remote control … At the same time, the sound is broadcast normally, the channels are switched. All that remains is to press the button that cancels the operation without a picture.

Black or partially black screen

The complete lack of reaction to switching on, the black color of the screen usually indicates that the breakdown is quite serious. There are several probable reasons worth noting.

• Defective backlight . In this case, the TV retains all functions except for adjusting the brightness of the screen. By shining a flashlight on it, you can see the image. Replacement of the LED backlight is carried out at the service center. If you perform work on your own, you can damage the matrix or other parts.
• The TV does not turn on at all, there is a noticeable smell of burning around . Most likely, the reason is a surge in the mains voltage. It is necessary to de-energize the device, contact a repair specialist.
• Black screen with a horizontal stripe of light or bright color . The reason is the frame scan. The problem is found mainly in CRT TVs, it is solved by replacing the unit. The vertical bar indicates a breakdown of the transformer in the line scan unit.
• The TV turns on, the screen turns off immediately . Most likely, the matter is in poor power supply from the mains. It is necessary to check the wire and the power supply, the outlet, the presence of voltage in the entire apartment.
• There is no sound or image, the display is on . The video processor is probably broken.

These are just some of the reasons why the picture on the screen may disappear. If the breakdown is serious, it is better not to leave the device plugged in, you should try to call the master as soon as possible.

No digital channels

The problem with the transition to an all-digital TV signal has led to a lot of questions from consumers. If your TV has a cable connection, the instability of the incoming data can be associated with many factors . For example, with the influence of external interference: ignition systems on cars, birds, poor quality of the general house signal amplifier. Do not assume that your TV or set-top box is broken. Sometimes, due to routine maintenance work and even bad weather, it can be quite difficult to catch a signal.

To minimize losses in the quality of data transmission over DVB-T2, you need to correctly position the cable through which it is connected . The higher the wire is, the more interference will affect the signal. In addition, its distance from the set-top box itself is also important - an external receiver or built-in TV unit.

Lost digital channels may be due to weather conditions : Reception will be better in winter than in summer in hot weather. The presence of dense foliage on trees during warm periods of the year can screen the signal from the antenna installed outdoors. If the problem persists for a long time, it makes sense to purchase an amplifier. It is placed next to the antenna, as close as possible. Channel reception will become more confident.

Connection through an external receiver - set-top box, may be disrupted due to the interruption of the contact of the plug with the jack of the TV or the receiver itself . This happens especially often if the devices have been moved or shifted. The slightest effort or jerk will cause the SCART or "tulip" to stop broadcasting the picture. In addition, a break may occur in the cable: it is worth buying a new one and testing it in operation.

Important! If not all, but only some of the channels disappear, the problem may be in receiving signals from several sources. Manual setting of the STB will help to solve the problem.

What does the inscription mean?

Usually, the TV reports the absence of a signal on the monitor when it is turned on or during the operation of the equipment . Modern Smart TVs issue such a system letter with prompts. For example, the message may contain information about where the cause of the loss is located: there is no contact with the network cable. Such informational tips can be very useful for an inexperienced user who just wants to watch a favorite TV series or a long-awaited blockbuster on TV.

The “No Signal” sign does not need to be permanently displayed. Sometimes she interrupts the broadcast, then disappears. Such short-term interference is usually associated with the passage of vehicles, the effect of wind gusts on the antenna . The inscription "No signal" also appears before the TV is turned off due to a drop in the mains voltage. In any case, the reasons for the disappearance are not in the TV itself, but you need to look for them in the sources of external connection.

What does the signal level depend on?

The quality of a TV signal, even in digital format, is a rather unstable concept . It can be influenced by weather conditions: cloudiness, wind strength, and other external disturbances. If the TV showed poorly in the morning, and by the evening it stopped picking up the signal at all, you should make sure that such sources of problems did not appear suddenly. For example, in case of strong cloudiness, during snowfall, the TV may show a blank screen until the noise disappears.

The appearance of a mechanical barrier: a new building, structure, can become a serious problem for broadcasting a television signal. In this case, find the optimal receiving point by moving the antenna. The signal level in TVs working with DVB-T2 varies from 60 to 84 dBμV - these are standard values. The more noisy the image, the more difficult it will be to adjust. This indicator will be different for each frequency. The use of coaxial cables helps to reduce the influence of external noise.

How to fix?

Sometimes very little is needed to eliminate the malfunctions that have arisen during the transmission of the signal. For example, if digital channels have partially disappeared on a dish, indoor or outdoor antenna, they can be turned back on through manual tuning of the tuner. This is done as follows:

• specifying the numbers of multiplex channels for a specific region;
• manually set the settings for each of them.

Impulse noise , causing a temporary interruption of the signal, are associated with the start of the ignition systems of motor vehicles. Their influence can also be reduced by replacing the conventional cable with a double-shielded coaxial cable or by moving the antenna higher.

It is almost impossible to fix a TV, the breakdown of which is associated with technical malfunctions of the device itself, at home . Of course, a radio amateur with a full-fledged workshop will cope with this task. But for an unprepared owner, it is better not to open the device case on their own, since even the residual voltage on its parts is very dangerous to health.

A missing AV signal may be due to a forced mode change . Using the Source or AV / TV button on the remote control, you need to check which parameters are set. If another mode is selected, you need to return to the standard values. On a new TV, the “No Signal” mark indicates that you need to connect the antenna and tune the channels.