‚ÄčLED black screen: how to quickly locate and solve?

  • How to locate the LED black screen problem, and what solutions do we have? Before you have the ability to locate and solve such problems, you must understand some key points. Now, let's get started!

    Warm up-do you remember the structure of the LED control system?

    What can the LED receiving card tell us?

    LED black screen troubleshooting

    What should I do if the LED full screen is powered off?

    What if part of the LED screen is black?

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    Warm up-remember the structure of the LED control system?

    Before we discuss today's topic, let us review the basic structure of the LED control system that we introduced to readers in the previous article: LED display connection.

    The basic structure of the LED control system is divided into three parts: the control computer, the LED display and the LED display controller.

    The control computer will be connected to the LED controller via a USB cable or an Ethernet cable for sending control commands. And will use HDMI and other signal lines to connect to the controller to transmit video signals.

    After that, there will be a network cable connected to the LED display. In this way, we get the basic structure of the LED control system.

    Sometimes, the LED display processor is involved to process the input source, so that the screen can display the entire picture, or to achieve some effects such as rotation and zooming. Now, we can get the picture as shown below:

    LED display connection

    So, why do we have to quote this concept again? That's because they are all possible factors that cause the screen to power out! Therefore, for further discussion, we retrieve it again for preparation. Now, let's say it bluntly.

    What can the LED receiving card tell us?

    The receiving card will be installed in the LED cabinet. Usually, a cabinet will be equipped with a receiving card. By paying attention to the status of the LED receiving card, we can know the running statue of the screen. Let us take the Novastar control card as an example:

    Novastar control card

    Please pay attention to the green indicator in the picture. This is a signal resource for you to diagnose whether the receiving card is working properly or where the problem is. There are several situations that you need to understand:

    (1) The indicator light flashes once per second: In this case, the receiving card is working normally.

    (2) The indicator light flashes four times in half a second, and then flashes four times after an interval of half a second, indicating that the receiving card is working normally but in the backup mode.

    (3) The indicator light flashes slowly, only once for five seconds. In this case, the network cable may have some problems.

    (4) The indicator light flashes quickly, flashing three times within half a second, which means that there is no signal input. Therefore, maybe we need to replace the signal cable or reconnect it.

    After understanding the four conditions of the LED receiver, we can now move on to the next chapter.

    LED black screen troubleshooting

    Types of LED black screen

    There are two types of power outages for LED displays, including full-screen power outages and partial-screen power outages.

    Part of the power failure of the screen may occur in a specific cabinet, a specific LED display module, and a specific output area of the sending card.

    LED display module

    Why does the dose LED screen turn black?

    As we mentioned before, any part of the LED control system can be the cause of the power failure of the LED screen. Here, we list the reasons and corresponding solutions.

    (1) Screen power

    One. The screen is powered off. Just power on the LED display, then the problem can be solved.

    B. Insufficient power supply. Please replace the power supply to replace the power supply.

    (2) Receiving card

    One. rcfgx file error. Send the original rcfgx file or recreate it and send it.

    B. Firmware error. Please upgrade the correct firmware.

    (3) Video source

    A. Black source. Just check and change the video source.

    B. The cable is disconnected, loose or damaged. Please reconnect or replace the cable.

    C. The video source is not compatible with the LED display. If there is a problem with our sending card firmware program file, please upgrade the correct firmware.

    Sometimes it comes from the wrong video source, so please replace with the correct video source.

    (4) Sending card

    One. The sending card is not powered on. Please turn on the power of the sending card.

    B. Input error. Please select the corresponding input source, such as HDMI or DVI.

    C. There is an input source interface failure. Change another interface or change the sending card.

    (5) Brightness value

    A. 0% brightness. Please increase the brightness, the value is usually 50%.

    B. The screen controls have been powered off. You can adjust the on-screen controls to normal.

    Ethernet cable

    The Ethernet cable may be loose or damaged, then reconnect or replace the Ethernet cable.

    Now that we know the main points, let's talk about the current system approach.

    What should I do if the LED full screen is powered off?

    We can make a preliminary judgment from the red indicator light on the card.

    LED full screen is powered off

    One. If the red indicator light is off, it means there is no power. Then, please check or replace the power supply.

    B. If the red indicator light is on, there may be problems with other points. Check for other possible causes.

    If the situation is B, then check the green indicator as we discussed earlier.

    One. If the green indicator light flashes slowly, it will only be once for five seconds. Please check the sending card and Ethernet cable.

    B. If the green indicator light flashes three times within half a second, and then flashes three times again after 0.5 second interval, please check the video source input because there is no signal input.

    C. If the green indicator light flashes once per second, it means that the receiving card is working normally, then please check the firmware program file of the receiving card or rcfg file to see if there is a problem with these two files. In addition, you can check whether the brightness value is set to 0%.

    What if a part of the LED screen turns black?

    There are three parts of a black LED screen, including power outages of specific modules, power outages of specific cabinets, and power outages of specific output port areas.

    (1) LED module level:

    One. The LED display module power is off. Replace the power supply unit or power cord.

    B. Hub board failure. Change to another connector or change to a new hub board.

    C. The flat cable is loose or faulty. Please reconnect or replace the flat cable.

    (2) LED cabinet level:

    A. The power supply unit is faulty. Please replace the power supply unit.

    B. The Ethernet cable is loose or malfunctioning. Just replace it with a new Ethernet cable or reconnect it.

    C. There is a problem with the receiving card, including wrong rcfg file, firmware and receiving card failure.

    Just perform the corresponding repair method, for example, read the rcfg file from the ordinary receiving card and send it to the receiving card.

    For the wrong firmware, please upgrade the correct firmware. The wrong receiving card can be handled by the new LED receiving card.

    D. Hub board failure. Please replace the hub board with a new one.

    (3) The output level of the LED sending card:

    A. The Ethernet cable is loose or malfunctioning. Just reconnect the Ethernet cable or replace it.

    B. The output port of the LED sending card is faulty. Please change the sending card.

    C. Indicator screen power failure. Replace the power supply or reconnect the power supply.

    The above are the potential causes of LED black gravel and the methods to deal with them. If you encounter any of these situations, just follow the suggestions to locate the problem and solve the problem quickly!

    Now, let us summarize here.

    First, we learned about the different conditions of the green indicator light of the receiving card. We must know four situations.

    (1) If the indicator light flashes 1 time per second, it means that the card is working normally.

    (2) If the indicator light flashes 4 times quickly at 0.5 second intervals, it is in the backup mode.

    (3) If it flashes once every 5 seconds, it means that the network cable has been disconnected.

    (4) If the indicator light flashes 3 times at 0.5 second, it means that there is no signal input.

    Then, we talked about today's topic-LED black screen. It can be divided into two situations, including full LED screen black screen and partial screen power failure.

    For a black LED display, please check the red indicator light of the receiving card first to make sure it is powered on. If it is, please check the other points we mentioned above according to the conditions of the green indicator light (such as the Ethernet cable and the receiving card file).

    In addition, for the black part of the LED screen, there are three levels, including the LED module level, the LED cabinet level and the output port level. Please solve the problem according to the content we listed above.

    in conclusion

    In this article, we discussed a common problem that confuses users and technicians of LED displays-LED black screen. We discussed the method of proving the conditions of receiving the card, because the information we obtained from it can tell us many clues. Then, we introduced you to two screen blackout situations, including full LED screen blackout and partial screen blackout and solutions!