LED screen appears black and dull. What should I do?

Jun 8, 2022, 7:42:27 AM

Looking at the development of large screen display industry in recent years, it is not difficult to see that no seams and high image quality are the ultimate pursuit of large screen display.

In the current mainstream display technology, LCD splicing has obvious seams, so it is difficult to launch an impact on the areas with high picture integrity, such as the broadcasting guide room and the Meteorological Bureau. This field is also the core battlefield for small spacing led to launch an impact on DLP.

 

LED display screen


Although the technology of LED display screen is very mature, there are always some problems in the process of use. The following will mainly introduce the common faults and solutions of LED display screen.


What is the reason for the black LED screen?


During the application of the control system, we occasionally encounter the phenomenon that the LED screen is completely black. The same phenomenon may be caused by a variety of different reasons. Even the process of screen darkening will vary according to different operations or different environments. For example, it may turn black at the moment of power on, it may turn black during loading, or it may turn black after sending, etc

1. Make sure that all hardware, including the control system, is powered on correctly. (+5v, do not connect reversely or wrongly)

2. Check and repeatedly confirm whether the serial port cable used to connect the controller is loose or falling off. (if the screen turns black during the loading process, it is likely to be caused by this reason, that is, the communication line is broken due to looseness during the communication process, so the screen turns black. Do not think that the screen body does not move, and the line cannot be loosened. Please check it. It is very important to solve the problem quickly.)

3. Check and confirm whether the LED screen and the hub distribution board connected to the main control card are tightly connected and inserted reversely.

 

LED display screen


Why does the LED display screen appear bright lines for a few seconds or the screen image becomes blurred when it is just powered on?


After the screen controller is properly connected with the computer, hub distribution board and screen, it is necessary to provide +5v power supply to the controller to make it work normally (at this time, do not directly connect with 220V voltage). At the moment of power on, a bright line or "flower screen" will appear on the screen for several seconds, which is a normal test phenomenon to remind the user that the screen is about to start working normally. Within 2 seconds, the phenomenon will be eliminated automatically and the screen will enter the normal working state.


The reason why the whole screen of the unit board is not bright or dark


1. Visually check whether the power connection line, 26p cable between the unit boards and the power module indicator are normal.

2. Use a multimeter to measure whether the unit board has normal voltage, and then measure whether the voltage output of the power module is normal. If not, it is judged that the power module is broken.

3. Measure the low voltage of the power module, and adjust the fine adjustment (the fine adjustment at the power module near the indicator light) to make the voltage reach the standard.

 

LED display screen


What are the reasons for the load failure or communication failure?


The reasons for communication failure and loading failure are roughly the same, which may be caused by the following reasons. Please compare the listed items with the operation:

1. Ensure that the control system hardware is properly powered on.

2. Check and confirm that the serial port line used to connect the controller is a straight line, not a cross line.

3. Check and confirm that the serial port connecting line is intact and that both ends are not loose or falling off.

4. Select the correct product model, the correct transmission mode, the correct serial port number and the correct serial transmission rate according to the LED display control software and the selected control card, and correctly set the address and serial transmission rate on the hardware of the control system according to the dial switch diagram provided in the software.

5. Check whether the jumper cap is loose or falling off; If the jumper cap is not loose, make sure that the jumper cap is oriented correctly.

6. If it still fails to load after the above inspection and correction, please use a multimeter to measure whether the serial port of the connected computer or control system hardware is damaged to confirm whether it should be returned to the computer manufacturer or the control system hardware for testing.

Thank you for watching. I hope it can solve your problems. Sostron is a commercial display solution provider that designs, manufactures, installs and operates LED screens worldwide. If you have any questions, you can consult us!

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