The LED display screen is usually composed of a main controller, a scanning board, a display control unit and an LED display body. The main controller obtains the brightness data of each pixel of a screen from the computer display card, and then allocates it to several scanning boards, each scanning The board is responsible for controlling several rows (columns) on the LED display screen, and the LED display signal on each row (column) is serially transmitted through the display control units of this row, and each display control unit faces the LED directly Display body. The work of the main controller is to convert the signal that the computer displays with the card into the data and control signal format required by the LED display. The function of the display control unit is similar to that of the image display screen. It is generally composed of a shift register latch with a gray level control function. It’s just that the scale of video LED displays is often larger, so integrated circuits with larger integrated scales should be used. The role of the scan board is the so-called link between the previous and the next. On the one hand, it receives the video signal from the main controller, and on the other hand, it transmits the data belonging to this level to its own display control units, and at the same time, it also transfers the data that does not belong to this level down. A cascaded scan board transmission. The difference between the video signal and LED display data in terms of space, time, sequence, etc., requires a scanning board to coordinate.

Error exclusion

1. No display

Check the power connection, confirm whether the power light and the light on the control card are on, and measure the voltage of the power control card and the unit board to see if they are normal. If the power supply is normal, please check the connection between the control control card and the unit board. Use replacement parts to eliminate errors.

2. Display confusion

In case 1, 2 unit boards display the same content. –Please use the software to reset the screen size.

Case 2, very dark. –Please use software to set the OE level.

Case 3, light on every other line. The data line is not in good contact, please reconnect it.

Case 4, some Chinese characters are displayed abnormally. – Chinese characters and symbols that are normal and not in the national standard font library.

In case 5, some areas of the screen are not displayed. Replace the cell board.