1. CLK clock signal: the shift pulse provided to the shift register, each pulse will cause data to be shifted in or out one bit. The data on the data port must be coordinated with the clock signal to transmit data normally, and the frequency of the data signal must be the clock signal 1/2 times the frequency. In any case, when the clock signal No. 1 is abnormal, it will make the whole board display messy.

2. STB latch signal: send the data in the shift register to the latch, and display the data content through the drive circuit to light up the LED. However, since the drive circuit is controlled by the EN enable signal, the premise of its lighting must be the enable state. The latch signal also needs to be coordinated with the clock signal to display a complete image. In any case, the When there is an abnormality in the latch signal, it will cause the display of the board to be chaotic.

3. EN enable signal: the whole screen brightness control signal, also used for screen blanking. Just adjust its duty cycle to control the change in brightness. When the enable signal is abnormal, the whole screen will appear dark, dark or trailing.

4. Data signal: Provide the data needed to display the image. It must be coordinated with the clock signal to transmit data to any one of the display points. Generally, the data signals of red, green and blue are separated in the display screen. If a data signal is short-circuited to the positive or negative pole, the corresponding color will appear full on or off. When the data signal is empty, the corresponding color will appear. Display is uncertain.

5. ABCD line signal: only in the dynamic scanning sensitive display, ABCD is actually a binary number, A is the lowest bit, if the ABCD signal is expressed in binary, the control address is 16 lines (1111), 1/4 scan As long as the AB signal is enough, because the representation range of the AB signal is 4 lines (11). When the line control signal is abnormal, there will be display dislocation, highlight or image overlap.