Many of the Front Service LED Display faults are caused by improper installation, so the installation of the Front Service LED Display requires strict steps, especially when installing for the first time, which can reduce errors.
1. Check the Front Service LED Display supply voltage
Locate the Front Service LED Display DC positive and negative connection switch power supply, connect the 220V power cable to the switching power supply (after confirming that the connection is correct, connect to the AC or NL terminal) and plug it in. You will find that there is a light on the power supply, then use a multimeter, DC to measure the voltage between V+ and V-, to ensure that the voltage is between 4.8V-5.1V, there is a knob next to it, you can adjust the voltage with a Phillips screwdriver. In order to reduce the screen heating and prolong the life, the voltage can be adjusted to between 4.5V and 4.8 when the brightness is not high. After confirming that there is no problem with the voltage, disconnect the power supply and continue assembling other parts.
2. Connect the Front Service LED Display power supply
First turn off the Front Service LED Display, connect V+ to the red line, V- to the black line, and connect to the control card and LED unit board respectively. The black line is connected to the control card and the GND of the power supply. The red line connects the +5V of the control card to the VCC of the cell board. 1 power cord per cell board. When you are done, check to see if the connection is correct.
3. Connect the Front Service LED Display Control and Unit Board
Connect the cable with the Front Service LED Display. Pay attention to the direction, you can't reverse it. Note that the cell board has two 16-pin interfaces, one for input (in) and one for output (out). The input near 74HC245/244 is the input that connects the control card to the input. The output is connected to the input of the next cell board.