26/06/2025
Replacing an entire LED light board can be very expensive. Did you know that 80% of failures are caused by simple problems, such as loose connections or a single LED that is damaged? Today we will learn some common phenomena that may occur after the display module is sold, learn how to find the cause and fix it, and learn basic repair knowledge to save you time and money!
For example, when the LED module has some of the phenomena shown in the figure above, a certain area is not bright or a large area is lacking color. We can use the following methods to find out the cause.
1) Check whether there is a break or short circuit between the input pin RGB signal and the 245 chip (Figures 3-9, 3-10, and 3-11 are the manifestation of the lack of a set of data)
(2) Check whether the output line between the 245 chip and the RGB driver chip is broken or shorted with other signals (such as GND, VCC, etc.). If the area is not lit, check whether the previous color driver chip has a color signal output to it and measure whether the output signal is short-circuited;
(3) Check whether the CLK clock LAT latch OE enable three signals are present from the 245 chip to the RGB driver chip, and whether there is a break during the transmission process. The regional non-lighting phenomenon (as shown in Figure 3-12) may also be related to these three signals. You can measure from the normally lit area in front or behind to the non-lit area to check whether there is a signal input:
(4) Check whether the driver chip in this area has VCC and GND signals, including the GND signal at one end of the external small resistor. When the external small resistor has no GND signal, the regional non-lighting phenomenon will also occur.
