With the continuous development of the LED display industry, LED display technology has become more mature and the scope of applications has become more and more extensive. LED display screens can be seen everywhere in commercial streets, cultural squares, and sports venues in our lives. The LED display not only brightens the landscape of the city, but also brings convenience to people's lives. Full color LED displays are roughly divided into outdoor displays and indoor displays. For example, LED displays will be applied to high-end conferences, exhibitions, radio and television, wedding hosting, stage performances, high-speed railway stations, airports and other scenes. Now that the LED display has become a part of our lives, when the full color LED display fails, how should we deal with it?
There are several methods in the repair process:
1. Voltage detection method: adjust the multimeter to the voltage range, detect the ground voltage of a certain point of the suspected circuit, and compare whether it is similar to the normal value, otherwise the fault range of the display problem can be determined.
2. Observation method. Through visual observation, open circuit is one of the problems often found with the method. It can be seen by eyes. For example, PCB circuit is open due to scratching, or open circuit caused by the electric drill.
3. Contrast method. We can't tell whether the IC is burnt out with the naked eye. You can replace it with a good IC; if you don't remember whether the signal was originally connected, we can use the unit board to measure the corresponding position to judge. The contrast method is often used in the repair process. It is very important to master this method. It allows you to quickly find out where the fault is.
4. Elimination method, a failure of the full color LED display may be caused by various reasons. We need to accurately determine each cause of the display failure, and then deal with it one by one, but it must be noted that it must be processed according to the priority level.
5. Resistance detection method: adjust the multimeter to the resistance range, detect the resistance value of a certain point of a normal circuit board, and then detect the same point of another same circuit board to test whether the resistance value is different from the normal resistance. If they are different, the scope of the problem is determined.
6. Voltage drop detection method: adjust the multimeter to the diode voltage drop detection range, because all ICs are composed of many basic single components, but they are miniaturized, so when there is a current passing through a pin of it, there will be a voltage drop across the pin. Generally, the voltage drop on the same pin of the same type of IC is similar, and whether it fails is determined according to the voltage drop value on the pin. Note: The voltage drop detection method must be operated when the circuit is powered off. This method has certain limitations. For example, if the tested device is high-impedance, it cannot be detected.
7. Short-circuit detection method. Set the multimeter to the short-circuit detection range to detect whether there is a short-circuit phenomenon on the LED display. If a short-circuit is found, it must be solved first to ensure that other devices are not burned out. Note: The short-circuit detection method must be operated when the circuit is powered off to avoid damage to the meter.