With the popularization and application of LED electronic display screen and led full-color screen, LED display has become a beautiful landscape in today's information society, especially when the night comes, the LED display displays a bright picture, so that people can feel the colorful world. However, with the continuous expansion of the application scope of LED display, LED display has more and more fault problems, so how to test the fault of LED display screen? The following is a brief introduction from LED display manufacturers.

1. In resistance detection method, the multimeter is adjusted to the resistance gear, and the resistance value to ground of a certain point of a normal circuit board is detected, and then the same point of another same circuit board is detected to test whether the resistance value is different from the normal resistance value. If different, the range of the problem is determined.

2. In the voltage detection method, the multimeter is adjusted to the voltage position, and the voltage to the ground at a certain point of the suspected circuit is detected, and whether it is similar to the normal value is compared, otherwise, the range of the problem is determined.

3. In the short circuit detection method, the multimeter is adjusted to the short circuit detection gear (some are diode voltage drop or resistance gear, generally with alarm function) to detect whether there is a short circuit. If a short circuit is found, it should be solved first to avoid burning other devices. This method must be operated in the case of power failure to avoid damaging the meter.

4. The voltage drop detection method is to adjust the multimeter to the diode voltage drop detection file. Because all IC is composed of many basic single components, it is only miniaturized, so when there is current passing through a pin, there will be a voltage drop on the pin. Generally, the voltage drop on the same pin of the same type of IC is similar. According to the voltage drop value on the pin, it must be operated under the condition of power failure. This method has some limitations, such as the device to be detected is high resistance, it can not be detected!