With the popularization and application of LED advertising screens and LED full-color screens, LED advertising screens have become a beautiful landscape in today’s information society. Especially when night comes, the bright images of LED display screens make people feel the world. Colorful. However, more and more LED full-color display applications are used, and it is inevitable that such problems will occur. So how to quickly and accurately test out the LED display failure problem?

Here are four methods:

1. Resistance detection method, adjust the multimeter to the resistance mode, 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.

2. Voltage detection method: adjust the multimeter to the voltage range, detect the ground voltage of a certain point of the circuit suspected of having a problem, and compare whether it is similar to the normal value, otherwise the scope of the problem is determined.

3. Short-circuit detection method. Set the multimeter to the short-circuit detection gear (some are diode voltage drop gears or resistance gears, usually with alarm function) to detect whether there is a short-circuit phenomenon. If a short-circuit is found, it should be solved first to prevent it from burning Other devices. This method must be operated when the circuit is powered off to avoid damage to the meter.

 4. Voltage drop detection method, adjust the multimeter to the diode voltage drop detection gear, because all ICs are composed of many basic single components, but 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. According to the voltage drop value on the pin, it is necessary to operate with the circuit power off. This method has certain limitations. For example, if the tested device is high-impedance, it cannot be detected.