The problems of full-color LED display are ever-changing, so it is difficult to specifically explain which problem is in detail, so let's talk about the inspection methods and basic steps of repairing full-color LED display. If this can be mastered, I think the LED will appear at a critical moment, and the reasons can be checked from these points and the problem can be solved.
The detection methods of led display repair include short circuit detection method, resistance detection method, voltage detection method, and voltage drop detection method, so let's talk about these methods specifically.
(1) Short circuit detection method
Set the multimeter to the short-circuit detection gear (generally with an alarm function, if it is turned on, it will beep), check whether there is a short-circuit phenomenon, and solve it immediately after it is found. The short-circuit phenomenon is also the most common LED display module failure. Some can be found by observing the IC pins and header pins. The short circuit detection should be operated when the circuit is powered off to avoid damage to the multimeter. This method is the most commonly used method, simple and efficient. 90% of faults can be detected and judged by this method.
(2) Resistance detection method
Set the multimeter to the resistance range, check the resistance value of a certain point of a normal circuit board, and then check the same point of another same circuit board to test whether the resistance value is different from the normal resistance value, if it is different, it is determined The scope of the problem.
(3) Voltage detection method
Adjust the multimeter to the voltage range, detect the voltage to ground at a certain point of the suspected circuit, and compare whether it is similar to the normal value, which can easily determine the scope of the problem.
(4) Pressure drop detection method
Adjust the multimeter to the diode voltage drop detection gear, because all ICs are composed of many basic single components, but they are miniaturized, so when there is a current on one of its pins, it will exist on the pin. Voltage drop. 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 when the circuit is powered off.