The problems of LED display screens are also ever-changing, so it is not easy to explain which problem in detail, so let’s talk about the detection methods and basic steps of maintenance of full-color LED display screens. If this can be mastered, I think that when the LED is in a critical moment, the cause can be checked from these points and the problem can be solved.

The detection methods of led display maintenance include short circuit detection method, resistance detection method, voltage detection method, and voltage drop detection method, so let’s talk about these methods in detail.

(1) Short circuit detection method

Set the multimeter to the short-circuit detection gear (generally has an alarm function, if it is turned on, it will beep), check whether there is a short-circuit phenomenon, and solve it immediately after the short-circuit 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 pin headers. 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

Adjust the multimeter to the resistance level, detect the resistance value of a certain point of a normal circuit board to the ground, and then test the same point of another same circuit board to see if it 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 level, 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, which can conveniently 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 units, but they are miniaturized, so when there is current passing through a certain pin of it, there will be a voltage 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 is better or worse, and it must be operated when the circuit is powered off.