Do you encounter problems of one kind or another during the use of the LED display. And still don't know how to deal with it quickly! Judging the problem must be dealt with first and lastly, and it will be treated obviously and seriously, and then dealt with small problems. (Short circuit should be priority)

1. Resistance detection method, adjust the multimeter to the resistance file, detect the resistance value of a certain point of a normal circuit board, and then test whether the same point of the same circuit board is tested and the normal resistance value is different. If it is different, the scope of the problem is determined.

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

3. Short-circuit detection method, adjust the multimeter to the short-circuit detection block (some diode voltage drop or resistance file, generally have alarm function), detect whether there is a short circuit phenomenon, and find that the short circuit should be solved first, so that it does not burn out. Other devices. This method must be operated in the event of a power failure to avoid damage to the meter.

4, the voltage drop detection method, the multimeter is adjusted to the diode drop detection file, because all ICs are composed of a basic number of unit parts, but miniaturized, so when there is current on one of its pins, There will be a voltage drop across the pin. Generally, the voltage drop on the same pin of the IC of the same model is similar. According to the voltage drop value on the pin, the circuit must be powered off. This method has certain limitations. For example, if the device under test is high-resistance, it will not be detected.