LED显示屏维修的检测方法
Detection method for maintenance of LED display screen
第一短路检测法：将万用表调到短路检测挡（一般具有报警功能，如导通则发出鸣叫声），检测是否有短路的现象出现，发现短路后应马上解决，短路现象也是最常见的LED显示屏模块故障。有的通过观察IC引脚和排针引脚就能发现。短路检测应在电路断电的情况下操作，避免损坏万用表。这个方法是最常用到的方法，简单、高效。90%的故障都可以通过这个方法检测判断。
The first short circuit detection method: the multimeter is transferred to the short circuit detection gear (usually with the alarm function, such as the guiding principle sends out the chirp), the detection whether there is the phenomenon of short circuit, the short circuit should be solved immediately after the short circuit, the short circuit phenomenon is also the most common LED display module fault. Some can be detected by observing the IC pin and pin pin. Short circuit detection should be operated in the case of circuit power failure to avoid damaging the multimeter. This method is the most commonly used method, simple and efficient. 90% of faults can be detected by this method.
第二电阻检测法：将万用表调到电阻档，检测一块正常的电路板的某点的到地电阻值，再检测另一块相同的电路板的同一个点测试与正常的电阻值是否有不同，若不同则就确定了问题的范围。
Second resistance detection method: adjust the multimeter to the resistance gear, detect the ground resistance value of a certain point of a normal circuit board, and check whether the same point of the same circuit board is different from the normal resistance value. If the difference is different, the range of the problem is determined.
第三电压检测法：将万用表调到电压档，检测怀疑有问题的电路的某个点的到地电压，比较是否与正常值相似，可以方便的确定问题的范围。
Third voltage detection method: transfer the multimeter to the voltage file, detect the ground voltage of some point of the doubted circuit, whether it is similar to the normal value, and can easily determine the scope of the problem.
第四压降检测法：将万用表调到二极管压降检测档，因为所有的IC都是由基本的众多单元件组成，只是小型化了，所以在当它的某引脚上有电流通过时，就会在引脚上存在电压降。一般同一型号的IC相同引脚上的压降相似,LED照明灯，根据引脚上的压降值比较好坏，须在电路断电的情况下操作。
Fourth pressure drop detection method: adjust the multimeter to the diode voltage drop detection gear, because all IC is made up of a large number of basic components, only miniaturized, so there is a voltage drop on the pin when a current is passed on one of its pins. Generally the same type of IC on the same pin voltage drop is similar, LED lighting, according to the pin voltage drop value is better or worse, must operate in the case of circuit power off.