1. When testing the PCB board, pay attention to the insulating function of the soldering iron

It is not allowed to use a soldering iron to weld with electricity. It is necessary to admit that the soldering iron is not electrified, and the shell of the soldering iron should be grounded. Be more careful with the MOS circuit. It is safer to use a low-voltage circuit iron of 6~8V.

2. Before testing the PCB board, it is necessary to understand the working principle of the integrated circuit and its related circuits

Before checking and repairing an integrated circuit, you must first understand the function of the integrated circuit used, the internal circuit, the main electrical parameters, the function of each pin, and the working principle of the circuit composed of the normal voltage, waveform and peripheral components of the pin. If the above conditions are present, analysis and inspection will be much simpler.

3. It is strictly forbidden to use grounded test equipment to contact the live TV, audio, video and other equipment on the bottom plate to test the PCB without a blocking transformer.