1. It is strictly prohibited to use grounded testing instruments and equipment to test the power amplifier PCB board without an isolation transformer. When coming into contact with equipment with high output power or unfamiliar with the nature of the power supply used, it is necessary to first determine whether the chassis of the machine is live, otherwise it is easy to cause a power short circuit with the live equipment on the chassis, affecting the integrated circuit, and causing the fault to expand.

2. When testing the power amplifier PCB board, attention should be paid to the insulation performance of the electric soldering iron. When testing, it is necessary to confirm that the soldering iron is not live. It is best to ground the shell of the soldering iron, and it is safer to use a low-voltage circuit iron of 6-8V.

3. It is very important to understand the working principle of integrated circuits and their related circuits before testing the power amplifier PCB board. It is necessary to be familiar with the functions, internal circuits, main electrical parameters, functions of each pin, and the working principle of each component composition circuit of the integrated circuit used. If the above conditions are met, analysis and inspection will be much easier.

4. Do not cause short circuits between pins when testing the power amplifier PCB board. When measuring voltage or testing waveform with an oscilloscope probe, it is best to measure it on a peripheral printed circuit directly connected to the pins. It should be noted that extra caution should be exercised when testing CMOS integrated circuits with flat packaging.

5. The internal resistance of the testing instrument for detecting the power amplifier PCB board should be large. When measuring the DC voltage of integrated circuit pins, a suitable multimeter should be selected, otherwise there may be significant measurement errors for certain pin voltages.

6. When testing the power amplifier PCB board, attention should be paid to the heat dissipation of the power integrated circuit. Without a heat sink, it is not allowed to operate at high power.

7. The PCB board of the power amplifier should be inspected to ensure welding quality, and it should be soldered firmly during welding. The accumulation of solder and air holes can easily cause false soldering. The integrated circuit that has been soldered should be carefully inspected to confirm that there is no solder adhesion before connecting to the power supply.

8. Do not easily determine the damage of the integrated circuit when detecting the power amplifier PCB board, and do not easily determine that the integrated circuit is damaged. Once a certain circuit is abnormal, it may cause multiple voltage changes. In addition, in some cases, when the measured voltage of each pin matches or approaches the normal value, it may not necessarily indicate that the integrated circuit is good because some soft faults do not cause changes in DC voltage.