Before electrifying, the appearance and insulation performance must be checked, and it can be electrified only after it is confirmed to be qualified. (3)

After electrifying, check transformers, motors, transistors, integrated circuits, etc. Whether it is overheated or not, and whether the rotating parts are noisy. If abnormal phenomena are found, the power supply should be cut off immediately and the reasons should be found out. (4)

During maintenance, you should be familiar with the circuit principle and circuit of this machine, and use instruments and drawings to check the working parameters and voltage waveforms of power supply, rectifier filter circuit, transistor and other components according to certain procedures. Don't disassemble or disassemble the parts without finding out the reason, and don't burn the parts easily. It is necessary to analyze the possible causes of the fault from the fault phenomenon and find out the fault point.