1. Want it? There is a dead drawing in my head, and the thoughts in my head are alive, which can be analogized, reasoned, extrapolated and learned. For example, switching power supply is always inseparable from oscillating circuit, switching tube and switching transformer. Check whether the circuit starts to vibrate, whether the capacitor is damaged, and whether the transistor and diode are damaged. No matter what switching power supply you encounter, it is almost the same to operate. There is no need to force a circuit diagram, such as a single chip microcomputer system, including a crystal oscillator, three buses (address line, data line and control line) and an input/output interface chip for maintenance. Virtual short? And then what? Vacation? On the basis of reasoning, we can also make a detailed analysis and make it clear. After practicing analytical reasoning skills, even if you encounter equipment that you have never seen before, you only need to understand it in principle.

2. Pay attention to the maintenance sequence. Only by paying attention to the maintenance sequence can we find the shortest path to solve the problem and avoid disorderly stabbing and dismantling. Failure in maintenance will lead to the expansion of the fault. Maintenance is like a doctor treating a patient. Should we pay attention to it? Looking forward to it? . ? Hope? That is, check the appearance of the fault board to see if there are obvious damage marks on it, whether there are black and cracked components, whether there is circuit leakage caused by corrosion, whether there is capacitor leakage, and whether there is protrusion at the top. ? Smell? If something is burnt, smell it with your nose and see where the smell comes from. ? Ask? It is very important to ask the parties in detail about the situation when the equipment breaks down and infer the parts or components that may break down according to the situation; ? Cut? That is, using certain test instruments and means to check resistance, voltage, waveform, etc. Circuit parts or components, better and worse circuit boards, differences in observation parameters, etc. In fact, you have solved many faults without using a multimeter, and the circuit diagram is naturally free.

3. Be good at summing up laws. Generally, after accumulating certain maintenance experience, you should be good at summarizing and analyzing the causes of damage to various components, which is improper operation? Lack of maintenance? Unreasonable design? Poor component quality? Natural aging? With these analyses, the next time you encounter a similar fault, although it is not the same circuit board, you will feel a little relieved. 4. Be good at finding information. Since the advent of the Internet, it has become very easy to find information. Do not understand the principle of equipment, do not understand the principle of circuit, almost all can be found from the Internet, any IC information can be found from the Internet. It used to be said that a master takes an apprentice, and whether the apprentice learns well depends on whether the master has a heart or not. Now you don't have to. With the internet, your experts are all over the world, and there are all kinds of experts.

5. Necessary testing equipment. If you take maintenance as your career, then a certain amount of equipment investment is necessary. Electric soldering iron, multimeter, commonly used disassembly tools, not too bad brand.