Circuit board maintenance is actually an experience. You want to quickly find fault points from dense components. Not only do you need extensive maintenance experience, but you also need to know the working principle of the board. The following small series are based on your own knowledge. Method Try to talk about how to quickly lock the faulty component. If there is an error, please criticize it.
How to quickly lock faulty components in circuit board repair
First, find out the functional circuit where the fault is located. Any complex circuit is composed of a variety of functional circuits, such as power circuits, signal processing circuits, output circuits, etc., according to the fault phenomenon to determine which part of the circuit is a problem. For example, if the device has no power, we will definitely check the power circuit part first, so that the faulty components are locked in a certain range.
Second, secondly, the voltage method is used to further reduce the fault range. No matter what faults in the circuit, the final working state is expressed in the form of voltage. At this time, the key point voltage needs to be measured with a multimeter or an oscilloscope. We still use power supply circuit as an example. Most of the electronic devices now use switching power supply as the power supply, and most of them are integrated, and there are few peripheral components. We only need to measure the pin voltage of the integrated chip and compare the correct value to make the fault. The scope is further narrowed. (Sometimes the chip is more likely to be damaged than the peripheral components)
Third, in the end, the components that are suspected are measured one by one. After the above two steps, we have reduced the fault range to a certain extent. The following only need to measure the components suspected one by one, and some small patch components can also be directly replaced.
In summary, the most critical step in rapid maintenance is to use the voltage method to determine the fault range. This requires a certain understanding of the circuit principle of the whole machine. Only in this way can the fault be judged according to the voltage state of the measuring point, so if you want to do To quickly lock faulty components, the most important thing is to be able to read the schematic diagram, master the foundation to easily face a variety of faults, otherwise it can only be “practice boxing does not practice, to the old one.”