How to deal with the circuit failure of the hottes

How to deal with instrument circuit failure

circuit failure is inevitable for instruments. In the application of instruments, learning and mastering some necessary fault detection and maintenance methods can not only improve the production efficiency, but also save the time waiting for maintenance and reduce the maintenance cost. Today, we will summarize the common instrument circuit fault detection and response methods

observation feeling method

this is the simplest and most direct method, which directly judges the cause of the fault by relying on the senses. Generally, the color of damaged components will change, and there will be bubbles or burnt spots; Burned out devices will produce some special smells; Short circuit chips will burn; The appearance can also be observed with the naked eye, such as circuit board wiring, broken wires, copper foil damage, device cracking, fuse fusing, etc; Touch by hand to check whether the components are loose, whether the integrated circuit is firmly inserted, whether the battery, resistance, integrated block is hot, etc; You can also hear or smell whether there is abnormal sound and smell. These phenomena are abnormal

knocking and hand pressing

when instruments and meters are running, they often run in good times and bad times. When this kind of fault occurs, it is first considered that it is caused by faulty welding, poor contact and other reasons. In view of this situation, knocking and hand pressing methods can be used. Tapping method refers to gently tapping the connector. If the instrument and meter of the jaw clamping plate of the screen display hydraulic universal testing machine breaks down regularly during normal operation, or it turns normal after knocking, then it can be judged that the connector is faulty. The manual pressing method is to press the components and plugs and sockets firmly by hand after turning off the power when the fault occurs, and then turn on the machine to see whether the fault will be eliminated. If it is found that it is normal when pressing the housing, and it is abnormal after loosening, it is best to plug all connectors firmly and try again

static before dynamic method

static before dynamic should be used to check the working state of the circuit. Here, static refers to DC working and static working conditions, and dynamic refers to dynamic conditions. Generally, it is required to observe whether the static working condition is normal first, and then check the dynamic working condition when the static working condition is good

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replacement method

if the cause of the fault is complex, you can judge the possible location of the fault according to experience, and then use the same and normal plug-in board or good components, especially integrated circuits and modules, to replace the plug-in board or components with suspected faults to test the fault and see whether the fault is eliminated. The replacement method requires two instruments of the same model or sufficient spare parts

elimination method

in the detection methods of electronic instruments, elimination method is also a frequently used method. Elimination method is usually used in detection and use, and it can eliminate the faults one by one. Its main advantage to ensure the normal operation of the experiment is that it can save a lot of time, and it can eliminate the faults in complex faults in a more accurate and timely manner, The disadvantage of being able to solve the faults in the shortest time is that in the early work, we must be careful, otherwise it is difficult to use this method well, which can not only save time, but also waste a lot of time, and can not achieve the desired effect. The so-called troubleshooting method is to determine the cause of the fault by pulling and plugging some plug-in boards and devices in the machine. When the instrument returns to normal after unplugging a plug-in board or device, it indicates that the fault occurred there

comparison method

select two instruments with the same model, one of which is normal. Use table, oscilloscope, etc. 2 The refrigeration system has overheating tools to measure the data, and compare and analyze the voltage and output results. The two instruments operate under the same conditions, detect the corresponding signals, and compare the measured two groups of signals. If they are different, the source of the fault can be determined

voltage measurement method

in the normal working process of the instrument, its working voltage has a stable value or a certain range of change. If the open circuit and short circuit exist in the circuit, it will change the working voltage of the circuit or cause the parameters of components to change. Therefore, the voltage measurement method can be used to measure the voltage of key points in the circuit, through the phenomenon of fault, and make fault analysis according to the working principle of the instrument

artificial fault method

in the detection of commonly used electronic instruments, the subjective method of detection is a commonly used method. In addition to being affected by objective methods, this subjective method is also a relatively popular detection method. Generally speaking, it is to set some faults artificially, and achieve the purpose of detecting electronic instruments by setting the faults yourself. This method refers to artificially creating some faults in the circuit, such as disconnecting an important device, checking whether the circuit before it is normal, shorting a part, and checking whether other parts are normal