Quickly repair electronic circuits and techniques
Today's society, whether it is home appliances, broadcasting and communications equipment, computers, machine tool equipment control, electronic instruments, as well as medical equipment and so on are inseparable from the use of electronic circuits. The following is my compilation of methods and techniques of rapid repair of electronic circuits, we take a look at it.
Today's society, whether it is home appliances, broadcasting and communications equipment, computers, machine tool equipment control, electronic instruments, and medical equipment and so on are inseparable from the use of electronic circuits. In the long-term use of the process, due to the manufacturing process, the quality of components, as well as device life and other issues, a variety of electronic circuits will produce such and such a failure. How to repair a variety of electronic circuits in the shortest possible time to ensure that the normal use of products and machine tools and instruments, has been the majority of maintenance personnel to explore, and constantly pursue the goal. Moreover, the general maintenance staff is more specialized, repair of home appliances, only repair of home appliances, repair machine tool control circuits, only repair machine tool control circuits and so on. In fact, to master some of the basic knowledge of the repair of electronic circuits, the future can also expand the field, a variety of circuit maintenance, both to create economic benefits, but also to create social benefits. According to engage in many years of home appliance instrumentation and machine tool control circuit repair experience, in this **** with the discussion of some electronic circuits fast repair methods and techniques.
First, the rapid repair of electronic circuits
1. Clearly the function of the electronic circuit, regardless of any electronic circuit, in the maintenance of the function before it must be clear that the role of the function, only then as soon as possible to proceed to the next step of the repair work.
2. Determine the resulting failure phenomenon according to its functional role, to determine the resulting failure phenomenon.
3. Analyze the working principle of the electronic circuit to determine the scope of the fault. Familiarize yourself with the working principle of the maintenance circuit, starting from the block diagram. The role of the block diagram of the whole machine has two, one, showing the connection between the parts, and the other, clear parts of the circuit in the whole machine (the whole circuit) plays a role. Then determine the scope of the fault. For example: in the television, field oscillation circuit, field excitation circuit, field output circuit, one of the circuit failure, will lead to frame one line of this fault phenomenon, it is certain, inevitable. Conversely, the frame line failure of the television set, it is possible to produce a fault is the part of the field oscillator circuit, field excitation circuit, field output circuit, which is the possibility, not the inevitability. In the judgment to develop a reversible thinking, try not to miss the possibility.
4. The use of some repair methods to determine the part of the fault, to find the point of failure, troubleshooting to determine the scope of the fault, you must be through some of the inspection methods to produce the possibility of failure one by one to rule out the possibility of failure, to find the real part of the failure (cause), and ultimately to find the point of failure, troubleshooting.
5. Practical inspection methods (1) intuitive method of possible failure of the parts, do not rush to measure, etc., the first to carefully observe, to see if there are no traces of failure. For example,
Are there any burnt components, whether the wire is off, whether the fuse is blown and so on. Doing so, such as the discovery of the above problems, can save a lot of time, less detour. (2) In-circuit resistance measurement method using a mechanical meter, should not use a digital meter. Use a low resistance block to measure the resistance to ground of the ` each output of AC and regulated DC power supplies to check whether the load of these power supplies has a short circuit or leakage. In the absence of, the power supply can be turned on, the next step in the repair. (3) current measurement judgment method in series in the circuit to measure, generally measure the whole machine current, to determine whether the load has a short circuit (overload). (4) voltage measurement judgment method of the suspected part of the circuit of the DC static working point voltage measurement, according to the measured value and the known value of comparison, through logical reasoning, and finally determine where the fault lies. (5) instrument detection method some faults in the case of difficult to repair with a multimeter, the use of some electronic instrumentation, such as: oscilloscopes, signal generators, etc., mainly used for the detection of oscillating circuits, the detection of the AC channel as well as a specific point of the waveform detection and so on.
Second, some of the skills of rapid repair of electronic circuits
1. Some simple electronic circuit repair skills (1) first check whether the power supply is normal, and then check the integrated circuits and tubes of the power supply is normal. (2) there are integrated circuits can be replaced with alternative methods, if not normal and then check the peripheral components. (3) there are oscillating circuits, oscilloscopes or multimeters can be used to determine whether the first oscillation before repair.
2. All the functions are not the fault of the maintenance skills (1) should first start checking the power supply from the circuit work. (2) the power supply is not faulty, then check the remote control or CPU control startup circuit. (3) check whether the protection circuit is working, if the work should be disengaged first, and then check.
3. Some electronic equipment, computers and machine tool control circuits repair skills some electronic equipment, computers, and machine tool control circuits are more complex, but they are divided into very clear circuit, the function of each part of the circuit is also very clear, and the different functions of the circuit is mostly composed of different circuit boards, the entire circuit using contact connections.
In these aspects of the maintenance, in order to save time can be faulty circuit board replacement, which is also a fast way to repair some equipment manufacturers. Eventually free up time to repair the faulty board for next time.
4. PLC and microcontroller control circuit repair skills (1) first to determine whether the power supply is working properly. (2) according to the loss of function or action, from the control of this function or action of the circuit of the last level step by step forward to check. (3) The final check to the CPU output interface, if not normal, then check the CPU circuit and programming error.
5. No technical information on the circuit maintenance skills (1) in the absence of drawings and other technical information, the maintenance of such circuits, you should first turn off the power supply, the use of on-line resistance measurements, the first detection of a number of vulnerable components. For example: starting resistor, current limiting resistor, insurance resistor, electric wire, coil, transistor, diode and so on. (2) Turn on the power supply, check whether it works. (3) The power supply is normal, detect the DC static operating point voltage of each tube and integrated circuit. (4) If there is an AC output function, the AC voltage block of the multimeter can be used to measure the output, if so, the output load open circuit. Now the development of electronic technology is changing rapidly, to continue to learn and communicate. Improve the mastery of a variety of modern electronic technology, to better serve the community, to create a double harvest of economic and social benefits.
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