8 good ways to repair the intermediate frequency furnace

Eight good ways to repair the intermediate frequency furnace: 1. Intuitive method 2. Contrast method 3. Replacement method 4. Plug and unplug method 5. System self-diagnosis method 6. Parameter check method 7. Open circuit method 8. Short-circuit method The following is a detailed description of the specific application of these good methods in the maintenance of the intermediate frequency furnace.

  1. Specific application of intuitive method

    The intuitive method means that no instrumentation is used, and the fault is only found and analyzed according to the external performance of the intermediate frequency furnace fault. Direct observation includes no power check and power on observation. In the overhaul, first check the non-energization, use the human sensory organs (eyes, ears, hands, nose) to check for loose plugs, poor contact, solder joints, open circuit, short circuit, component rust, zoom, discoloration and fuses. Melt blowing and other phenomena. The intuitive method is the most basic and simple method. The maintenance personnel can reduce the fault to a certain module by observing and checking various abnormal phenomena such as light, sound and taste generated when the fault occurs. The board even goes to a component. However, it requires maintenance personnel to have a wealth of practical experience.

    Before performing the visual inspection, the user and the fault presence personnel should be inquired about the situation, including the external performance of the fault, the approximate location, the environmental conditions at the time of the fault, whether there is abnormal gas, open flame, whether the heat source is close to the intermediate frequency furnace, and whether there is corrosive gas. Intrusion, whether there is water leakage, whether someone has repaired and repaired the contents.

    In the implementation process of the intuitive method, we should adhere to the principle of simplicity, complexity, and externality. In actual operation, the first is to obtain the random technical data of the intermediate frequency furnace, and the second is to shape, name, representative letters, circuit symbols and functions of various electronic components in the disassembled intermediate frequency furnace. For the upper number, the electronic components can be accurately identified. When using the intuitive method of maintenance, it is mainly divided into the following three steps.

    (1) External inspection. Before repairing the intermediate frequency furnace, first observe whether the buttons, sockets, and external connections on the intermediate frequency furnace are damaged.

    (2) Internal inspection. Observe whether the melt of the fuse is blown, whether the components touch, disconnect, change color, whether the circuit board is plugged reliably, whether there are loose parts and discoloration on the circuit board, whether the copper foil and solder joints are good, whether there is any maintenance Over. When inspecting the internal frequency of the intermediate frequency furnace, some components, components, and circuit boards can be moved by hand to fully check.

    (3) Inspection after power-on. After the medium frequency furnace is energized, the eyes should see whether there is any fire or smoke inside the intermediate frequency furnace; the ear should have an abnormal sound inside the intermediate frequency furnace; the nose should smell the burnt smell inside the intermediate frequency furnace; the hand should touch some transistors and integrated circuits. Whether it is hot (should be safe, avoid causing personal and equipment accidents), if there is abnormal heating, it should be shut down immediately.

    The intuitive method is very simple, does not require other instruments and meters, and is effective for overhauling general faults and damaged faults of intermediate frequency furnaces. Intuitive method detection is more comprehensive, and it is closely related to the maintenance personnel's experience, theoretical knowledge and professional skills. Intuitive methods need to accumulate experience in a large number of overhaul practices in order to be skilled. Intuitive method testing often runs through the entire process of repair, and works better with other test methods.

    2. Contrast method specific application

The contrast method is a method of finding the cause of the fault by comparing the normal feature with the wrong feature. When there is a problem in a certain unit circuit of the intermediate frequency furnace, the parameters of the unit circuit and the parameters of the normal unit circuit with the same working state can be used. (such as theoretical analysis of current, voltage, waveform, etc.) for a comparison. This method is most suitable when there is no circuit schematic diagram, that is, by comparing the test data with the drawing data and the normal parameters of the usual records to judge the fault, and there is no data and no flatness.

  The medium frequency furnace recorded at the time can be compared with the intact medium frequency furnace of the same model, and the abnormal condition in the unit circuit can be found out, and then the cause of the fault can be analyzed, and the fault point can be judged. The comparison method can be an analogy of the same unit circuit itself, or It is a comparison of a faulty board with a known board, which helps maintenance personnel quickly narrow down the fault check.

    3. Replacement method specific application

    The replacement method is to replace a suspected and inconveniently measured electrical component or circuit board on a faulty intermediate frequency furnace with an electrical component or circuit board of the same specification and good performance, thereby judging a fault detection method. Sometimes the fault is more concealed. The cause of the failure of some circuits is not easy to determine or when the length of the inspection is too long, it can be replaced by components with the same specifications and good type. In order to narrow down the fault range, go to the next step to find the fault and confirm whether the fault is caused by this component.

When using the replacement method, it should be noted that when the electrical components or circuit boards suspected to be faulty on the original intermediate frequency furnace are removed, the external circuits of the electrical components or circuit boards should be carefully checked, only when the peripheral circuits are normal. Replace with new electrical components or boards to avoid damage after replacement.

    In addition, due to the fault state of some components (such as capacitor capacity reduction or leakage, etc.) can not be determined with a multimeter, then should be replaced with genuine or connected to the genuine device to see if the fault phenomenon has changed. If the capacitor insulation is suspected to be poor or short-circuited, the end must be disconnected during the test. When replacing components, replace the components as much as possible with the damaged component specifications.

    When the fault analysis results are concentrated on a certain printed circuit board, it is very difficult to implement the fault on a certain area or even an electrical component due to the continuous integration of the circuit, in order to shorten the fault inspection time. In the case of the same spare parts, you can replace the spare parts first, and then check the repaired fault board. Pay attention to the following issues when replacing spare parts.

    (1) Replacement of any spare parts must be carried out in the event of a power failure.

    (2) Many printed circuit boards have some setting switches or shorting bars to match the actual needs. Therefore, it is necessary to record the original switch position and setting state and the connection mode of the shorting bar on the replacement spare parts. The new board will do the same, otherwise an alarm will be generated and the unit circuit will not work properly.

    (3) Some printed circuit boards need to perform certain operations after replacement to complete the establishment of their software and parameters. This requires careful reading of the instructions for the appropriate board.

    (4) Some printed circuit boards cannot be easily pulled out, such as boards containing working memory, or have spare battery boards. Pulling out will lose useful parameters or programs. Follow the instructions when replacing.

    (5) It is strictly forbidden to use the replacement method on a large scale. This will not only achieve the purpose of repairing the faulty intermediate frequency furnace, but will even advance.

Expand the scope of the fault in one step.

    (6) The replacement method is generally used when there is significant doubt about a component after the application of other detection methods.

    (7) When the electrical components to be replaced are at the bottom, the replacement method should also be used with caution. If it must be used, it should be fully disassembled to expose the components, and have sufficient operation space for easy replacement.

    Using a spare board of the same type to confirm the fault is a very effective way to narrow the inspection range. The problems of the control board, power board and trigger board of the intermediate frequency furnace can often only be replaced. There is no other way, because most users will hardly get the schematic and layout, which makes it difficult to achieve chip-level maintenance.

    In view of the above conditions, before replacing the old circuit board and replacing the new circuit board, be sure to read the relevant information carefully, and then understand the requirements and operating procedures before hands-on, so as to avoid further failure. The replacement method is more accurate in determining the cause of the failure, but it is cumbersome to operate, sometimes difficult, and has some damage to the board. Therefore, the use of the replacement method depends on the intermediate frequency, the specific situation of the power failure, and the difficulty of the existing spare parts and replacement of the maintenance personnel. In the process of replacing electrical components or circuit boards, the connection should be correct and reliable, and do not damage other components around it, so as to correctly judge the fault and improve the maintenance speed, and avoid artificial failure.

If you suspect that the two-pin components are broken during maintenance, you do not need to remove them. Instead, solder a component of the same specification on the component of the board. After the soldering, the fault disappears. The suspected component is open. Then cut off the faulty components. When it is suspected that the capacity of a capacitor is reduced, it can also be judged by direct parallel connection.