Electrons are clear, so learn the unit circuits of electrons and the principles of various electrical appliances. The schematic diagrams of various household appliances are composed of unit circuits. Go to the maintenance department for an internship if possible.
2. What is the professional course of home appliance maintenance?
Electronic appliance application and maintenance major, that's what I learned.
There are many subjects, such as: electrical and electronics, home appliance fault maintenance, PLC, mold drawing, electronic drawing. ......
3. Small household appliances after-sales maintenance process
Let's find someone who knows how to repair it.
4. What should I learn about home appliance maintenance?
Electrical maintenance is the most basic application of radio specialty and the most practical aspect of this subject. Everyone who loves radio usually does some maintenance work, at least it is to repair the minor faults of the electrical appliances around him.
Steps/methods
direct-vision method
1. principle
Intuitive method is a maintenance method to find and eliminate faults through human eyes or other sensory organs.
2. Application
Intuitive method is the most basic test reason.
One of the methods of obstacles, the implementation process should adhere to the principle of simple before complex, external before internal. In practice, the first problem is how to open the cabinet. Secondly, the shapes, names, representative letters, circuit symbols and functions of various electronic components in disassembled electrical appliances can be numbered in pairs. That is, electronic components can be accurately identified. As an intuitive method, inspection mainly has two aspects: one is the observation of physical objects; The second is the observation of the image. The former is suitable for various maintenance occasions, while the latter is mainly used for video equipment with images, such as TV sets.
Visual maintenance is mainly divided into the following three steps:
(1) Inspection before unpacking: Observe the appearance of electrical appliances to see if there are any collision marks, and whether the buttons, sockets and wires of electrical equipment on the machine are damaged.
(2) Inspection after opening the case: observe the circuit board and various devices in the machine to see if the fuse is blown; Whether there is any component collision or disconnection; Whether the resistor is burnt out or discolored; Whether the electrolytic capacitor has leakage, crack and deformation; Whether the copper foil and solder joints on the printed circuit board are intact, whether there are traces of trimming and welding by others, etc. When observing in the machine, you can move some parts by hand in order to check them comprehensively in an intuitive way.
(3) Check after electrifying: At this time, it depends on whether there is fire or smoke inside the electrical appliance; Ears should listen to whether there is abnormal sound inside the appliance; Sniff whether there is coking smell inside the electrical appliance; Contact with some pipes, integrated circuits, etc. See if they are hot. If there is abnormal fever, turn it off immediately.
3. A few notes
(1) The intuitive method is very simple and does not need other instruments. It is very effective for repairing common faults and damaged faults of electrical appliances.
(2) The intuitive detection method is comprehensive and closely combined with the experience, theoretical knowledge and professional skills of maintenance personnel. Mastering it skillfully requires a lot of practice.
(3) Visual inspection often runs through the whole repair process, and it is better to cooperate with other inspection methods.
Resistivity method
1. principle
Resistance method is a maintenance method to judge the fault by measuring the grounding resistance of integrated circuit, transistor pin and electrical unit circuit and the resistance of each element.
2. Application
Resistance method is one of the most basic troubleshooting methods. Generally speaking, there are two methods of resistance measurement: "online" resistance measurement and "off-welding" resistance measurement.
Measuring resistance "on-line", because the tested components are connected in the whole circuit, the resistance measured by multimeter will be affected by other parallel branches, so it should be considered when analyzing the test results to avoid misjudgment. The normally measured resistance will be equal to or less than the actual marked resistance of the component, and it is impossible to have a resistance greater than the actual marked resistance. If so, the component under test is faulty.
"Soldering" resistance measurement, because one end or the whole component is soldered from the printed circuit board, and then the resistance is measured with a multimeter, this method is troublesome to operate, but the measurement result is accurate and reliable.
(1) switchgear detection
There are many switching elements in various electrical appliances, and measuring their contact resistance and disconnection resistance is the most commonly used means to judge the quality of switching elements. The contact resistance of the on-line resistance measuring switch should be less than 0.5 Ω, otherwise it is poor contact. It is normal that the disconnection resistance should usually be greater than several thousand ohms.
(2) Quality inspection of components
Resistance method can judge the quality of resistance, capacitance, inductance coil and transistor.
When using resistance method, the resistance value of online resistance is generally tested first. After measuring the resistance of each component, the red and black bars of the multimeter should be exchanged once, and then the resistance should be measured again. This can eliminate the interference of external circuit network on the measurement results. The results of two resistance tests should be analyzed for reference. Key suspicious parts can be desoldered for further inspection.
(3) On-off detection of connectors
There are many connectors in electrical appliances, such as earphone sockets, power conversion sockets and various plug-ins on circuit boards, which can be tested by resistance method. For example, the contact resistance can be detected by inserting and unplugging the plug of the round hole socket. When testing other plug-in components, the contact resistance can be measured by swinging the connector. If the resistance value is uncertain, there is a poor contact fault.
3. A few notes
(1) resistance method is very effective for troubleshooting open circuit or short circuit faults. In testing, online testing is often used first. After problems are found, components can be removed before testing.
(2) On-line testing must be carried out in the case of power failure, otherwise the measurement results will be inaccurate and the multimeter will be damaged.
(3) When testing some integrated circuits with low voltage (such as 5V and 3V), don't use the R× 10k multimeter to avoid damaging the integrated circuits.
(4) When testing the quality of components online by resistance method, the red and black bars of the multimeter should be tested interchangeably to avoid the influence of external circuits on the measurement results.
5. Explain that small household appliances are completely proficient in maintenance (two-color version). Extension of portable document format file (abbreviation of portable document format)
The working principle is clear. As for the fault maintenance attack, only by fully mastering the principle and the functions of each component can the fault be quickly maintained and judged. I used to study maintenance electrician with a certificate, and then I studied elevator optical principle for 3 years. So, generally speaking, I have to find out the function of each component within 2 minutes, and what is the fault performance of each component?
6. Basic knowledge of home appliance maintenance
In the home appliance industry
Refrigeration equipment is relatively simple.
We can start with refrigeration equipment.
Theory plus practice
Television is more complicated.
Need better theoretical knowledge
or
Even if you fix the TV.
I don't know what happened
I suggest reading more books.
7. Do I need to take a circuit class to learn home appliance maintenance?
Li Leiwang believes that,
First of all, you must be able to find information about this company. If you can't get back his information, you must be an impostor.
Secondly, we should also be cautious about those that are ridiculously cheap, because if they are too cheap, there is the possibility of adding money in the middle.
Then, we must discuss with the training institution in advance, and it is best to pay according to the contract.
Finally, if you want to optimize and promote the network of training institutions, please find Li Lei Network.
8. What courses do you need to study for home appliance repair?
Maintenance has now become an important major, mainly aimed at the maintenance management of ordinary household appliances, mainly studying the basics of electronics and electricians, home appliance maintenance, refrigeration installation and maintenance, and high-end home appliance maintenance. This major has also solved the re-employment problem of some unemployed workers.
main content
1. The basic part of electrotechnics and electronics mainly studies electrotechnics principles, electronic circuits, integrated circuits, analog electronic circuits, radio transmission and reception, and rapid maintenance technology.
2. The home appliance maintenance part mainly studies electronic basics, radios, amplifiers, stereos, washing machines, audio equipment, black and white, ordinary color TVs and remote control circuits; Installation, principle and maintenance technology of solar water heaters, induction cookers, CDs, VCDs, DVDs, power amplifiers, electric fans, smart appliances and other household appliances.
3. In the part of refrigeration installation and maintenance, I mainly study electrician foundation, transistor circuit, refrigeration principle and fault maintenance, refrigerator, air conditioning refrigeration, refrigeration equipment, electrical appliances and control circuit principle, the use of refrigeration tools, the analysis and operation of refrigerator air conditioning circuit, the fault analysis, practical operation and installation technology of air conditioning, refrigerator, freezer and central air conditioning.
4. The maintenance part of high-grade color TV and flat-panel TV mainly studies the principle and maintenance of large-screen color TV unit circuit; Principle and maintenance of rear projection color TV unit circuit: basic knowledge of digital circuit and HDTV; Principle and maintenance of digital HDTV circuit: principle and maintenance of LCD TV: principle and maintenance of plasma TV: introduction of LED TV principle; Use of high-grade instruments and meters ...
9. Where can I go for home appliance maintenance training?
Guangzhou Weihexiang Technical Training School is very good. If they want to open a shop after school, they have category C home appliances, including: air conditioning maintenance+refrigeration (refrigerator, freezer), color TV+new home appliances, LCD TV advanced maintenance, LCD screen maintenance advanced class. The teacher has more than ten years of teaching experience, and the course is mainly practical. After graduation, you can get a job or help open a shop, or you can take the national authority certification. If you are in Guangzhou, I suggest you go on a field trip and visit.
10. I want to learn some maintenance and common sense of electrical appliances. Where can I find information?
Xinhua Bookstore has all kinds of maintenance materials, e-newsletter, home appliance repair and home appliances, which are not bad.