I. Common overhaul tools and instruments, instruments
(i) universal tools
Common tools required for household electrical maintenance are shown in table 1. Where conditions permit, a set of combination tools may be available, as shown in figure 1。
The common tool for the overhaul of household appliances includes insulation tape, ab tape, etc。
(ii) specialized tools
In addition to the use of general tools such as screwdrivers and pliers, the overhaul of computer panels requires tools such as iron branding, as shown in table 2。
(iii) instruments, instruments
The overhaul of domestic appliances also requires the use of meters, oscillators and instruments, as shown in table 3。
Ii. Common methods and care for repairing household appliances
This section presents the usual methods of overhaul and care used in the repair of household appliances, which are based on reasonable and skilled knowledge of these methods of overhaul and on rapid and safe troubleshooting。
I. Interrogation and inspection methods
Inquiries are the most basic method of repairing household appliances. In fact, the method is also most easily ignored by beginners and primary maintenance staff, who, without patient inquiries from users when they are confronted with a malfunction, begin to disassembly, sometimes not only without rapid failure, but also with discomfort and even litigation. It is therefore important to carefully ask about the malfunctioning characteristics of the user malfunctioner and the cause of the failure before it is maintained, which is half-wired for many repairs. For example, if the user is asked to learn that the remote control has been broken, the main check is whether the circuit board has elements to weld or, if not, the crystallization. For example, when the refrigerator compressor is not functioning, when the cooling effects of the refrigerator are poor, the failure is caused by a leak in the refrigeration system or by the compressor anomaly; when the temperature is too low (e. G. Cold room freezes), the failure is caused by the contact point of the thermostat that cannot be broken. For example, in the case of the maintenance of dry drums of double-barrel washing machines, it is asked whether there is a leak in the drums, which, if so, indicates that the spill caused the dryer to burn down; if not, the main check is for running caps and safety switches。
(ii) visual inspection
Intuitive inspection is the most basic method of repairing household appliances, through which preliminary diagnosis of the fault areas can be made. The review was conducted by means of hearing, looking, touching and hearing。
Listen
Listening is the method of repairing the parts of the malfunction and the causes of the failure that are detected through the ears. For example, when repairing small household electricity, such as paint, microwave, electromagnetic furnaces, disinfectant cabinets and so on, when listening to “clap” discharges, check whether its high voltage device is being discharged to the ground. For example, when checking electric fans and gas smokers, if mechanical noise is excessive, check if the electrics are not rotated. For example, the hearing compressor does not function when the refrigerator is not refrigerated; if the compressor is functioning, the compressor, the starter and its electrical circuits are inspected; if the compressor is operating, the sound of a refrigerant flow within the evaporation unit cannot be heard, indicating a leak or plug in the refrigeration system。
Look
It's a way to detect the faults and cause by observation. For example, when inspecting domestic appliances for failure to function, the negative content is judged first by checking whether the smelter has melted; for example, when overhauling the low voltage power source of the air conditioner is not working, it is judged whether it is damaged by checking whether the transformer of the low voltage power is deformed or coloured; and for example, when overhauling the washing machine is not functioning, it is judged by examining whether the electric machine, the appearance of the electrical surface, has changed colour. In addition, when overhauling circuit boards, they are judged to be normal by examining the convulsive, transistor, integrated circuits, etc. For the majority of exposures to faults, the faults can be found by checking whether the triggers of the links and components are in poor contact and whether circuit boards are broken。
Three. Touch
Touching is the method of repairing the point of fault and the cause of the failure by hand, for example, by measuring the temperature on the surface of the device, such as the ticulator, heater, and, if the temperature is normal, indicating that it is working; if there is no temperature, indicating that there is no work; if there is heat, indicating abnormality in the electrical circuit. For example, when the washing machine is not functioning properly, the presence of miscellaneous items under the wheel can be determined by dialing the wheel to see if it can rotate normally. For example, when repairing circuits on circuit boards, it is possible to determine whether the triggers are welded or in poor contact by touching a component and the strength of the connector。
[note] since many small household power lines are connected to the municipal power supply lines, such access is a “hot” approach, it is applied in a safe manner, without electrical accidents and in a way that does not cause burns when touching objects such as heaters。
4. Smell
The smell is the method of repairing the part of the fault and the cause of the failure by sniffing through the nose, for example, when the machine of the washing machine does not turn off, if there is an abnormal smell that indicates damage to the power plant or its operating face. For example, treatment of uv-type sterilised small household electricity means that the disinfection circuit is not working if it does not smell the uv-sterilized odour. Similarly, when overhauling the ozone-type disinfectant cabinet, failure to smell its ozone odour indicates that it is not working。
Iii. Employment
Pressure measurement is one of the most common methods of overhaul. The method used to determine the location and cause of the failure by measuring the normality of the exchange voltage or current voltage at the suspected point. For example, in the case of small power failure, such as the repair of electric canteens and irons, it is possible to determine whether there is a 220v municipal voltage in the municipal electric outlets, whether the municipal electricity system is abnormal or the small household electricity malfunction。
(iv) barrier measurement
Role
Interdiction measurement is one of the most important methods of remediation. This is the method by which the fault area and cause of the failure are judged by the normality of the suspected circuits, the resistance of the device. For example, when repairing a fan, a smelting device for a washing machine breaks down a failure, it is possible to determine whether the electric power, the capacitor, is normal and to determine whether the malfunction is caused by their abnormality or otherwise. Also, for example, when the cooking pan, the frying pan, without heat failure, is checked to determine whether it is moving. On the other hand, when circuit board failure is repaired, it can be verified by measuring the resistance value of the object, such as resistance, sensory, etc。
[note] when measuring components using resistance measurement methods, the `walks ' must be carried out in case of power cuts, otherwise they are prone to damage to the universal-use watch。
[methods and techniques] can be measured in the event of a breakout of a device such as a circuit, a breaker, etc., using a one-size-fits-all meter breaker (some of the numbers are attached to the "biode" block) and if a one-size-fits-all beeper makes a sound indicating that the line is normal; if there is no call, the line is broken; if there is no call, the line is not in good contact。
Classification
There are two types of resistance measurements on and off the road. Road detection is the method of directly detecting the resistance value of the component on an online road or on a circuit board, rather than on the road itself。
[methods and techniques] are usually used for road surveys in the rx1 or 200 and “interruptive measurements” series。
[note] adopt small resistance devices that are detectable during road-detection of resistors and cannot be linked to the device, which would otherwise lead to greater data error detection。
Temperature method
Temperature methods are a method of determining the cause of failure and the location of the failure by touching the surface of a component and the temperature of the component. With some maintenance experience, this method is better used in determining whether the power tubes of the electromagnetic furnaces and the flow stacks are normal. After short-term electrical access, if they are over-temperatured, they are indicative of high-capacity or overflow. In addition, the method is more useful in determining the normality of the heat-sensitive electrical resistance, which, after heating the heat-sensitive electrical resistance of the negative temperature system, indicates damage if the resistance is significantly reduced。
(c) [note] be safe when applying temperature methods in order to avoid electrical or burns。
(vi) substitution
Substitution is the method by which the normal elements of the same specification are replaced by elements that are not easily judged. In the maintenance of small household circuits, the normality of the capacitor, the voltage tube, the integrated circuit, sensory devices (voltage transformers, wires, etc.) is determined mainly by the substitution method, which can also be used to determine the performance of poor triodes. Maintenance can, of course, also be conducted using a whole-shifting method for the determination of faulty areas, for example, when it is suspected that an abnormal operating panel causes a computer-controlled small power operation, it can also be replaced by a normal operating panel as a whole, which, if restored, would indicate an unusual operating panel that was replaced。
Vii. Methodology
The way to open a road is to judge the fault area by removing a device. For example, when the power output of the power for the maintenance of the colour power is low-intensity, the output voltage reverts to normal, mostly burden abnormality, when the load is broken; if the voltage is still low, it means that the electrical circuits are too high, thus creating a failure of low carrying capacity。
[note] some load abnormalities cause power-type elements of power to increase the temperature of the power source when the power-out voltage is low, and, if not, the power-out voltage is restored to normal or near normal after the disconnection load, mostly by internal resistance within the power source, causing power-load capacity differentials. Care should be taken to distinguish between maintenance and not miscalculation。
(viii) purge method
The working environment of some household appliances (e. G. Kitchens, bathrooms, small household appliances) has caused them to become water-prone or contaminated by oil and smoke, causing malfunctions in the operation of circuit boards, main boards due to tides, non-working, occupational disorders or partial control functions, and therefore the cleaning method has also been used to overhaul household appliances, in particular the important method of repairing the failure of kitchens, bathrooms, etc. Cleaning is best done using waterless alcohol or water, and then drying or drying, so that a test machine can be installed。
(ix) short-circuit law
Short circuits are one way to judge the fault area by using a part of the circuit or a piece of device. For example, when a computer-controlled refrigerator compressor does not fail, c, e of the short-link compressor power circuit drive c, if the compressor is able to rotate, indicates that the compressor or its starter is normal and that the failure occurs in the compressor power circuit; and for example, when a review of the remote control key is partially uncontrollable, the failure of the short-stroked two-legged welding points indicates the broken key. Short-circuit methods can also be used to make judgements in case of suspected circuit break-ups。
(x) emergency repairs
The emergency repair method is one way of repairing by cancelling a part of the circuit or a device. For example, when domestic appliances, such as air conditioners and soybean slurry machines, are repaired and found to cause a smelting device to melt because of their pressure-sensitive short circuits, failure to install and replace the smelting device can be eliminated without the element on hand; and, for example, when damage is caused by the compound-type overheating protection for small household appliances, such as drinking water units and electric canteens, replacement may be done with a single smelting overheating protection of the same temperature value。
[telephones] as municipal voltage is not effective at normal times and the current municipal voltage is stable in the country, maintenance can be done by not installing voltage-sensitive resistance. However, for some of the emergency repairs, the replacement of household appliances will be performed in a timely manner, subject to the replacement of components, in order to avoid new malfunctions。
(xi) fault code repair
At present, many computer-controlled home appliances have a fail-safe self-diagnosis function to facilitate production and failure maintenance, and when they fail and are tested by the microprocessor circuits at the cpu, the cpu displays the fail-code through a signal light or display screen, alerts the cause of the failure and the area where the failure occurred, so that the maintenance staff quickly finds the fault area through the fail-code. The acquisition of this method is one of the shortcuts to the rapid maintenance of such household appliances。
