Microwave furnaces typically consist of protective devices, microwave transmitters, rotors, barbecuers, control devices, etc. Although there are many manufacturers of microwave stoves, there are no significant differences in the composition of the circuits due to the basic similarity of the working principles and composition of microwave stoves, as shown in the figure below。
As can be seen from the figure, each part of the microwave makes up has its own characteristics and working methods and, when it fails, its own characteristics. Thus, an in-depth study of the basic structure and working principles of the microwave is the basis for the maintenance of the microwave, while an understanding of the malfunction characteristics of the microwave and the overhaul process is an important method of overhauling the microwave。
The associated metaware resulting from the frequent malfunctions in the microwave oven are shown in the table below. During the physical overhaul of the microwaves, the features of the malfunctions were combined with the relevant metaware listed in the table。
I. Electrifying non-working
Unfunctional malfunctioning of the microwaves means that the operating display panel is not visible after the microwaves are powered and the buttons in the control device fail to bring the microwaves into working condition. Such failures involve protective and control devices。
In the event of electrical failure in the microwave oven, tests shall be carried out according to the following overhaul process:
1. Test protective devices
The protective devices consist mainly of molten units, thermostats, door switches, and monitoring connection switches, and should be replaced in a timely manner if damage to the above-mentioned metaware is detected。
2. Test control devices
Microwave furnaces are still not operational under normal protective conditions, and in most cases the controls fail. Since the microwave controls are mechanical and computer-based, analysis should be based on actual failure。
A mechanical control device will only be required to detect the timer and its frame, while a computer control device will be required to detect the element, microprocessor, that controls the circuit。
Ii. Non-heat
Unheated malfunctions in microwave furnaces, usually caused by microwave transmitters, should be detected in the event of unheated malfunctions according to the following overhaul process:
1. Detection of magnetic tubes
Magnetic tubes are important elements of microwave transmitters and, if they are damaged, the microwave is unable to heat them, so the magnetic tubes are replaced。
2. Detection of high voltage caps and high pressure diodes
High-voltage capacitor and high-pressure diode tubes are important elements associated with the magnetic tube, which, if damaged, can also be dysfunctional。
3. Detection of high pressure transformers
If the high voltage caps and the high pressure diodes are normal, the failure point may appear on the high pressure transformer, so that the high pressure transformer should be tested and the malfunctioning high pressure transformer replaced。
Iii. Uneven heating
The use of microwaves to cook food often results in uneven heat failures. This failure is usually caused by the deterioration of the functions of the microwave transmitter due to the ageing of the magnetic tube and the failure of the rotor。
Iv. No barbeque or barbeque irregularities
Microwaves with barbecue functions allow the food to be roasted for cooking, using quartz tubes, and thus often fail to barbeque or barbeque. The primary metaware to control the functions of the barbecue are the barbecue unit and the switchboard unit, which should therefore be primarily tested。
V. Vibration
When cooking food from microwaves, there is a high degree of noise, accompanied by a visible vibration. This is due mainly to the fact that the food trays in the rotor drive were not evenly placed or the voltage motor, the high voltage transformer was relaxed。
