The common malfunctions of the microwave are not activated, unheated, slow heating (i. E. Insufficient fire), unturned wheel, intermittent work, open fire, irreconcilable fire, etc., are described below. Note: whenever a microwave is to be removed for inspection and repair, except for otherwise specified and checked for “no-start” power source voltage of 220 v, which is to be performed in the event that the power plug is removed and the power is cut and the high-voltage capacity is discharged. 1. Non-start failure means that the microwave furnace is plugged into the power source, and when the furnace door is closed, the spin-time knobs are not activated by the furnace, the wheel is not turned and the stove cannot be activated. The failure to activate is one of the most visible failures of the microwave, and it's also associated with the wide area of the electrical circuit, a relatively difficult failure to judge. In order to facilitate a quick understanding and mastery of the methods and techniques of judging and repairing this failure, the authors, using as an example the typical circuits shown in figure 1, carefully summarize the practical experience as a detailed flowchart of failure judgement maintenance as shown in figure 2. You can do this with tuso, and you can do an orderly check, and you can usually find out where the fault is. It's also tactile and thought-provoking for other failures. The main causes of non-start failures are: fuse tube f1 melting, overheated st breaker, power circuit failure and security chain switch s1 ~3 bad or damaged. The f1, st and power circuit failure diagnosis and processing is easier, and i'm going to mention it here, mainly with the security switch failure. Most of the problems with s1, s2 were caused by non-starting problems, and the security chain switch s3 was caused mainly by a failure to burn the fuse pipe f1 (which could not be activated after it was broken). For example, the main chain switch s1 should be connected at the close of the furnace door, and if the s1 opening is damaged, whether the door is open or closed, the microwave cannot be connected to the power source. Usually, s1, s2 and s3 are installed on engineering plastic slabs, where the position has been fixed in manufacturing, and there is usually no shift except for rigid variations or a loose screw of fixed plastic slabs, so it is rare for the non-starting or burn fuses caused by the shift. More often in practice, the switch switch and switch trigger poles (i. E. Two hook-like poles on the stove door, also known as door hooks) are damaged or not working on plastic slabs. When these parts are checked, just tearing down the top of the microwave, you can clearly see how they act with each other, and you can open and close the doors, and you can see their movements, and if they're all normal, then check if the switches are normal. Because s1-s3 is for safety, and because of the frequency with which they move, most manufacturers choose to use more durable, reliable, dedicated micro-switches, which can normally be used for long periods of time, but if the switch itself is of poor quality or in poor working conditions (e. G., excessive touch), the life expectancy is significantly reduced. If the switch is damaged because of its length of use or because of the above, the test may be removed and, if the damage is seriously unrepairable, new items shall be replaced. Note that if a prototype or direct replacement is to be selected, care is to be taken that the outer size is appropriate, which does not correspond to the plastic frame that will not be properly loaded into the machine, which is difficult to replace, or not possible. In addition, sl, s2 and s3 have essentially the same shape, but the switch function is different, so no mistake can be made when selecting or installing. Many switches have electrical symbols on their casings, so it's easy to distinguish; if there's no symbols, they can be measured by a universal scale, it's enough to figure out whether they're open or closed and the corresponding exit end. 2. Such failure without heat means that the food does not heat after the microwave is powered, but the general stove light is lit and the wheel is rotated. Unhot failure is mainly due to the lack of microwave output in the microwave. The burner lights will light, the wheel will turn, indicating that the circuit before the high voltage transformer is working, and if the power control switch s5 is also working, then the failure range is in the high voltage transformer t and so on
