Microwave mica is an important element that protects the magnetron and waveguide from high temperatures. The dielectric material also prevents moisture from entering them. Thanks to the mica layer, the emitted microwaves are evenly distributed throughout the chamber.
During operation, the mica sheet becomes unusable. The first signs that a protective shield burned out in the microwave were sparking and lack of heating.
Mica - what is it
Mica is a natural dielectric material that transmits radio waves. There are three types: sheet, powder and intumescent.
In its natural state, the mineral crumbles. To use it as a dielectric layer, it is necessary to apply it on an elastic base - the thickness is 0.4-0.5 mm. The color of the mineral is gray-white, indefinite.
Why microwave a protective screen
The "heart" of any microwave oven is a magnetron that generates microwave waves. It communicates with the camera through a waveguide - its exit is covered by a special plate, similar to a dense fabric. Located on the right wall. If you press with your finger, the surface is pressed through, behind which there is a rectangular opening of the waveguide.
If your microwave oven sparkles - it’s 80% likely that the mica spacer burned in it. What is this flexible barrier for? Firstly, thanks to it, microwaves emitted by the emitter are reflected. Secondly, high-quality heating of products is provided. The gasket is located in the center, right or bottom.
Why is the waveguide separated from the camera by mica
The condition for normal microwave operation is the cleanliness of the waveguide walls. Otherwise, its effectiveness decreases and oxidation occurs. The main purpose of mica plates is to protect the waveguide from grease and other contaminants.
Important! Keep in mind the lid made of plastic, which covers food plates. If grease or other contaminants get on the protective sheet, an electrical breakdown of the dielectric may occur, due to which it will burn out.
The fat that has fallen on the protective sheet burns under the influence of the emitted rays. The plate is destroyed, gaps are formed in it, through which the radiation directly enters the stove. The result is sparking and crackling. Often, along with the overlay, the magnetron cap burns out, the paint burns. If signs of burnout are visible - the stove sparks and crackles are heard, immediately turn off the power and take measures to eliminate the malfunction.
Attention! Experts assure: neither the peeling paint, nor the charred cap interfere with the operation of the device. But only until the moment when the magnetron’s antenna does not completely burn out.
What you need to know about frequencies
Many noticed that next to the microwave oven, mobile phones and Wi-Fi are not functioning well. The reason is the coincidence of frequencies. Household appliances use only the values assigned to it - among them 2.4 GHz. Water of such frequency actively absorbs water, the screen serves as an insulator of the chamber from the magnetron and the waveguide.
Why aren't there microwaves that don't interfere with computers? The point is the prescription of state bodies - it is they who decide what frequencies to work on.
On a note! A 2.4 GHz microwave oven fries chicken. How does a phone operating at a similar frequency affect if it is constantly brought to your ear? That's why the power of mobile devices is limited.
When to replace mica
During operation, the mica plate, contaminated by fat and deformed by moisture, becomes unusable. It can even be populated by fungi.
The first sign that a wall is burnt between the waveguide and the camera is strong crack when turned on. Inside, intense sparking begins, and near the gasket even electric arcs appear. If you look closely, dark spots are visible on the mica. In the presence of an oval with a diameter of 5-6 mm, the stove begins to "resent".
The pad, absorbing fats and aroma molecules, is filled with them over time. Further, the material breaks through electricity - strong sparking is observed inside the chamber. To remedy the situation, you just need to change the broken protection. How to replace a worn out layer? In specialized stores, sheet mica is sold.
Important! The more thorough and regular maintenance, the longer the protective gasket will last. Be sure to clean the inside of the chamber from food, wash smooth parts with mild detergent solutions, and keep the plate clean.
What to do if microwave sparks in the chamber
If sparks are visible in the microwave, there may be several reasons:
- The bottom of the mica leaf burned out. We are considering this case.
- Enamel is damaged. This can happen due to surface contamination that provokes sparking.
- Metal dishes. If the plates have a metallic finish, sparks will appear.
How to replace mica
If you are convinced that the cause of cod and sparks is a burnt gasket, replace it. It is very simple, you do not even need to call a master. If the plate burns out in the microwave, you can replace it yourself. We will consider the gasket replacement sequence using the LG model as an example:
- Get a new plate. Where to get her? Look for shopping or online.
Important! When buying a microwave protective shield, pay attention to the availability of certificates so that it does not cause harm to health.
- Remove the warmed sheet. It can be mounted in different ways: with self-tapping screws, plastic latches. Depends on the microwave model.
- Wash the damaged sheet from dirt - you will need it as a stencil. Cut a new plate with a sharp clerical knife. The holes can be drilled with a suitable size drill or pierced with an awl.
- Rub the cut sheet with sandpaper to remove any irregularities.
- Dry it.
- Remove grease and dirt where the mica leaf will be located. Thoroughly clean the surface.
- After removing the magnetron, inspect its protective cap. The burnt part will have to be replaced.
- Burned areas need to be cleaned with a sandpaper, the peeling enamel should be painted over with a special dye.
- It's time to put a new protective screen. Mounting the plate is quite easy, usually it is fixed in one of the following ways:
- you need to install the sheet in a special pocket secured with a screw;
- if the plate is held by metal tabs, it must be bent during installation. - Now check the performance. But remember: you can turn on the microwave only if there is a moisture-containing product inside - you can’t turn on the empty one. Put, for example, water in a heat-resistant glass.
Is it possible to warm food without a screen
Owners of microwave ovens are often interested: can I turn them on without a gasket or do I need a replacement? Screen - a prerequisite for the operation of the device. If it fails, the stove must not be turned on!
If you want to take a chance, then without a screen the oven is fully operational. If you be careful, cover the food with a lid, then you can not use the stove for long, until you bought a new plate. The main thing is not to delay the repair so that more expensive parts do not suffer: the cap and the magnetron antenna.
Useful Tips
- When removing the magnetron, follow the safety instructions: disconnect the device from the power supply, short-circuit the capacitor for a while.
- Mica is fragile, so you need to cut it with a very sharp knife - boot, wallpaper, clerical.
- To prevent the accumulation of fat on the walls of the chamber, do not be lazy to clean it, preheating for 10-15 minutes at low power. Then wipe the inside walls with a sponge with a cleanser that breaks down the fat.
- When heating food, try not to use too large utensils. Suppose a roomy plate does not touch the walls of the chamber, but when the tray moves it can move out. As a result, touching the walls, the dishes will thin out and damage the enamel.
The network often comes across articles where they recommend simply turning the mica sheet. But with such a solution, the problem will soon return with additional consequences: the cap and the magnetron antenna will burn through. Then depressurization may occur - the stove will simply stop heating products, and repairs will cost many times more.
Why does the manufacturer use mica, how can it be replaced
The material should have the following properties:
- do not accumulate electricity;
- be non-toxic;
- Do not melt at high temperatures;
- skip steam well.
If you use material that does not meet the above requirements, you may become poisonous with harmful substances or get a short circuit. Mica is used mainly because of its low cost.
You can replace it with other material. Instead, you can use a heat-resistant dielectric - fluoroplastic. It is completely smooth, does not absorb fat and moisture. Food grade plastic is a great alternative to mica plates. It is much more reliable and durable, but also costs more.