Xiaomi Mi A3: how to remove the back cover – Step-by-step

Disassembly of the Xiaomi Mi A3 smartphone is often necessary when the device is mechanically damaged or requires replacing a failed battery. Self-performance of this procedure saves significant money on the services of service centers, but requires extreme accuracy and understanding of the design of the gadget. The back panel here is made of glass, which makes it fragile and requires special approach during dismantling.

Before you start physically affecting the body, you need to make sure that you have a specialized tool and prepare the workplace. The adhesive base that locks the glass to the frame only melts when you reach a certain temperature, so without preheating, there is a risk of splitting the lid or damaging the frame. In this article, we will discuss each step of the process in detail.

It is important to understand that opening the case automatically deprives the owner of the right to warranty service at official points. If your smartphone is still under warranty and the problem is not related to physical damage, it is better to contact authorized specialists.

Tools and workplace preparation required

The quality of the repair depends on the toolkit used. To work with the Xiaomi Mi A3, you will need not only a standard set of screwdrivers, but also specific devices for working with adhesive joints. Lack of the right tool often leads to damage that can not be repaired without replacing entire nodes.

First of all, take care of the heat. A normal household hair dryer may not give you enough temperature, so professionals use a thermophen or special heating platforms. If you use a hair dryer, keep it 2-3 cm from the surface and constantly move it so that one point does not overheat.

You'll need thin metal blades or special suction cups to peel off the glass. Plastic mediators are good for the initial stage, but cutting through hard glue often requires a thin blade. Be careful: metal can scratch the frame or damage the internal plumes if you go too deep.

• 🔧 Thin cross screwdriver (usually) PH00 or PH000) motherboard screw.
• 🔥 A dryer for heating the glue or a heating platform (temperature about 80-90 degree).
• ✂️ Thin metal spatula or scalpel for primary opening.
• 📏 Plastic mediators or cards for safe disconnection of glass.
• 🧴 Clay. B-7000 or E-8000 reverse-assembly.

⚠️ Note: Before starting the work, be sure to remove SIM-card and microSD tray. Attempting to remove the lid with the tray installed can lead to its breakage or damage to the internal contacts of the connector.

Organize the space so that all screws and small parts are under control. Magnetic mat or container with cells will help you not lose microscopic screws, which are easily lost on the table. Also make sure that the workplace is well lit, as some of the connectors inside the smartphone are very small.

Heating process and primary opening of the body

The most critical step is heating the perimeter of the rear cover.The glue used in the Xiaomi Mi A3 only becomes elastic at around 80 degrees Celsius.Insufficient heating will cause the glass to crack under the pressure of the shoulder blade, and excessive can damage the display or battery.

Warm up the ends of the smartphone evenly for 3-5 minutes. Pay special attention to the corners and the bottom, where the glue often freezes thicker. Periodically check the temperature with your finger: if the hand is hot but tolerant, then the temperature is close to optimal.

Once warmed up, take a suction cup and attach it to the bottom of the back cover. Pull the suction cup up slightly, creating a small gap between the glass and the frame. Insert a thin metal blade or blade gently into this gap.

Move the blade along the perimeter, cutting the adhesive layer. Don't try to tamper with the glass all at once; it's better to move in small areas, periodically warming up the cooling places. The plume of the fingerprint scanner is at the bottom, so there you need to be especially careful with the depth of the tool.

Disabling the plumes and removing the cover

When the adhesive layer around the perimeter is cut, don't be in a hurry to remove the back panel completely, and inside it's connected to the motherboard by a fingerprint sensor plume, and a sudden movement can break this thin conductor, and then the scanner will stop working.

Carefully lift the glass and pull it aside like a page of a book, you'll have access to the insides, and the first thing you need to do is turn off the battery to shut down the system and avoid short circuits when working with other components.

Use a plastic blade to snap the battery connector, and then you can safely disconnect the scanner plume, which is located at the bottom of the case and is fixed in the motherboard connector.

• 🔋 Disconnect the battery connector first to secure the electronics.
• 👆 Carefully tuck the fingerprint scanner plume and remove it from the connector.
• 🧩 Check the integrity of the plumes: they should not be broken or broken.
• 🧹 Remove the remnants of old glue from the frame before installing the new cover.

Now that all the joints are broken, you can take the back cover completely off, put it on a soft cloth so you don't scratch the glossy surface, and check the frame for any glue residue, and you need to remove it carefully, because it will interfere with the tight fit of the new panel.

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Use isopropyl alcohol and a lilac-free napkin to clean the frame of the old glue, which will provide the perfect adhesion of the new adhesive layer.

Replacement of battery and other components

When the lid is removed, you can access the main nodes of the smartphone, and most often, the Xiaomi Mi A3 is disassembled to replace the battery, which eventually loses capacity, and the battery is glued to the case, so it also requires heat and accuracy to extract it.

To replace other components, such as the vibrator motor or the lower charging plume, it may be necessary to remove the plastic protective cover covering the main part of the motherboard.

When working with a battery, never use sharp metal objects to tamper with the battery. Puncture of a lithium polymer cell can cause fire. Use plastic cards and a dryer to soften the glue under the battery.

If you are changing the battery, make sure the new cell has the same characteristics as the original.The smartphone power controller may not work properly with substandard copies, leading to quick discharge or charging errors.

Assembly of the device and lid gluing

The assembly is done in reverse order, but with important nuances. Before installing the cover, you need to apply a new layer of glue. For the Xiaomi Mi A3, rubber-based adhesives such as the B-7000 or E-8000, which retain elasticity after drying, are best suited.

Apply a thin strip of glue around the perimeter of the frame, avoiding getting into the camera and speaker. Let the glue dry a little (about 1-2 minutes) so that it is no longer liquid but sticky. This will prevent the excess from being squeezed out when pressed.

Connect the fingerprint scanner plume and put it neatly in the designated area. Then connect the battery. Make sure all the plumes are flat and nothing is squeezed. Only after checking all the connections, put the back cover on.

Press the edges of the body hard around the perimeter. To evenly distribute the pressure, you can use rubber rings or put your smartphone under the press (heavy book) for 1-2 hours, this will ensure reliable fixation and tightness.

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The quality of the lid gluing depends not so much on the amount of glue, as on the thorough cleaning of the old surface and uniform pressing during drying.

Frequent errors and precautions

Beginners often make mistakes that lead to additional costs. One of the most common is trying to remove the lid without enough heat. The Xiaomi Mi A3 glass is quite thin and bursts at the slightest skew of effort.

Another mistake is that the scanner plume is damaged, and if it's not opened properly, it's easy to break or damage the contacts, and remember that this plume is often assembled with a lower board or requires soldering, which makes repairs more difficult.

Don't ignore the screws of different lengths. In some models, the screws of the board mounting may differ in length. If you screw a long screw into a short hole, you can damage the motherboard through.

• ❌ Do not use superglue (cyanacrylate) – it hardens and makes re-examination impossible without damage.
• ❌ Do not heat the battery directly – it can cause it to swell or ignite.
• ❌ Don’t forget to check all functions before the glue is finally dry.

⚠️ Warning: If the phone doesn't turn on after assembly, don't panic. Check if the battery connector is fully inserted. Often the problem lies in poor battery contact.

It's also important to check the waterproofing, because once you open it, you lose the sealing in the factory, and you don't have to count on the smartphone to withstand the water after you've repaired it.

Questions and Answers (FAQ)