Smartphone Xiaomi Mi A3 It has become one of the most popular devices in its price segment thanks to a clean Android One operating system and high-quality mobile devices. AMOLED-But like all electronics, this machine is not immune to mechanical damage, to screen breakage, to battery failure. It often requires the wearer to disassemble the device completely to gain access to the internal components to perform a quality repair. This process requires accuracy, special tools and understanding the sequence of actions, since the design of the phone has its own characteristics.
Unlike many modern models, where the rear cover is glued around the perimeter, the Mi A3 uses a removable rear panel scheme, which greatly simplifies the initial stage of disassembly. However, inside the case there are many small plumes, screws of various calibers and fragile connectors that can easily be damaged if you carelessly handle. In this guide, we will discuss how to properly open the case, disconnect all modules and do not damage important components.
Before work begins, the workplace must be well lit and the surface clean and flat so as not to lose small screws. It is recommended to use an antistatic mat or at least a blank sheet of paper. It is also critical to turn the device off completely before disassembling. If the screen is broken and does not respond to touch, press the power button for 10-15 seconds to force the shutdown. Never try to disassemble the phone while it is on, as this can lead to a short circuit on the motherboard.
Tools and workplace preparation required
For high-quality and safe disassembly Xiaomi Mi A3 standard set of screwdrivers will not be enough. You need a specialized tool that will allow you to act on the fasteners without the risk of tearing threads or damage plastic latches. The main tool is a set of precision screwdrivers, including cross bits sizes PH00 and PH000. This is the size of the screws in the lower part of the body and on the clamps.
You'll also need plastic pickers or blades to open the case. Metal tools are not recommended because they can easily damage the frame or, worse, break the battery. To work with small parts and screws, you need tweezers with curved ends. If you plan to replace a display or battery, you'll need a hairdryer or thermophen to soften the adhesive, although the Mi A3 doesn't use as much of it as in all-glass monoblocks.
- 🛠️ A set of precision screwdrivers (mandatory availability) PH00 and PH000).
- 🔧 Plastic blades, mediators or suction cup for neat opening.
- 📏 Tweezers with thin and curved ends for extracting small details.
- 🌡️ A hair dryer or thermophene to soften the adhesive layer (when replacing the screen).
Pay special attention to the organization of space. The screws in a smartphone are used in different ways: long, short, with a wide and narrow hat. The tangled screws can cause a long screw to go through the board and close contacts, which is fatal for the motherboard. It is recommended to use a magnetic mat with markings or simply to spread the screws in the order of twisting them on a piece of paper, signing the steps.
☑️ Preparation for the dismantling of Xiaomi Mi A3
Removal of the back cover and primary access
We're starting the process of opening up. Unlike many flagships, the back cover of the Xiaomi Mi is a little bit more than a few. A3 It's made of glass, but it's not just attached to glue, it's also attached to screws. SIM-To do this, use a special paper clip that comes with the kit, or a thin needle. Press the tray hole at the bottom of the left side and remove it. This is a mandatory procedure, because trying to remove the lid with the tray installed will cause it to break.
Once you remove the tray, turn the phone down. At the bottom of the case, next to the USB Type-C connector, you'll see two screws. They're symmetrically positioned on either side of the charging port. Use a PH00 bat screwdriver to unscrew them. Carefully: If the screw doesn't lend itself, don't use excessive force, try to push down a little bit and turn smoothly. A broken screw hat will create serious problems in further assembly.
When the screws are twisted, you can start removing the back cover itself. It's held on a double-sided tape around the perimeter. Carefully insert a plastic blade or mediator into the joint between the frame and the glass, starting at the bottom corner. Don't go too deep into the tool so as not to damage the plumes that can run close to the edges. Slip along the side faces, gradually peeling off the lid. Don't blow the lid in the center, there's a fingerprint scanner that can be damaged by bending the glass.
⚠️ Attention: Rear window Mi A3 When unsticking, try not to create strong pressure points. If the lid is too tight, warm the perimeter of the body slightly with a hairdryer at low temperature (no more than a few times). 60-70 degrees 30-40 seconds.
Once the lid has moved around the perimeter, don't pull it upwards, and inside the top is a fingerprint scanner plume that connects the lid to the motherboard, and if you move it around, it will break the plume, and the scanner will stop working. Carefully lift the bottom of the lid, find the scanner connector, and disconnect it with a plastic blade.
What to do if the back window is broken?
Dismantling the protective plastic panel and disconnecting the battery
When you take the back glass panel off, you'll see the inside of the smartphone, and most of the space is covered by a black plastic lining that acts as a radiator and protection for the components, which closes access to the battery, motherboard and main camera module, and it's attached to a lot of screws of different sizes, located around the perimeter and in the center.
To remove the plastic panel, you'll need a PH00 screwdriver again. Take a close look at the surface: screws can be hidden under stickers or have different lengths. Unscrew all the visible screws. Notice the screws at the bottom, near the vibrator motor and speaker, which are often different in length from the screws at the top. After unscrewing all the fasteners, gently tuck the panel with a plastic blade and remove it.
Now that the insides are open, the first thing you need to do is turn off the battery. It's the golden rule of any electronics repair. Find the battery connector, which is usually located at the bottom or center of the board, and disconnect it by gently tweaking it with a plastic tool. Only after the device is de-energized can you safely turn off the other plumes: the display, the cameras, the buttons, and the charging port.
- 🔋 Turn off the battery connector first to avoid short circuits.
- 📱 Disconnect the main display plume and the lower board plume (charging).
- 📷 Carefully remove the main and front camera plumes if they interfere with access.
- 🔊 Do not forget to turn off the plume of the lower speaker and vibromotor before the complete removal of the board.
Plastic panels often have protrusions that go under other cells, so take it off without jerking, and underneath it you'll see a metal screen that covers the processor and memory, and the battery itself, which occupies most of the volume. If your goal was to replace the battery, now is the right time to do so, because it's fully accessible.
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Disabling the battery is a critical step, and while the battery is connected, any negligence with a metal tool could cause the power controller or the entire motherboard to burn.
Extraction of the motherboard and basic modules
For deep disassembly, like replacing the charging connector or repairing the motherboard, you need to remove the board itself. It's mounted at the top of the case. Before extracting, make sure that all the plumes going to the board are turned off. This includes camera plumes, display, volume and on buttons, and antenna contacts.
The antenna contacts (springs) are often located around the perimeter of the board and are pressed against the contact areas on the lower board or frame. When removing the board, they can catch on, so act slowly. The Xiaomi Mi A3 motherboard is compact enough and sits tightly in its bed. Carefully tuck its edge with a plastic blade and lift. If the board is not going, check if you forgot to unscrew any screw or snap the lock.
Under the motherboard, there's often a plume connecting the mainboard to the bottom board, where the charging connector is located. This plume can run under the board or sideways. Be very careful: the plumes in the Mi A3 are thin and easily torn. If the plume is under the board, first gently raise the fee, release the plume from under it, and only then remove the board completely.
| Component | Location. | Feature of attachment | Risk of withdrawal |
|---|---|---|---|
| Maternity fee | Upper body | Screws + locks | Under-payment plume break |
| Battery | Central part | Glue base + connector | Puncture of the battery body |
| Main camera. | Centre-top (under plastic) | Tight landing in the groove | Damage to the lens or plume |
| Lower fees | Lower part of the hull | Screws + plume | Microphone damage |
Once you remove the motherboard, you get full access to the bottom of the smartphone, and there's a vibrator, speaker and charging connector. To replace the charging connector, you usually just need to remove the bottom board completely, unscrewing 2-3 screws and disconnecting the main plume. This is one of the most frequent repair procedures, because the Type-C connector is subject to active mechanical wear.
Replacement of the display and work with adhesive joints
If the cause of the disassembly was a broken screen, the process is complicated by the fact that in Xiaomi Mi A3 used AMOLED-It requires heating to replace the framed display (which is simpler) or the matrix separately (which is more complex.
Use a hair dryer to warm up the edges of the screen. The temperature should not exceed 80 degrees, so as not to damage other components if they are still in the body, or to deform the plastic frame. After warming up, use a thin string or a special fishing line to cut the adhesive layer. Strip the perimeter, making sawing movements. Metal blades here are dangerous to use, you can crush the new matrix.
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When installing a new screen, be sure to use a new adhesive layer (B-7000 or special adhesive tapes). The old glue has lost its properties, and without it, the screen will luft, and dust and moisture will get inside the case.
After removing the old display, carefully clean the frame of the glue residue. The new matrix should be installed on a flat surface. Before final assembly and gluing, be sure to test the connection. Connect the new screen plume to the board, connect the battery and turn on the phone. Check the touchscreen, the presence of broken pixels and the approach sensor.
If the test is successful, apply a thin layer of B-7000 glue to the frame or use a special duct tape. Press the screen and lock it with gums for 15-20 minutes before the initial glue grasp. Don't turn the phone on immediately after assembly, let the glue dry for at least an hour.
Assembly of the device and verification of functionality
The Xiaomi Mi A3 is assembled in reverse disassembly. This seems obvious, but requires care. Set the motherboard in place, making sure all screw holes match and the plumes are not pinched. Connect the main plume (screen-board-charging) and the battery. Only after the battery is connected can you check the health.
Turn on the device and check the basic functions: sensor, cameras, speakers, microphone and vibration. If everything works correctly, you can proceed to the final fixation. Twisting all the screws, starting with the ones that hold the board, then install a plastic protective panel. Make sure that it sat flat, without gaps and creaks.
The back cover before installation is preferably dust-free and degreased. If you use a B-7000 glue, apply it in a thin layer and let it lie down for 2-3 minutes to make it sticky. Press the lid and lock tightly. Screw the screws at the bottom last. Wipe the case from the fingerprints after assembly.
⚠️ Attention: If the phone doesn't turn on after assembly, don't panic. Check if the battery and display connectors are tight. Often the problem is a not-completely-clicked plume. Also make sure the screws aren't tangled up and don't create a circuit.
Properly executed assembly ensures not only the appearance, but also the preservation of moisture protection (as much as possible after opening) and the normal operation of the radio modules. antenna contacts must fit tightly to their sites, otherwise there may be problems with receiving the signal Wi-Fi or cellular network.