The Xiaomi Mi 3, released back in 2013, has become a true bestseller of its time, laying the foundations of the company’s modern philosophy. Despite its age, many enthusiasts still use this device or try to breathe a second life into it for nostalgia or educational purposes. However, time does not spare lithium-polymer batteries, and over time, the question of how to disassemble the Xiaomi Mi 3 to replace a worn-out battery becomes critical for the owner.
The process of dismantling this device has its own unique features, which distinguish it from the more modern models of the brand. There are no usual screws at the charging connector, and the body itself is assembled using a powerful adhesive layer, which requires special care and the presence of specific tools. Wrong actions can lead to damage to the plumes or, worse, to a puncture of the battery, so studying the theoretical basis before starting work is absolutely necessary.
In this article, we will take a detailed look at each stage of disassembly, from removing the back cover to turning off the motherboard. You will learn about the nuances of working with the adhesive base, the correct order of screws unscrewing and methods of safely removing components. Following the instructions will help you avoid typical mistakes and successfully complete the repair of your smartphone with your own hands.
Tools and workplace preparation required
Before you start to physically affect the body of the device, you need to prepare the workplace and the appropriate tools. dismantling Xiaomi Mi 3 does not tolerate the fuss, as the components are dense enough, and the fasteners are of different size and length. To successfully perform the operation, you will need a set of precision screwdrivers, including cross (PH000, PH00) and possibly flat for working with latches.
Special attention should be paid to tools for working with glue. Since the back cover is glued around the perimeter, you will need a construction hair dryer or a special heater (separator) to soften the adhesive. A regular household hair dryer may not give enough temperature, which will break the plastic when you try to open. Also prepare thin plastic blades, mediators and a sucker for careful snapping of the case.
- 🛠️ Precision screwdriver kit (cross-hatch) P2, P5) screw-twisting.
- 🔥 Building hair dryer or heating pad for uniform heating of the adhesive layer along the perimeter.
- 🧩 Plastic blades, mediators and metal scalpel (with caution) to open the body.
- 🧲 Magnetic mat or organizer for sorting screws, so as not to confuse them when assembling.
⚠️ Note: Metal tools such as a scalpel or tweezers are used only for working with the outer perimeter. Internal manipulations are carried out exclusively with plastic, so as not to damage the plumes and cause a short circuit in the chain.
The organization of space is key to the success of the operation. Make sure you have good lighting and sufficient table area. It is recommended to use a magnetic mat or a piece of paper with a drawn circuit, where you will lay the screws in the order in which they were removed, which will save you a lot of time and nerves when you reassemble the device.
☑️ Preparation for the dismantling of Xiaomi Mi 3
Primary dismantling: Removal of the back cover and battery
Unlike many modern smartphones, where the battery is under the display, the Xiaomi Mi 3 has it under the back cover, which makes it somewhat easier to access the main power source. Start by turning off the device and removing the tray SIM-Then warm up the perimeter of the back with a hairdryer, paying special attention to the corners and areas around the camera lens.
Once the body warms to about 60-70 degrees (plastic should get warm but not melt), try inserting a suction cup at the bottom of the lid. Create a vacuum and pull up slightly, forming a small gap. Insert a thin plastic blade or mediator immediately into this gap. Don't try to tamper with the nail lid - you risk breaking or damaging the plastic of the case.
Move the shoulder blade along the perimeter, gradually cutting through the adhesive layer. Act slowly, feeling resistance. If the lid does not respond, stop pulling and warm up the problem area again. Sharp movements can lead to cracks in the back panel, which in older models may already lose its elasticity.
What to do if the lid is cracked?
When the lid is removed, you'll see the battery covered with a logo sticker, and there's a special tongue on the bottom edge of the battery to remove the battery, pull it to unstick the battery, and if the battery is sitting tight, you can lightly tamper with a plastic card, but avoid pressing the center of the battery.
Disassembly of the main part: screws and protective plates
Once the battery is removed, you will have access to the main board and internal components. At this stage, it is important to exercise maximum care, since screws that attach protective metal plates can have different lengths and threads. The Xiaomi Mi 3 uses many small screws that cover the display plumes, cameras and charging connectors.
Start by unscrewing all the visible screws on the black security covers. Notice the screws around the main camera lens and at the bottom where the speaker is located. Some screws may be hidden under stickers or warranty seals that will have to be carefully removed or punctured. Keep the screws in order, as screwing a long screw into a short hole can punch through the board.
| Disassembly zone | Type of screw | Number of | Features |
|---|---|---|---|
| Perimeter of the shell | Cross PH00 | 12-14 pcs. | Same length, hold the frame. |
| Battery protection | Cross PH000 | 2 pcs. | Short, easy to lose. |
| Fee (main) | Cross PH000 | 4-6 pcs. | Different lengths, important sorting |
| Lower fees | Cross PH00 | 2 pcs. | Lock the charging connector. |
You take off the metal plates, you get access to the connectors. The plumes in the Xiaomi Mi 3 are connected quite tightly. Use a plastic blade or nail to turn them off, putting the connector upwards. Don't pull the plume itself, you'll tear thin current tracks. First, turn off the display plume, then turn off the touchscreen, cameras and, batteries, if it's not finally removed.
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Before turning off the plumes, take a close-up picture of the location of all the connectors, which will help you not confuse them when you build them, since some connectors are visually very similar.
Extraction of motherboard and modules
The Xiaomi Mi 3 motherboard is fastened tightly enough and surrounded by plastic bezels. Once all the plumes are turned off and the screws are unscrewed, the board can be retrieved. This should be done carefully, holding the area around the processor with your finger so as not to create excessive pressure on the chipset. Often the board can stick to the case due to old glue or heat pads.
Note the main camera module. In this model, it's quite large and can interfere with the removal of the board if you don't remove it first. The camera is based on adhesive and a press plate. Carefully tuck the camera module, trying not to touch the lens with your fingers, because fat spots are difficult to remove, and it's also worth checking the status of the microphone and polyphonic speaker, which are often clogged with dust.
At the bottom of the device is a child board with a charging socket, and it's connected to the main board with a flexible plume that runs along the body. When you remove the main board, make sure that this plume is free and not stretched. If you plan to completely disassemble to the "naked" case, you will need to remove the lower board by unscrewing the screws in the area of the dynamic head.
⚠️ Attention: When removing the board, watch for antenna contacts (springed pens) that are very fragile and easily lost. If such contact is lost, immediately find it and put it away to a safe place, otherwise after assembly, the network signal will disappear.
Nuances of working with the display and touch screen
Replacing the display with the Xiaomi Mi 3 is one of the most difficult operations, because the matrix and the glass (touchscreen) are separated here, but assembled into a single module with a frame. If you only have broken glass, replacing the entire module will be the easiest, but expensive solution. If you change only glass, you will need to use a separator and a UV curing lamp, which is extremely difficult to do at home.
To remove the display module, you need to completely free the body of all internal components. The screen is glued to a metal frame around the perimeter. Use a hair dryer to heat the front panel. Be extremely careful: the glass becomes even more fragile when heated. Push the module with thin blades on four sides, evenly increasing the gap.
It's important to note that the touchscreen plume and the matrix plume (LCD) are different in direction and have different connector designs. The matrix plume is often further fixed with a metal bracket. When you install a new screen, be sure to check the touchscreen's performance before the final sticking, and you can temporarily plug the plumes in, turn on the phone, and check the response to touch.
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Replacing the display in the Xiaomi Mi 3 requires a complete disassembly of the body. Always check the new screen for health before applying the glue to avoid re-disassembly in the event of a marriage.
Assembly of the device and verification of functionality
The Xiaomi Mi 3 is assembled in reverse disassembly, but there is a critical point: before the final twist of all the screws and the back cover is sealed, you need to conduct an initial test of the device. Connect the battery, the display plume and the touch screen, then try to turn the smartphone on with the power button.
If the phone is on, check the sensor, the speaker, the microphone, the ringing and the vibration. Make sure that Wi-Fi and Bluetooth are stable, this will check the status of the antenna contacts. Only after you have successfully passed all the tests, you can start the final fixation of the components. Apply a thin layer of glue B-7000 or a special adhesive around the perimeter of the back cover.
When twisting the screws, don't put too much effort into it. The plastic of the old smartphone's body could become more brittle (fragile) from time to time. Twisting the screws cross-cross, gradually tightening them to ensure that the cover fits evenly. Let the glue dry for 2-4 hours before active use of the device.