Xiaomi Redmi 3, despite its age, remains a popular device due to the successful combination of price and performance. However, time does not spare lithium-ion power supplies, and after several years of active use, owners face the need to replace the battery. The main obstacle to rapid replacement is a monolithic body, which does not involve simple removal of the rear panel, as in more modern models. Disassembly of the device requires accuracy, special tools and understanding of the design of the gadget, so as not to damage the plumes or the case itself.
Unlike many budget smartphones, where the lid is held on plastic latches, a combination of adhesive and screw fasteners is used. Wrong actions can lead to chipped faces, damage to the display or, worst of all, a puncture of the old battery. The integrated design of the Xiaomi Redmi 3 was dictated by the manufacturer’s desire to improve the ergonomics and rigidity of the case, but for repairmen this has created certain difficulties. Before starting to dismantle, you need to prepare the workplace and make sure that all the necessary tools are available.
The purpose of this article is to provide the most detailed and safe algorithm for removing the back cover. We will consider not only the mechanical sequence of steps, but also the technical nuances specific to this model. Careful follow-up to the instructions minimizes risks and will allow you to successfully maintain your smartphone at home.
⚠️ Warning: Before starting any work, be sure to turn off the smartphone. Working with the device on with the trains disconnected can lead to a short circuit and the motherboard fails.
To successfully perform the procedure, you will need a specific set of tools that you will not always find in a standard home medicine cabinet. Lack of the right equipment often causes damage to the case or failure of the screw thread. Below is a list of what you need to prepare in advance to ensure that the process goes smoothly.
- 🛠️ Screwdriver kit: a Phillips sized cross screwdriver #00 or #000 is required, as the screws in Xiaomi are very small.
- 🔥 Hair dryer or thermal package: to heat the adhesive layer around the perimeter of the lid; a regular hair dryer may not give the desired temperature.
- 🎴 Medical scalpel or thin mediator: for gently detaching the cover after heating; metal blade must be very thin.
- 🧲 Magnetic mat or organizer: for sorting screws of different lengths, so as not to confuse them when assembling.
Special attention should be paid to the choice of heating appliances: the use of open fires or too powerful industrial hair dryers without temperature adjustment is unacceptable. Overheating of plastic can cause its deformation or color change, as well as damage the internal components, such as a camera or display module. The optimal temperature of heating the surface of the lid is 80-90 degrees Celsius.
It is also recommended to have a screen suction cup on hand, although in the case of Redmi 3 it plays a supporting role. The main work of singing (separating) the layers will be done by a thin blade that penetrates the heated glue. If you do not have a professional suction cup, you can use special sticky tapes, but you need to act extremely carefully.
The process of dismantling begins with the removal of SIM-This is a standard safety procedure to avoid damage to contacts or data loss in the event of an unexpected power surge, although the risk is minimal when the device is turned off. After that, the phone is placed on a soft, clean surface with the screen down so as not to scratch the display during operation.
The first step of mechanical action is to heat the perimeter of the back cover. Turn on the hair dryer and evenly warm the ends of the smartphone for 2-3 minutes, constantly moving the flow of hot air. The adhesive layer should soften, but not melt completely. You can check readiness carefully trying to tamper with the angle with the blade: if you feel strong resistance, the heat should continue.
Once the glue is heated, a thin tool comes in. Put the scalpel blade or mediator into the junction between the frame and the lid, starting at the bottom corner near the charging socket. The movements should be sliding, parallel to the plane of the lid, not perpendicular to it, so as not to pierce the battery. Gradually move around the perimeter, hearing the characteristic crackling of the adhesive.
⚠️ Warning: Don't try to pull the lid off with a jerk! the glue can come off unevenly and a sharp movement will result in a crack on the plastic panel or worse, damage to the main camera plume, which is often glued to the inside of the lid.
Once you've walked around the perimeter, the lid should be easy to remove. But there's an important caveat in the Redmi 3: the fingerprint scanner plume (if it's modified) or the bottom board plume can be glued to the lid. A sharp opening at a large angle is guaranteed to cause the contact to break. Act slowly, controlling the tension of the internal connections.
When you remove the lid, don't put it too far. In some device revisions, the antenna terminals can be integrated into the lid structure, and losing this element will render the phone inoperable in communication networks. Visually inspect the interior of the removed part for the integrity of the contact areas.
Now we have the inside of the smartphone, protected by a metal screen or a plastic pad that covers the motherboard. In Redmi 3, the main board is covered by a metal plate that is mounted with multiple screws. They need to be twisted using a previously prepared cross screwdriver. The screws can be of different lengths, so it is extremely important to remember or record their location.
☑️ Readiness to charge
The next critical step is to turn off the plumes. Carefully bend the protective bar if it interferes with access to the connectors. Xiaomi plumes are usually fixed with pinch slats or simply tightly inserted into the connector, you need to poke them strictly behind a special tongue, if you have one, or very carefully along the edges of the connector, avoiding pressure on the connector itself on the board.
The plume that connects the mainboard to the lower board (where the charging connector is located) requires special attention. It often runs under or along the battery. In Redmi 3, this plume is wide enough and requires delicate handling. You also need to turn off the connector of the battery itself. Use a plastic blade to avoid closing the battery contacts with a metal tool.
Once you shut down all communications, you can remove the metal screen that covers the CPU and RAM, and underneath that you'll see the basic logic of the device, and if your goal was just to replace the battery, you don't have to remove that screen, but it might be necessary to fully access the bottom of the case and replace the charging connector, and in the context of removing the back cover, we've already reached the main thing: access to the insides.
When you reverse assemble, the reverse is the exact opposite: first you plug in the plumes, then you screw in the metal protection, and then you check the device before you finally stick the lid, and don't rush to apply the new glue right away until you make sure the phone turns on and responds to the touchscreen.
| Work phase | The necessary tool | Critical risk | Implementation time |
|---|---|---|---|
| Perimeter heating | Fen/Thermolament | Overheating of the display or battery | 2-3 minutes |
| Perimeter opening. | Scalpel/Spaddle | Finger cut/Steil damage | 5-7 minutes |
| Shutting down the plumes | Plastic spatula | Breakage of the plume or connector failure | 2-3 minutes |
| Removal of protective screens | Phillips screwdriver #00 | Thread failure or loss of screws | 3-5 minutes |
One of the common problems with Redmi 3 The thing is, the camera module is very close to the edge, and inexperienced craftsmen, if they put the blade too deep, cut it, and if they do, the camera will stop working, and they'll need to replace the module, which will make it much more expensive to repair. The depth of penetration of the blade under the cover should not exceed 2-3 millimeter.
Another important point is the state of the screws: in older devices, they can be acidified or covered with a layer of dust and oxides. If the screw does not twist, do not use excessive force to avoid breaking the hat. You can drip (very little) alcohol or special solvent, wait a minute and try again. The use of WD-40 lubricant inside the smartphone is strictly prohibited because of its aggressiveness to plastics and the possibility of closure.
What to do if the plume is broken?
When installing a new battery or assembling a device, make sure all the plumes are in their channels and are not clamped anywhere. A clamped plume may work at first, but when heated or vibrated, contact will disappear. The space inside the smartphone in Redmi 3 is quite dense, and every millimeter here matters.
To fix the lid back, it is recommended to use a special glue B-7000 or T-8000. You need to apply it with a thin strip along the perimeter of the frame, avoiding hitting the camera lens, speaker and connector. After pressing the lid, it is advisable to put the phone under the press (for example, under a stack of books) for 1-2 hours for complete polymerization of the glue.
⚠️ Warning: Don't use superglue (cyanacrylate) to stick the lid! It highlights the fumes that settle on the camera's lens and make the photos cloudy, and also makes the plastic brittle and brittle the next time you disassemble.
When you finish the procedure, wipe the case of glue residues and fingerprints. Cleanliness inside the device is a guarantee of its long service, as dust can cause overheating or poor contact. Make sure that all screws are twisted evenly, without distortion.
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Use tape or special stickers to fix the battery plume when installing a new battery so that it does not hang around inside the case.
Disassembling the Xiaomi Redmi 3 is a task that requires patience and a firm hand. Although the device is not the most complex, the dense layout and adhesive joint dictate the rules. The main thing is not to rush and warm up the glue thoroughly before each movement of the tool. A correctly executed replacement will allow your smartphone to last for many years, delighting autonomy.
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High-quality dismantling of Xiaomi Redmi 3 is impossible without preliminary heating of the body and the use of thin, sharp tools to dissect the adhesive layer.