Modern wearables such as the Xiaomi Mi Band 3 are designed with minimal dimensions and high moisture protection, making disassembly difficult for the untrained user. The tracker design does not initially involve easy dismantling, so any intervention requires accuracy, special tools and understanding of risks. Owners often face the need to open the device when the battery fails or if the protective glass is damaged.
The process of disassembling the Mi Band 3 is radically different from working with classical electronics, where you just need to unscrew a few screws. Here the main fastener is a powerful industrial glue that holds the body parts together. Wrong actions can lead to tearing of the plumes, damage to the tightness or complete failure of the touch screen, so it is important to follow proven techniques.
In this article, we will discuss in detail the steps of dismantling the capsule from a silicone strap, heating the case to soften the glue and safely extracting the internal components. You will learn what tools are necessary for work, how to avoid typical errors and what to do if the device stopped responding to charging. Careful study of the instructions will help save money at the service center or make an informed decision about the feasibility of repair.
Tools and workplace preparation required
Before any electronic manipulation begins, a suitable space must be arranged.The desktop must be well lit so that you can distinguish between fine details and thin plumes. Dust and static electricity are enemies of chips, so it is recommended to use an antistatic mat or just a clean surface without pile.
To successfully disassemble the Mi Band 3, you will need a specific set of tools that are not always in a standard home medicine cabinet. The main tool will be a dryer to heat the adhesive layer, but it is important not to overheat the device so as not to damage the lithium polymer battery, you will also need thin plastic blades, a glass suction cup and tweezers with curved ends.
Metal tools such as knives or screwdrivers are highly undesirable in the initial stages. Metal can easily slip and break through the display matrix or damage the battery contacts, which will lead to short circuit. Plastic in this regard is safer, as it bends and does not scratch the inner surfaces of the case.
- 🔧 Hair dryer construction or household (to heat glue to 80-100 degree)
- 🛠️ A set of plastic mediators or shoulder blades for opening
- 🧲 Thin tweezers and screen suction cup
- 🧴 Isopropyl alcohol or special adhesive solvent (optional)
Prepare a small-part folding container if your model has screws, although Mi Band 3 doesn't usually have any. Make sure you have a light source that you can point to the side to see the gaps between the case and the screen. Safety is the number one priority, so make sure the device is off before work begins.
☑️ Ready to disassemble Mi Band 3
Removing the tracker from the silicone strap
The first step will be to release the main capsule from the silicone frame. Xiaomi Mi Band 3 strap is made of a hypoallergenic elastomer that tightly fits the body to provide moisture protection. Many users try to squeeze the tracker with their nails, which often leads to breakage of the nail plate or damage to the side faces of the device.
There's a proven method to remove the capsule without damage, and you have to turn the strap inside out by pushing your thumb on the inside of the tracker, and silicone is elastic, and with enough force, it allows the capsule to jump out, and if you don't have enough fingers, you can use a blunt object with a wide contact area.
⚠️ Warning: Never use sharp objects (knives, scissors) to cut the strap if you plan to use it again. Silicone breaks easily under load, and one wrong move can make the accessory unusable.
Once removed, inspect the body for visible cracks or chips. If there is damage to the glass, further disassembly requires special care, since the fragments can damage the internal components. The integrity of the housing directly affects the ability to reassemble and maintain moisture protection properties.
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To facilitate the removal of the capsule, you can slightly warm the strap with a hairdryer at minimum power for 10-15 seconds, the silicone will become softer and more elastic.
Heating of the body and softening of the adhesive layer
The most critical part of the Mi Band 3 disassembly process is the separation of the screen from the plastic body. Manufacturers use a durable glue that freezes at room temperature and becomes elastic only when heated, and without first warming up, trying to tamper with the screen will lead to its guaranteed destruction.
Use a dryer by setting the average temperature of the airflow. Direct the jet of hot air perpendicular to the front panel of the device for 2-3 minutes. Periodically check the temperature with your finger: the surface should become hot, but not burning. Overheating is dangerous by bloating the battery, which can lead to fire or a chemical reaction.
The uniformity of the heating is a key factor in success. Don't keep the hair dryer in one spot for too long, drive it in circular motions throughout the screen area, which will ensure that the glue is softened around the perimeter, not just in the center, and if the glue stays hard in the corners, the glass will burst when you open it because of the uneven voltage.
- 🌡️ Keep the hair dryer at a distance. 5-7 sm
- ⏱️ Warm up the body for at least 120 seconds
- 🖐️ Check the heating with the back of your hand.
- 🚫 Avoid local overheating in the battery area
After warming up, let the device cool down a little for 10-15 seconds so that the plastic isn't too soft, but the glue remains viscous. At that point, you can start creating the first gap. The optimal heating temperature for the Mi Band 3 glue is about 85-90 degrees Celsius.
Technology of accurate opening of the body
To open, use a thin plastic card or a special spatula. Insert the edge of the tool into the gap between the screen and the frame, which is usually at the bottom of the tracker or in the area of the dynamic microphone. The movements should be sliding, not stabbing, so as not to push the display matrix.
Move around the perimeter of the device, slowly dissecting the adhesive layer. If you feel strong resistance, do not use force, this is a signal that the glue in this place has not yet warmed up. Repeat the heating procedure for the problem area. The screen of the Mi Band 3 is very fragile and connected with a plume to the main board, which is easy to break with a sharp jerk.
The opening process may require the use of a suction cup, attach it to the screen and pull it up slightly, creating tension while simultaneously working as a perimeter blade, which will help control the gap and prevent the tool from slipping, and it is important not to open the body completely immediately, since the trains may remain connected inside.
⚠️ Warning: If you have a characteristic cod or burn smell, stop heating and pressure immediately, which may indicate the beginning of battery failure or damage to the insulation of internal wires.
When the glue is cut all around the perimeter, you can gently lift the screen. Don't pull it far away from the body, inspect the insides. In the Xiaomi Mi Band 3, the display can be connected to the board through a short plume that requires careful handling. Use tweezers to turn off the connector if the design allows.
What if the screen cracked at the opening?
Diagnostics of internal components and battery replacement
After a successful opening, you'll see an internal board with the main components, and most often, repairs are required to replace the battery, which loses capacity over time, and the battery in the Mi Band 3 is soldered to the board with two thin wires, which requires soldering iron skills.
To retrieve the battery, carefully bend the locking elements (if any) and solder off the contacts. It is important to observe polarity: red wire usually corresponds to plus, black wire - minus. Polarity confusion when installing a new battery can burn the power controller or the processor tracker.
| Component | Function | Frequency of breakdowns | Difficulty replacing |
|---|---|---|---|
| Battery | Powering the device | High (wear and tear) | Medium (sweatering) |
| Vibromotor | Notifications | Medium | Low. |
| Screen plume | Image transmission | Low. | Tall. |
| Touch panel. | Management | Medium (cracks) | Tall. |
If the battery wasn't the problem, check the charging contacts. They're often oxidized by sweat or water. You can clean them with a cotton swab dipped in alcohol. Reconnecting the contacts often brings the device back to life without having to replace expensive components.
Assembly of the device and checking leakage
The Mi Band 3 is assembled in reverse order, but with a new adhesive composition. Old adhesive is better removed completely from the frame with alcohol or solvent, degrease the surfaces. For gluing, you can use a special glue B-7000 or double-sided thin tape, cut into the shape of the body.
Apply a thin layer of glue to the frame, avoiding hitting the display and speaker. Attach the screen and press tightly around the perimeter. For fixation, you can use stationery gums or special clips, leaving the device to dry for 1-2 hours. Full polymerization of the glue takes up to 24 hours, so in the first hours it is better not to use the device.
Once assembled, make sure to check all the functions of touch, vibration, display and charging. If the tracker is activated and responds to commands, you can consider the repair a success. However, it is worth remembering that factory sealing (IP67/IP68) after self-opening, usually does not recover completely.
- 🧼 Degrease the surfaces before gluing
- 🧴 Use the glue. B-7000 analogue
- ⏳ Let the glue dry for at least 2 hours
- 🧪 Check the sensor and vibrations
It is not recommended to immerse the self-assembled bracelet in water, even if there are no visually slits. The glue seam can be microscopically thin, and the water pressure when swimming easily violates it. Use the device with caution, avoiding direct contact with water.
⚠️ Warning: After assembly, the device may heat up during the first charge. If the heating becomes excessive or the back cover swells, immediately disconnect the tracker from the charger - this is a sign of a battery defect or short circuit.
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Quality assembly depends on the purity of the glued surfaces and the time of drying of the glue, so do not rush to use the device immediately after fixing.