Modern wearables like the Xiaomi Mi Band 4 are designed to be as tight and compact as possible, often making them almost disposable in the eyes of the average user. However, when a battery fails or a display breaks, the owner is faced with the question of whether to repair it. It is difficult to disassemble the device, but it is possible with the right tools and a clear understanding of the internal architecture of the device.
The opening process requires jewellery precision, as there is no free space inside the fitness tracker and all components are planted on glue. Any careless movement can damage the plume or puncture the battery. In this article, we will look in detail at the dismantling steps, the necessary tools and the potential risks you may face.
Before you start taking action, you need to evaluate your skills with small electronics. If you have never held a soldering iron or thin tweezers, you may want to consider handing the device over to professionals. However, if you are determined to reanimate the gadget yourself, follow our recommendations carefully.
Preparation of the workplace and tools
The success of any electronic repair operation depends 90 percent on the quality of the preparation. You'll need a specialized toolkit to work with the Mi Band 4, because standard appliances won't work here, and the main challenge is to fit the module tightly into a silicone strap and use adhesives to fix the screen.
You'll need a thin metal scalpel or a special knife to open the case, a plastic spatula (spooger), a dryer to heat the glue and tweezers with curved ends. Also, don't forget about a suction cup that will help separate the display from the frame without excessive physical effort. All manipulations are best done on a well-lit table with an antistatic mat.
- 🔧 Thin scalpel or blade for cutting glue.
- 🌡️ Hair dryer or thermoplatform for heating the body.
- 🧲 Tweezers and plastic spatula for safe opening.
- 🔋 New battery or screen replacement.
Pay special attention to lighting: small parts and plumes are not visible in dim light, which increases the risk of error. Use a lamp with the ability to adjust the brightness and angle of inclination. The heating temperature should not exceed 80-90 degrees Celsius, so as not to melt the plastic or damage the display matrix.
⚠️ Warning: Never use an open fire (lighters, candles) to heat the case, as this is guaranteed to deform plastic and soot.
Removal of the module from the strap
The first step is to remove the main module (capsule) from the silicone strap. Unlike previous versions, the Mi Band 4 sits tightly enough in the seat, but not glued to the strap itself. The main goal is not to damage the charging contacts on the bottom of the device.
Turn the bracelet downwards and put your thumb on the convex part of the capsule on the back side, while pulling the module out of the strap hole, and if the device is sitting tight, you can stretch the silicone slightly with your fingers to make it more elastic.
💡
Lubricate the inside of the strap with talc or baby powder before re-installing the module - this will facilitate future extraction and prevent dust from sticking.
After removal, carefully inspect the body for cracks or chips. Even microscopic damage to the frame can disrupt the IP68's declared moisture protection. Make sure the buttons and touch areas are clean before further disassembly begins.
Technology of opening the body and screen removal
The most critical thing is that you split the screen and the back cover, and the Xiaomi Mi Band 4 is glued around the perimeter, and you can't just open it, and you're going to need to warm the perimeter evenly with a hairdryer for 2-3 minutes, and that's going to soften the adhesive layer.
After heating, insert a thin blade of the scalpel into the junction between the display and the frame. Move slowly, making cutting movements along the perimeter, trying not to plunge the blade deeper than 1-2 mm so as not to damage the insides. Gradually increase the gap by inserting a plastic blade.
☑️ The opening process
When the glue is cut all around the circle, gently lift the display up, and underneath it you'll see a plume connecting the screen to the motherboard, which is very thin and fragile, so it requires the utmost care when you turn it off.
⚠️ Warning: Don't pull the screen upwards! First make sure the plume is disconnected from the connector on the board, otherwise you're guaranteed to tear the contacts.
Access to battery and control board
When you take off the screen, you'll see the inside of the gadget, and you'll see the motherboard in the center, and a lithium polymer battery underneath or near it, and in the Mi Band 4, the battery is often glued to the bottom of the case or to the board itself.
To replace the battery, it needs to be carefully unstuck. Use a plastic card or a spatula to smack the edge of the battery. Metal tools are dangerous to use here, you can break through the battery shell, which will cause a fire or a chemical reaction.
| Component | Function | Risk of damage | Difficulty replacing |
|---|---|---|---|
| AMOLED screen | Display of information | Tall (fragile glass) | Medium |
| Battery | Powering the device | Critical (fire risk) | Tall. |
| Vibromotor | Notifications | Low. | Low. |
| Fee (PCB) | Management of systems | Critical (death of the gadget) | Tall. |
If you want to replace the vibrator or clean the contacts, you may not need to take a deep disassembly, but you'll have to take the entire board out of the case to replace the battery. Notice the location of the antenna, which is often made in the form of perimeter wiring.
Where's the antenna?
Replacement of the display and assembly of the device
The build process is reversed, but it has its nuances. The new display for the Mi Band 4 needs to be checked for performance before the final sticker is put in. Connect the plume, temporarily press the contacts and apply power.
If the image appears and the touchscreen reacts, you can start fixing, the residue of old glue from the frame must be carefully removed with alcohol or isopropyl alcohol, the surface must be perfectly clean and fat-free.
To fix the new screen, use a special B-7000 glue or double-sided electronics tape. Apply a thin layer of glue around the perimeter of the frame, avoiding hitting the matrix and the center of the device. Press the screen and lock the device with rubber bands for 1-2 hours until completely dry.
- 🧼 Degrease the frame with alcohol before the sticker.
- 💧 Apply the glue in a thin layer, without bubbles.
- ⏱️ Let the glue dry for at least 60 minutes.
It is important not to overdo it with the amount of glue, otherwise the excess glue can squeeze in and damage the electronics. After assembly, check the tightness, although the factory level of protection is unlikely to be fully restored.
💡
The quality of restoration of moisture protection after self-disassembly is significantly reduced, so it is not recommended to wet the repaired bracelet in water.
Common Mistakes in Mi Band 4 Disassembly
Many users make fatal mistakes in the first minutes of disassembly, the most common being trying to open a cold case. Without preheating, the glue remains solid, and physical effort leads to cracks in the glass or breakage of plastic latches.
Another mistake is to use tools that are too rough, and a thick knife blade can crumbling the edge of the display or damage the oleophobic coating, using only sharpened scalpels or special tools for smartphones.
⚠️ Warning: Do not attempt to charge the device immediately after assembly if you have used glue.Make sure the chemical vapors are completely weathered and the glue is polymerized.
Also worth mentioning is the risk of static electricity: By working with dry cloth or wool, you can accumulate a charge that will disable sensitive electronics, use an antistatic bracelet or periodically touch a grounded metal object.