The Xiaomi Mi Band fitness bracelets have become one of the most popular wearables due to the combination of functionality and affordable price. However, many users are faced with the need to remove the internal capsule (module with electronics) from the strap - whether it is for battery replacement, repair after moisture or just to clean contacts. In this article, we will understand how to do it without damage, what tools you need and what to look for when working with different models of bracelets.
It's important to understand that the design of the capsule and the mechanism of its attachment differ depending on the generation of the Mi Band. 3/4 A plastic fixator is used, and in the Mi Band 5/6/7 — The wrong actions can cause the clamp to break or even damage the flexible plume that connects the display to the board.
If you've never done electronics before, don't worry: the process of removing the capsule doesn't require special skills, the main thing is to act carefully and follow the instructions. In most cases, you just need to have a plastic spatula (mediator) and a little patience. But about everything in order.
Preparation: What will be needed to remove the capsule
Before you start disassembling, make sure you have everything you need. Here is the minimum toolkit that will come in handy for most Xiaomi Mi Band models:
- 🔧 Plastic blade or mediator - for gently polishing the capsule. Metal tools are not recommended, as they can scratch the body or damage the contacts.
- 🧲 Magnetic screwdriver (cross, 1.5-2 mm) - you will need to unscrew the screws in some models (for example, Mi Band 4) NFC).
- 📏 Tweezers – will help to extract small details if the fixture breaks.
- 🔦 Lantern or table lamp – good lighting will make it easier to work with miniature elements.
- 🧴 Isopropyl alcohol (70% and higher) – for cleaning contacts if the capsule is removed due to moisture.
Also, prepare a clean workplace – it is better to cover the table with paper or cloth, so as not to lose small details.
- 🔋 New battery (if you plan to replace) Make sure it is compatible with your bracelet model.
- 🔥 Dryer or soldering station - for welding plumes (only for experienced users!).
- 🧪 Thermopaste – if you need a replacement of the gasket (relevant for Mi Band) 5/6 sensory SpO₂).
Some users try to dispense with tools using their fingernails or credit cards, and it's risky: the plastic case of the bracelet is fragile, and the latches can break if you press it carelessly, and if you don't have the right tools, you'd better buy a cheap phone repair kit, which will come in handy in the future.
Differences in capsule design: Mi Band 3/4 vs Mi Band 5/6/7
Xiaomi's fitness bracelet design has evolved with each generation, and the main changes have been the way the capsule is attached to the strap, and here's a comparison table that will help you understand what you're going to be working with.
| Model | Type of fixator | Difficulty of extraction | Features |
|---|---|---|---|
| Mi Band 3 | Plastic clamp | Low. | The capsule is fixed with two plastic ears, often broken when untidyly removed. |
| Mi Band 4 / 4 NFC | Plastic clamp + screw | Medium | In the c version NFC I've got a screw under the lid. I need a screwdriver. |
| Mi Band 5 | Metal latch | Tall. | The latch is fragile, it can bend when pressed hard, and it is recommended to warm up the body with a hairdryer. |
| Mi Band 6 / 7 | Improved metal latch | Medium | Guide grooves have been added, but the latch still requires accuracy. |
The Mi Band 5 and later use glue to further fix the display, so you have to carefully separate it when you disassemble it, otherwise you can damage the plume, and if you're not sure about yourself, you'd better go to the service center, especially if you have a warranty bracelet.
Another important point: in the Mi Band 4 NFC and Mi Band 5/6/7 And under the capsule lid is a flexible plume that connects the display to the main board, and if you move carelessly, it's easy to tear it off. If you're removing the capsule for repair, prepare the captone tape or thermoglue to fix the plume after assembly.
In some cases (for example, after the bracelet falls), the latch may deform. If the capsule is not fixed in the strap after assembly, you may need to replace the lock.
Step-by-step: how to remove the capsule from the Mi Band 3/4
Let's start with the most popular models, the Mi Band 3 and the Mi Band 4, which are similar in design, but the fourth version adds a screw to the design. NFC-If you have a regular Mi Band 4 (without the usual one) NFC), The instructions will be identical to the third model.
☑️ Preparation for the removal of the capsule Mi Band 3/4
Step 1. Remove the strap.
Turn the bracelet with the back of your head, and you'll see a little groove at the bottom of the capsule, which is the hold, and you'll be able to press it carefully with your nail or a plastic blade in the upward direction (towards the display), and the capsule should be slightly raised.
Step 2: Remove the capsule.
Once the lock is detached, pull the capsule away from the strap (along its axis). Don't put too much effort -- if the capsule doesn't respond, check if the latch is fully pulled. In Mi Band 4, you can use the slack. NFC You will also need to unscrew one screw under the lid (use a magnetic screwdriver so as not to lose it).
Step 3: Separate parts.
The capsule consists of two parts: the front (with a display) and the rear (with a sensor and charging contacts). To separate them, gently apply a plastic blade around the perimeter, starting at the corners. Be careful - there may be spring contacts inside that are easy to bend.
⚠️ Attention: Mi Band 3 often breaks the plastic ears of the locker when it is not carefully removed. If this happens, the capsule can be fixed in the strap using a thin strip of double-sided tape (but this is a temporary solution - it is better to replace the strap).
If you are removing a battery replacement capsule, note: in the Mi Band 3/4 The battery is soldered to the board, and it will require a soldering iron with a thin sting and experience with microelectronics, otherwise you'd better contact the service.
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If the capsule is not removed, try to slightly heat the strap with a hairdryer (no higher than 60).°C) - the plastic will become softer and the hold will be more easily squeezed.
Features of capsule extraction in Mi Band 5/6/7
In the fifth and later generations, Xiaomi has redesigned the hold, instead of using plastic ears, it now uses a metal latch that attaches to the capsule body, which complicates the process but makes it more reliable, but if it is handled carelessly, the latch can bend and the capsule will stop fixing in the strap.
Step 1. Preparation.
Put the bracelet down on the table with the display, and you'll see a small gap at the bottom of the capsule, on the sensor side, where the latch is, and you'll take a plastic blade and you'll gently insert it into the gap, just by gently pressing it away from the strap.
Step 2. Click the lock.
Press downwards (towards the table) while pulling the capsule upwards. The latch should click, and the capsule will come out of the slots. If that doesn't happen, try to move the blade slightly left or right -- sometimes the latch sticks.
Step 3: Disassemble the capsule (if necessary).
In Mi Band. 5/6/7 The capsule's body is glued together:
- Warm up the body with a hair dryer around the perimeter (temperature not higher than 80)°C, so as not to damage the display).
- Carefully tuck the shoulder blade, starting at the corner next to the button.
- Disconnect the plume of the display (it is attached to the connector - do not pull the wires!).
⚠️ Attention: In the Mi Band 6/7 And under the display is a heat pad that provides heat removal from the chip, and when you assemble it, you have to put it back in place or replace it with a new one, or the bracelet will overheat.
If you notice that after you remove the capsule, the button stopped working, it's likely that the contact on the board has gone away, and this is a common disassembly problem, and the button is mounted on a microswitch that can shift, and you'll need to disassemble the capsule and check the position of the switch.
What to do if the latch breaks?
Cleaning contacts and troubleshooting after moisture
One of the most common reasons users remove the capsule from the bracelet is water or sweat. IP68, Over time, the seals wear out and moisture gets inside. If the bracelet stops charging, doesn't turn on or shows incorrect data, you'll probably need to clean the contacts.
What to do:
- Remove the capsule from the strap (as described above).
- Disassemble the capsule body (if possible without damage).
- Check the fee for the presence of oxidation (green or white plaque on the contacts).
- Clean the contacts with isopropyl alcohol (70% or higher) with a cotton swab. Do not use water or acetone!
- Ask for warm air (dryer at minimum power) for 10-15 minutes.
If the bracelet does not turn on after moisture hits, check:
- 🔋 Battery -- it may have swelled or lost capacity, and it'll need a replacement.
- 🔌 Charging contacts -- often oxidized first. They can be cleaned with a swallow or alcohol.
- 📱 Display plume – if the screen does not show the image, but the bracelet vibrates, the problem may be in the disconnected plume.
If the bracelet doesn't work after cleaning, it may have shorted out, and if it's not possible to repair it yourself, you'll need a multimeter diagnostic at a service center.
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After moisture is ingested, you can not immediately turn on the bracelet - you first need to dry the board completely (at least 24 hours at room temperature).
Replacement of the battery: when it is necessary and how to do it
The average battery life of Xiaomi fitness bracelets is 2-3 years. Over time, the capacity decreases and the bracelet begins to run out in a few hours.
- 🔋 The bracelet keeps the charge less than a day (in normal use).
- 📉 The percentage of charge "jumps" (for example, from 50% immediately drops to 10%).
- ⚡ The bracelet is not turned on after full discharge.
It is likely that the battery will need to be replaced.
How to replace the battery:
- Remove the capsule from the strap.
- Disassemble the body (as described above for your model).
- Solder off the old battery using a soldering iron with a thin sting. Be careful - the battery may swell!
- Salt a new battery, observing the polarity (+ and −).
- Seal the battery with capton tape to avoid short circuit.
- Put the bracelet in reverse order.
Where to buy a battery:
- 🛒 AliExpress - search for "Mi Band [your model] battery" cost from 300 to 800 rubles.
- 🏬 Electronics parts stores – for example, Chip & Deep or local service centers.
- 🔧 Service centers – some offer a turnkey battery replacement".
⚠️ Warning: Never overheat the battery when soldering - this can cause bloating or even fire. Use a soldering iron with a power of no more than 30 watts and work with short touches.
If you are not sure about your soldering skills, it is better to entrust the replacement of the battery to professionals. The cost of working in service centers usually does not exceed 1000-1500 rubles, which is cheaper than buying a new bracelet.
Frequent Mistakes and How to Avoid Them
Even with careful work, there is a risk of making a mistake that will cause the bracelet to break, and here are the most common problems and ways to prevent them:
| Mistake. | Effects of consequences | How to avoid |
|---|---|---|
| Use of metal tools | Scratches on the body, damage to contacts | Use only plastic shoulder blades or mediators |
| Too much pressure on the lock | Breakdown of plastic "ears" or metal latch | Press smoothly, without jerking. If you can't, warm up the body with a hair dryer. |
| Disassembly without disconnecting from charging | Short circuit, board failure | Always disconnect the bracelet from the charger before disassembling |
| Using superglue to fix the capsule | The hit of glue on the contacts, the impossibility of further disassembly | For temporary fixation, use double-sided tape. |
| Battery soldering without protection | Bloating or ignition of the battery | Work in a ventilated room, use safety glasses |
Another common mistake is the wrong build, like forgetting to plug the display plume into the Mi Band. 5/6/7, The bracelet will turn on, but the screen will remain black:
- 🔌 Are all the plumes and connectors connected.
- 🔋 Is the battery installed correctly (polarity!).
- 🛡️ Are there any foreign objects inside the case (scotch clippings, dust).
If the bracelet doesn't turn on after assembly, don't panic. The battery may have run out to zero. Connect it to charge for 10-15 minutes, and then try to turn on the button. If that doesn't work, check the multimeter voltage on the battery contacts (should be ~3.7–4.2).