Disassembly Xiaomi Mi Band 2: how to open the body of the bracelet without breakdowns

The 2016 Xiaomi Mi Band 2 fitness bracelet is still popular with users due to its simplicity, reliability and low price. However, over time, even such a durable device can fail: it stops holding the charge, does not sync with the smartphone or requires a battery replacement. In most cases, repair is possible on its own, but you need to carefully disassemble the case without damaging fragile internal components.

In this article you will find a step-by-step instruction with a photo, a list of necessary tools, as well as unique tips for disassembling without scratching on plastic - a problem faced by the police. 80% We're also going to look at the common mistakes that cause the display to break or the plumes to break off, and we're going to talk about how to avoid them. 2 Stop working, don’t rush to throw it away. 90% In some cases, it can be restored for 20-30 minute.

Preparation for disassembly: tools and precautions

Before you start disassembling, make sure you have everything you need, and the lack of the right tools is the main cause of damage to the body or internal parts, and here is the minimum kit you'll need:

• 🔧 Plastic blade (or mediator) - for gently putting the lid on. Metal tools will leave scratches!
• 🔥 Hair dryer or thermo-air station - for softening the glue (temperature not higher than 60)°C).
• 🧲 Magnetic screwdriver (cross, size) PH00) — squirt.
• 📦 Container for parts - so as not to lose small screws and springs.
• 🧴 Isopropyl alcohol (90%+) — glue-residue.
• 📸 Smartphone with camera – to photograph the process (useful when backassembling).

Take a special care of the workplace. Take apart the bracelet on a clean, well-lit surface, preferably on an antistatic mat (if not, at least on a table without carpeting), static electricity can damage the chips, and prepare a toothpick or needle, which will help to smear small parts.

⚠️ Warning: Do not use a knife or screwdriver to lash the lid! Even a small effort can lead to cracks in the plastic or damage to the flexible plume of the display. If the plastic blade does not cope, warm up the case with a hairdryer.

Step 1: Removal of the strap and preparation of the body

Start by removing the silicone strap.

1. Turn the bracelet down with the display.
2. Find a small plastic latch on the back of the strap (it is located closer to the edge).
3. Carefully press the latch towards the body and pull the strap upwards. It should come out of the slots effortlessly.

After removing the strap, you will see two screws under the cross screwdriver (size) PH00). They need to be twisted, but not to the end - it is enough to weaken the 2-3 Complete unscrewing at this stage can cause internal parts to fall out!

Remove the strap from the latch|Weakening (not twisting!) two screws on the back|Hair-dryer (60°C, 1-2 minute)|Prepare a plastic shoulder blade for underdoping-->

If the screws don't respond, don't force them -- they're probably stuck with moisture. WD-40 Or isopropyl alcohol, wait 5 minutes and try again. Don't use superglue or other aggressive solvents, they can damage the plastic.

Step 2: Separating the body into two parts

The most critical step is to disconnect the front and back, and there are many users who make mistakes that cause the latch to break or the plume to break.

1. Warm up the body with a hair dryer around the perimeter during 1-2 It'll soften the glue that glues the halves together. 60°C - otherwise the display will be damaged.
2. Insert the plastic shoulder blade into the gap between the front and back (start with the side opposite the button).
3. Carefully drive the blade along the body, gradually increasing the gap, and you will hear the characteristic clicks - this is the internal latches.
4. Once the gap is wide enough, do not pull the spatula out – move it to another area and repeat the procedure.

If the body doesn't respond, don't increase the force, you better warm it up with a hair dryer again. A typical mistake is to try to break the halves apart with a jerk, which leads to a break in the flexible plume connecting the display to the board, or damage to the vibrating motor.

Step 3: Extract the internal components

After the separation of the body, you will see three main components:

• 📱 Display module - is mounted on a flexible plume to the main board.
• 🔋 Battery (capacity 70 mAh) - glued to the back cover.
• 🔊 Vibration motor – located next to the battery.

First thing you do is unplug the display plume.

1. Carefully put a black connector on the board (it is fixed with a latch).
2. Use a plastic shoulder blade or nail to lift the latch up.
3. The plume should come out without effort. Don't pull it! -- if it doesn't, check if the latch is fully removed.

Next, unscrew the four screws holding the board (they can be hidden under stickers). After that, the board will easily separate from the back cover. The battery is glued - to remove it, warm up the back cover with a hairdryer (temperature to 50).°C) and gently apply a plastic blade.

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If the battery is swelling, don't try to puncture it! This can cause fire. Instead, place the bracelet in a sealed container and dispose of it at the battery point.

Step 4: Diagnostics of malfunctions

Now that all the components are removed, you can start looking for the cause of the failure, and here are the most common Mi Band 2 malfunctions and their signs:

To check the battery, connect the multimeter in the constant voltage measurement mode (DC) The normal voltage of the charged battery is 3.7-4.2 V. If the value is below 3.0 V, the battery is to be replaced. Also check the charge for darkened or bloated capacitors is a sign of short circuit.

⚠️ Warning: If the board has traces of oxidation (green coating), do not clean them with alcohol or water! Use citric acid (5% solution) and a toothbrush with soft bristles. After cleaning, wash the board with distilled water and dry with a hair dryer.

Step 5: Replace the battery or other components

If the diagnosis showed that the problem is in the battery, it can be replaced yourself. For the Mi Band 2, the 301230 battery with a capacity of 70-80 mAh is suitable.

• 🔋 The sizes must match the original (30×12×3 mm).
• 🔌 Presence of protective film on contacts (prevents short circuit).
• 📏 The length of the wires – they should not be shorter than the original.

Replacement procedure:

1. Solder off the old battery by warming the contacts with a soldering iron (250-300)°C) and gently kick her with a spatula.
2. Clean the contact areas on the solder board with a soldering braid.
3. Sell a new battery while observing polarity (red wire — "+", black — "-").
4. Secure the battery on double-sided scotch or glue B-7000.

To replace the display or vibration motor, you need to completely disassemble the display module, attach to the board through the connector, and the motor with two soldered contacts, RMA-223) and soldering iron with a power of not more than 30 W, so as not to overheat the board.

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When replacing the battery, be sure to check the integrity of the protective diode (marking) D1 It's broken, and it's a common cause of rapid discharge after battery replacement.

Step 6: Build the bracelet and check the performance

The Mi Band 2 is assembled in reverse order, but with a few nuances in mind:

1. Check all plumes and connectors - they should be tightly connected, without distortion.
2. Put a thin layer of glue on the edge of the body before you put the halves together. LOCTITE 401 or B-7000.
3. Twirl the screws cross-cross to avoid skewing the body.
4. Warm up the body with a hair dryer (40-50)°C) after assembly - this will accelerate the polymerization of the adhesive.

Once assembled, connect the bracelet to the charger, if it does not turn on:

• 🔌 Check the polarity of the charging cable connection (contacts must match the sites on the board).
• 🔋 Make sure the battery is connected correctly (the voltage on the contacts should be 3.7-4.2 V).
• 📱 Reboot the bracelet by holding the touch button for 10 seconds.

If the bracelet is turned on but not synced with the smartphone, reset it to factory settings via the Mi Fit app:

Settings → Mi Band 2 → Additional → Resetting settings

Frequent Mistakes and How to Avoid Them

Even experienced users sometimes make mistakes when disassembling the Mi Band 2. TOP-5 The most common problems and ways to prevent them:

Pay special attention to the plume of the display, which is attached to the board through a fragile connector, which is easily damaged. If the screen does not work after assembly, check:

• 🔍 Integrity of the plume (whether there are breaks or breaks).
• 🔌 Correct connection of the connector (latch must be fixed).
• 📱 The performance of the display on another board (if there is a spare).

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If the bracelet discharges quickly after replacing the battery, check the consumption current in sleep mode. Norm - no more than 0.01 mA. Exceeding indicates a leak (possibly damaged charging controller).

FAQ: Answers to Frequent Questions