Xiaomi Mi Note 3 is the iconic smartphone of 2017, which is still in demand due to its powerful hardware and stylish design. However, over time, even the most reliable equipment requires repairs, from replacing the battery to cleaning the connectors. If you decide to disassemble the device yourself, this article will help you avoid the typical errors that lead to damage to plumes, cracks in the case or loss of warranty (if it is still valid).
We'll go through the whole process in detail, from tool preparation to reassembly, and tell you what hidden latches and adhesives the manufacturer has hidden under the back cover, and we'll focus on the risks of why you can't use metal mediators, how you can't damage the fingerprint scanner, and what to do if the screen doesn't turn off when you disassemble.
The instructions are suitable for all Mi Note 3 versions (including the global version), but note: if your device has been repaired before, the internal layout may differ (for example, a replaced battery or plumes).
Preparation for disassembly: tools and security measures
Before you start, make sure you have everything you need. Xiaomi Mi Note 3 is not the most difficult to disassemble smartphone, but it requires care due to the fragile plumes and adhesive battery attachment.
- 🔧 Plastic mediators (2-3 pieces) - to separate the body. Metal can scratch the frame!
- 🔨 The screwdriver. PH00 — for the rear cover screws (normal) PH0 It's too big, it's too big).
- 🔋 Suction - to adjust the screen (if you need to remove it).
- 🧴 Isopropyl alcohol (90%+) — Cleaning contacts and removing glue residues.
- 📦 A screw tray or magnetic substrate – so as not to lose small details.
- 🔥 Hair dryer or thermoair station - for softening the glue (optional, but simplifies the process).
Also, prepare the workspace: it should be well lit, dust-free (small particles can get inside the case) and antistatic (for example, a rubber mat). If you take your smartphone apart for the first time, take a picture of each step, which will help with the reverse assembly.
⚠️ Note: If your Mi Note 3 was in water or fell from a height, disassembly may result in a short circuit due to oxidized contacts.
Step 1: Remove the back cover – where are the latches hidden?
The back cover of the Mi Note 3 is attached to glue and latches. To remove it, first turn off the smartphone (if it turns on) and remove the tray for the camera. SIM-Then you go with the algorithm:
- Heat the edges of the body with a hairdryer (temperature) ~50–60°C) for 1-2 minutes. This will soften the glue.
- Insert the plastic mediator into the gap between the lid and the frame (start at the lower right corner where the Type-C connector is located).
- Carefully drive the mediator along the perimeter, alternately snapping the locks, 12 of them: 3 on each side and 3 in the upper / lower parts.
If the lid doesn't lend itself, don't force it -- you've probably missed the latch. Check the angles, they often stick harder there. When the lid moves 1-2mm, suction it with a suction cup and slowly lift it.
☑️ Checklist before lid removal
| Phase | What could go wrong? | How do you avoid it? |
|---|---|---|
| Heating with a hair dryer | Overheating of the battery or display | Keep the hair dryer at a distance of 10 cm, do not heat one point longer than 10 seconds |
| Clicking by mediator | Scratches on a frame or chipped plastic | Use only plastic tools, without jerking. |
| Suction lid lift | Damage to the fingerprint scanner plume | Don’t pull the lid sharply – the plume comes from the top edge! |
Step 2: Shutting off the battery – why is it critical?
When you remove the lid, the first thing you do is turn off the battery, which prevents you from shorting when you accidentally touch the board. In the Mi Note 3, the battery connector is on the lower left (if you look at the board), and it's covered with black insulation tape -- tweez it carefully.
To disconnect the plume, lift the white plastic latch (it fixes the connector) and pull the plume up. Don't pull the wires, just the connector itself! If the battery is swelling, don't try to remove it yourself: the risk of fire when punctured is extremely high.
💡
If the latch of the battery connector broke, temporarily fix the plume with tape so that it does not go away when vibrating.
⚠️ Warning: If the battery is turned off, the phone still turns on when you press the power button, the capacitors on the board are still charged. Wait 5-10 minutes or touch the metal part of the screwdriver. GND (on board to discharge them.
Step 3: Motherboard Removal – Where are the “surprises” hidden?
The board in the Mi Note 3 is mounted on 10 screws (of different lengths!) and one plume, the antenna coaxial cable. Before you take it out, take a picture of the screws' location: if you confuse them with places, you can damage the board or the body.
Procedure:
- Unscrew all the screws (start with the longest ones – they hold the metal screen over the board).
- Disconnect the plumes: 📱 Display (in the center of the upper edge of the board). 👆 Fingerprint scanner (thin plume on the right). 🔊 Speaker and microphone (lower left corner).
Carefully raise the margins, starting at the top.
Notice the two rubber pads under the board, which protect the antennas, and when you assemble them, you have to put them back in place, otherwise the Wi-Fi and LTE signal will deteriorate.
What to do if the screw breaks?
Step 4: Replace the battery – how not to damage the controller?
The battery in the Mi Note 3 is glued to the body with double-sided tape, which requires patience and isopropyl alcohol (it dissolves glue), and an alternative is a special device for removing batteries (sold in tool stores).
Step-by-step:
- Put a plastic shoulder blade on the battery from any angle.
- Drain the alcohol under the battery and wait 1-2 minutes until the glue is softened.
- Pull the black band slowly, applying a force parallel to the body. Don't lift the battery vertically, you can tear off the plume!
- After extraction, clean the contacts of the board and the case of glue residues.
When installing a new battery, use a new two-way tape (companying with the battery) to make sure the plume is not bent or stretched - this can lead to loss of communication with the charging controller.
💡
Never use metal objects to smack the battery – the risk of puncture and fire is extremely high!
Step 5: Screen Disassembly – When is it Necessary?
Removing the display module in the Mi Note 3 is rarely required, usually when replacing the touchscreen or the matrix, but if the screen cracks or stops responding to touch, this is necessary. The main difficulty is the plume of the fingerprint scanner, which goes through the entire body and easily tears.
Algorithm:
- Heat the screen with a hair dryer (temperature ~70°C) around the perimeter.
- Suction the display from the bottom edge (there are no plumes).
- Put the mediators in the slot and carefully separate the screen and the frame. The plumes are located at the top - don't pull the display too far!
- Disconnect the display and touch screen plumes (they are fixed by latches).
Another common problem is a broken speaker after assembly, usually because of a misconnected plume or a forgotten screw that presses on the contacts. Always check the sound before final assembly!