Disassembling the Xiaomi Mi Note 3 is a complex and painstaking process that requires maximum concentration and the presence of a specialized tool. Unlike the more simple models, this device has a fully assembled adhesive-based body, which greatly complicates access to the internal components. Any careless movement can damage the rear window or plumes, so the preparatory stage needs to be given special attention.
The challenge is that the manufacturer didn't provide a screw mount for the back cover, relying solely on the adhesive layer, which improves the sealability and aesthetics of the device, but makes repairs time-consuming. Before you start, you need to make sure that you have all the necessary tools and consumables for subsequent assembly.
If you're not sure about your abilities, you should contact the service center, because self-disassembly automatically deprives you of warranty. However, if the device has already left the warranty or requires an urgent replacement of the component, following this instruction will help minimize the risks. The main rule is to take your time and act consistently, warming up the glue before each movement.
Preparation of the workplace and necessary tools
Before you start disassembling Xiaomi Mi Note 3, you need to organize a comfortable and well-lit workplace. Bright light is critical, as many screws and connectors are tiny and can get lost on the table. It is recommended to use an antistatic mat to eliminate the risk of damage to electronics by static discharge.
You will need a specialized set of tools, without which safe disassembly is impossible. The use of improvised tools, such as knives or pins, is strongly discouraged, as they can damage the inner layers of the body.
- 🔥 Hair dryer or thermal professional heating pad for softening glue.
- 🔧 Precision screwdriver kit (cross-hatch) P2, P5).
- 📱 Plastic mediators and suction cup for opening the body.
- 🧲 Magnetic mat or organizer for screws.
It is also important to prepare a container with isopropyl alcohol or a special liquid to dissolve the glue, which will help to more easily separate the display module and the back cover, minimizing the risk of breakage. Don't forget about safety: work in a ventilated room, so as not to inhale the vapors of heated glue and solvents.
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Use a suction cup in combination with a thin plastic mediator – this reduces the risk of splitting the glass of the back cover when opened.
Rear cover removal and primary access
The first step in the process of disassembly is to remove the tray for SIM-This action must be done at the beginning, so that when the housing is heated, the plastic tray is not damaged or blocked inside.
Turn on the hair dryer and set the temperature in the range of 80-90 degrees Celsius. Warm up the perimeter of the back cover evenly for 2-3 minutes. Don't hold the hair dryer too close to one point so as not to overheat the battery or display on the back. Periodically check the temperature with your hand - the body should be hot, but not scalding.
⚠️ Warning: Excessive heating can cause the battery to bloat or detach the polarizing film on the screen!
After warming up, stick the suction cup at the bottom of the back cover, stepping about 2 cm from the edge. Pull the suction cup up, creating a small gap, and gently insert a plastic mediator into it. Driving the mediator along the side faces, cutting the glue layer. Move slowly, without sharp jerks, so that the glass does not crack.
What to do if the lid does not open?
Disabling the plumes and removing the protective plate
After successfully removing the back cover, you will see the inside of your smartphone, immediately disconnect the battery to de-energize the board and avoid short circuits in further manipulation, and carefully bend the battery plume upwards using a plastic blade.
Next, you have to dismantle the metal shield that covers the main connectors of the motherboard, and it's mounted with multiple screws of different sizes. It's important to remember the location of each screw, because they can vary in length and threading. If you mess up the screws, you risk damaging the circuit board when you screw them in.
Use the following table to navigate the types of screws found in the Xiaomi Mi Note 3:
| Location. | Type of screw | Number of | Note |
|---|---|---|---|
| Protective fees | P2 (small) | 4 pcs. | Same length |
| Fixing dynamics | P2 (medium) | 2 pcs. | Hidden under the pad |
| Charging charges | P2 (large) | 3 pcs. | Longer than standard |
| Camera module | P2 (micro) | 1 pc. | It requires care. |
Once you've unscrewed all the screws, remove the metal plate, now the main display plume and camera plumes are available, turn them off by snapping the connectors with your nail or plastic blade, and don't use metal tools to turn off the plumes so you don't damage the contacts.
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Always turn off the battery first after opening the case - this is the golden rule of electronics repair.
Replacement of the battery and work with the glue layer
In the Xiaomi Mi Note 3, the battery is located under the top of the body and closed with additional elements. It often requires partial dismantling of the motherboard or careful bending of components. The battery is glued to bilateral tape, which eventually loses its properties or, conversely, clings to death.
Use a plastic card or a string to extract the battery, gently push the tool under the battery while making sawing movements, and it is strictly forbidden to use sharp metal objects, as a puncture of the lithium polymer battery can cause fire or a chemical reaction.
Before installing a new battery, clean the seat of the residue of old glue. Rub the surface with a soft cloth soaked in isopropyl alcohol. Apply a special adhesive layer (B-7000 or double-sided tape for phones) on the new battery to ensure reliable fixation.
☑️ Pre-assembly check
Dismantling of the display module
Replacing the screen with the Xiaomi Mi Note 3 is the most expensive and risky part of the repair. The display module here is also glued around the perimeter to the frame. The procedure is similar to removing the back cover: heating, creating a gap and cutting glue with a mediator.
But there's a caveat: the plume of the display runs under the frame and can be further fixed. Be very careful when bending the screen. If you feel resistance, check if you've forgotten to turn off any plume or unscrew the screw. A sudden movement can break the plume, and the new screen will become unworkable.
When you install a new module, make sure that the frame is cleared of glass shards and old glue. Apply a new adhesive layer around the perimeter. Press the screen evenly against the frame and fix it with rubber harnesses for 15-20 minutes to polymerize the adhesive.
⚠️ Warning: When heating the display to remove do not exceed the temperature 70-80 degrees, otherwise the matrix may get thermal damage (yellow spots).
Device assembly and final inspection
The assembly is done in reverse disassembly, first install and plug the battery, then plug the display plume in for initial inspection, without sticking the lid permanently, turn on the device and check the touchscreen, sound, cameras and proximity sensors.
If everything is working correctly, turn off the phone and proceed to the final fixation. Apply the B-7000 glue or use the pre-made adhesive frame on the back cover. Press the lid tightly against the case and remove the excess glue with a napkin.
The case is best fixed using rubber harnesses or a special press for phones. The time of complete polymerization of the adhesive is from 2 to 4 hours, but the initial grasping is faster. Do not expose the phone to loads for a day after repair.