The process of dismantling the Xiaomi Mi 9 requires increased accuracy and understanding of the design of a modern smartphone. This flagship 2019 is equipped with a glass back panel that is attached to a durable adhesive composition, which significantly complicates access to internal components compared to devices with removable covers. The main difficulty is that if you unwary opening, you are at high risk of damaging the rear window or bend the plumes connecting the motherboard to the periphery.
Before any manipulations, you need to prepare a workplace with good lighting and an antistatic mat, if possible. You will need a set of precision screwdrivers, plastic blades, a suction cup and, preferably, a thermophen or heating pad for softening the adhesive. The glue under the back cover of the Xiaomi Mi 9 softens at a temperature of about 80-90 degrees Celsius, but it is dangerous to heat the glass longer than 2-3 minutes due to the risk of damage to the oleophobic coating or the display on the back side.
It’s important to understand that disassembling the Xiaomi Mi 9 is not modular in the traditional sense of old phones. You can’t just remove the lid and remove the battery; access to most nodes is blocked by metal screens and tightly stacked plumes, so each step must be done methodically, without sudden movements and the use of excessive force that can lead to cracks in the components.
There are several reasons why owners decide to intervene in the design of the gadget, most often it is a failure of the battery, a broken rear window or the need to replace the bottom plume with a microphone.
- 🔋 Replace a worn-out battery that stopped holding charge during a working day.
- 📱 Restoring the integrity of the back panel after a fall or mechanical impact.
- 🔌 Repair or replacement of the lower charger connector (USB-C) and the main microphone.
- 🧹 Deep cleaning of the speaker and internal cavities from dust and pile.
It is worth noting that self-disassembly automatically deprives the device of an official warranty if it was still in force at the time of treatment, but for devices released several years ago, this factor often goes by the wayside before the need to extend the life of your favorite gadget.
Before you start physically affecting the case, you need to do a series of preparatory steps that will secure your data and simplify the process. The first thing you need to do is turn off your smartphone completely, not just put it into sleep mode, but perform a complete shutdown procedure through the menu or hold the power button.
⚠️ Warning: Before starting the disassembly, be sure to remove the tray SIM-If you forget to do this, if you try to tamper with the body or warm up the end, you can damage the tray mechanism or the motherboard itself in the contact area.
Then you have to remove the screen's protective glass if it's glued, so that when the body is heated, the glue under the protective film doesn't melt and leave hard-to-remove traces, and also to avoid film displacement, and if there's a case on the device, it also needs to be removed and inspect the ends for residual glue.
You will need a specific set of tools to work, which is different from the standard PC suite. Lack of the right tool often leads to the breaking of the screw faces or damage to plastic latches. It is recommended to use only high-quality metal blades and suction cups, as cheap plastic can break inside the case.
- 🔥 Thermophen or heating pad for heating the adhesive layer around the perimeter.
- 🛠 Phillips screwdrivers set (cross) sizes #00 and #000.
- 🧲 Magnetic mat or organizer for sorting screws of different sizes.
- 🧤 Tweezers with curved ends for careful extraction of plumes.
The workspace is specially designed. The screws in the Xiaomi Mi 9 are of different lengths and threads, and if you mix them up in places when you build them, you can punch through the motherboard or damage the threads in the landing holes, making further operation impossible.
Heating the case is a critical step in the success of the entire operation. The Xiaomi Mi 9's rear window is glued all around the perimeter, and the glue is quite viscous. Insufficient heating will cause the glass to crack when it tries to detach, and excessive can damage the display, as heat is quickly transferred through a thin layer of metal and plastic.
The heating process is best done using a heating pad, setting it at a temperature of about 80 degrees, or a hairdryer, constantly leading a stream of air around the perimeter, without lingering long at one point. The heating time is usually 3-5 minutes, after which you need to check the softness of the glue, carefully trying to enter the shoulder blade into the corner.
After enough warming up, a suction cup and a thin metal or plastic spatula come in, and we hold the suction cup at the bottom of the back cover, we pull it slightly back, we create tension, and we carefully insert the blade into the micro gap, and the movements must be sliding, parallel to the plane of the smartphone.
⚠️ Attention: It is strictly forbidden to insert the blade deep inside the case immediately after opening the gap.In the upper part of the smartphone, under the glass, there are plumes of cameras and display that can be easily cut or damaged by the sharp edge of the tool.
As you move around the perimeter, you need to periodically reheat the areas where the blade is difficult to move, pay special attention to the corners, because the adhesive layer is often thicker, and don't try to crack the glass with one jerk, which is a guaranteed way to get cracks.
When the blade passes around the perimeter, the back cover should be easy to detach, but don't be too quick to put it away. In some versions, the fingerprint scanner can be integrated into the plume that runs from the main board, although it is built into the display in the Mi 9, but it is easy to confuse the models.
When you take the back glass panel off, you see the inside of the smartphone, protected by a massive black plastic cover, which has several functions: it presses the battery, protects the components from dust, and acts as a heat sink, and it attaches itself to a lot of screws around the perimeter and in the center.
The first thing you need to do is to unscrew all the visible screws that are fixing this protective pad. 10-12 It's recommended that you put it on the circuit or in the box with the signature from which it was taken, as soon as you unscrew each screw.
☑️ Check before charge is withdrawn
Once the screws are removed, the plastic lining will not be removed immediately, because it is hooked by plumes, and at the bottom there is the main charging plume, and at the top there are connectors going to the motherboard, and carefully lifting the bottom of the lining, you can access the battery connector.
The most important rule when working with electronics is to turn off the device first, find the battery connector on the motherboard (usually under or near the top of the plastic cover) and gently disconnect it with a plastic blade, only after that you can continue disassembling.
Now you can take the plastic cover off completely, and underneath it you'll see the main motherboard, the metal screen, the main camera module, the vibrator, and other components, and the metal screen is soldered or glued, and it's not recommended to open it without the extreme need (for example, repairing the board itself).
Then you have to disconnect all the plumes that go to the motherboard, which are the display plume, the lower board plume (charging), the camera plumes and the antenna contacts, and the antenna contacts (golden springs) must be bent very carefully so as not to break their base.
| Component | Location. | Type of attachment | Features |
|---|---|---|---|
| Battery | Central part | Adhesive tape + pressing bar | Requires careful unhooking |
| Maternity fee | Top third. | Screws + plumes | Lots of small connectors |
| Charging charges | The bottom part | Screws + plume | Integrated microphone |
| Main camera. | Center-top. | Enters the groove + plume | Fragile optics, do not touch your fingers |
Removing the battery is one of the most common causes of disassembly. In the Xiaomi Mi 9, it is planted on a rather sticky glue. To extract it, it is recommended to use special hoods with suction cups or gently tweak with a plastic card, preheating the battery area with a hairdryer (very carefully!).
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Use isopropyl alcohol (90%+) to dissolve the glue under the battery. Enter a little liquid around the battery perimeter and wait 2-3 minutes before extraction.
When installing a new battery, make sure you use the original adhesive base or apply a new double-sided scotch. The battery dangling inside the case is a direct road to damage to plumes and short circuit.
The Xiaomi Mi 9 is built in a strictly reverse order, but with some nuances. The main thing is to remember to connect all the plumes before installing the pressurized plastic and metal slats. Make sure that all the connectors are snapped to the characteristic clicks.
Before the final sticking of the back cover, it is recommended to temporarily turn on the device, check the touchscreen, sound, microphone, cameras and charging. If everything is functioning correctly, you can apply a new glue (B-7000 or special adhesive tapes) and press the rear panel.
⚠️ Attention: When applying glue B-7000 Avoid getting the compound inside the connectors, speakers and microphones. Excess glue that has protruded outside must be removed immediately before they freeze, otherwise there will be ugly marks on the glass.
Fixing the back cover is best done with money bands or special clips, leaving the smartphone to dry for 2-4 hours, which will ensure uniform fit and reliable sealing of the case.
What if the phone doesn’t turn on after assembly?
When repairs are done, there is a lot of water resistance, and even with a new factory sticker, it's almost impossible to restore IP68 at home, and the glue can provide splash protection, but not water immersion.
Treat plumes with extreme caution. They're very thin and easily torn when you pull them, and if you feel resistance when you pull something off, you've forgotten to unscrew some screw or disconnect another plume.
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Quality workplace preparation and the right tool is 90% of the success when disassembling Xiaomi Mi 9. Don’t skimp on tools to avoid damaging expensive components.
The result of the proper disassembly and assembly will be a functional smartphone that will last for a long time, the main thing in this process is patience and attention to detail, because modern gadgets do not forgive rushes.