Disassembling the flagship Xiaomi Mi 9 is a process that requires not only accuracy but also a deep understanding of the internal architecture of the device. The company's engineers used glass body design, which makes the dismantling procedure more difficult than metal counterparts. Any careless movement can damage fragile elements, so preparing the workplace is critical.
The challenge is that the back cover is glued all around the perimeter, and the screws are hidden under the decorative elements. Unlike older models, there are no comfortable screws on the sides of the frame. You will need a specialized tool and patience to avoid damaging the plumes running along the body.
Before you start physical impact, you need to completely discharge the battery or, conversely, charge the device to 20-30% to avoid ignition when the battery is damaged during operation. However, the golden rule of repair says that it is better to work with a battery with a charge of about 25-40%, since a fully discharged lithium polymer can be unstable, and a fully charged one is too dangerous when punctured.
⚠️ Warning: Before any work begins, be sure to turn off the device. Attempting to disconnect the connectors under voltage can lead to a short circuit and failure of the power controller.
In this article, we will take a detailed look at each step, from heating the edges to final assembly.The Xiaomi Mi 9 has a tight layout, so each step must be done sequentially.
Tools and workplace preparation required
High-quality disassembly of the smartphone is impossible without the right tools. The use of improvised tools such as knives or pins is strongly discouraged, as they can damage the internal components or leave scratches on the frame. You will need a set of precision screwdrivers, since the screws in Xiaomi have a specific head.
Pay special attention to the heat source. To soften the glue under the back cover, you need a hair dryer or a professional heating pad. Household hair dryers often do not give enough temperature or, conversely, overheat the local area, which is dangerous for the hair. OLED-The optimum temperature of heating is 80-90 degrees Celsius.
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Use a thermometer or thermal imaging device to monitor the heating temperature of the back cover. Exceeding 100 degrees can damage the adhesive layer irrevocably or deform plastic frame elements.
Also prepare plastic mediators and a suction cup. Metal blades are best avoided in the initial stages, so as not to damage the glass panel. The workplace should be well lit and free of metal objects that may accidentally fall inside the case.
- 🛠️ Set of screwdrivers (cross-crosses) PH000, PH00 Torx T2, T3)
- 🔥 Hair dryer with temperature adjustment or heating platform
- 💳 Plastic cards, mediators and sucker
- 🧲 Magnetic screw-sorting mat
- 🧴 Isopropyl alcohol or special solvent of glue (B-7000)
Besides the main tool, be sure to have tweezers with curved ends, which will be needed for gently tweezing the plumes and extracting small details from the depth of the case, and an anti-slip mat will also be a great addition to prevent the device from slipping while working.
Removal of the back cover and access to screws
The first step is to dismantle the back panel. Turn on the hair dryer and warm up the perimeter of the device evenly for 2-3 minutes. Do not keep the hot air flow at one point longer than 5-10 seconds to avoid local overheating of the display matrix on the back side.
After warming up, press the suction cup at the bottom of the back cover, just above the Mi logo. Pull up, creating tension, and in the resulting gap carefully insert a plastic mediator. Drive the tool along the faces, gradually cutting through the adhesive layer.
⚠️ Attention: At the top of the smartphone, in the camera module area, the adhesive layer may be thicker and the structure more fragile.
When the lid is removed, don't try to remove it completely at once. It's connected to the motherboard in a thin plume that can be easily ripped in a sharp jerk, put the phone on the table with the back cover upwards and bend it like a page of a book, gaining access to the insides.
Nuances of the glue layer
Now you have access to a protective plate that hides the main fasteners, and in this model, the screws are not only located along the perimeter, but also in the central part, which requires careful twisting.
Dismantling the protective plate and disconnecting the plumes
Under the back cover is a metal plate covering the connectors of the battery, the display and the main modules, and it's secured by multiple screws of different sizes, and it's critical to remember or record the location of each screw on the magnetic mat, because they have different lengths and threads.
Use a screwdriver of the right size to keep the screw caps from licking. After you unscrew all the fasteners, carefully remove the plate, and underneath it, you'll see the main plume connecting the display to the board, and the battery connector.
The first thing you need to do is turn off the battery, and it's a safety requirement before any further manipulation, and you can use a plastic shoulder blade or a gloved finger to snap the connector off, and you can't use metal tweezers to avoid circuits on the board.
- 🔋 Turn off the battery connector first
- 📱 Disconnect the display plume and touchscreen
- 📷 Turn off the main camera plume
- 🔌 Remove the lower board connector (USB)
Once you've turned off all the visible plumes, you can take the entire plate off, and notice that it might have a side button plume or antenna contacts glued to it, and you can go slowly, and make sure there are no hidden connections left.
☑️ Safe shutdown
Now the motherboard and other components have no active connections to the power source, which allows you to safely carry out further disassembly of the case without the risk of short circuit.
Removal of the battery and lower board
In the Xiaomi Mi 9, the battery occupies a significant part of the interior space and is fixed to two strips of glue. To extract it, you will need to apply heating again, but on the front side if you do not remove the display, or directly through the access, using caution.
The best way to remove the battery is to use special hoods with suction cups or a plastic card dipped in isopropyl alcohol. Soak the adhesive strips with alcohol through the gaps, wait a couple of minutes and carefully deflate the battery, trying not to deform it.
⚠️ Warning: Never use metal tools to tamper with the battery.Puncture of a lithium polymer battery causes instant ignition and release of toxic substances.
Once the battery is removed, you can access the bottom of the case, where the charger board and the speaker are, and the board is secured by screws and connected by several plumes that we've already disabled in the previous step, and carefully remove it by pulling the textolite part.
The speaker in this model is glued to the frame, and it will also require careful warming and squeezing to replace it, and be careful with the contact platform, which is pressed by screws to the main board through spring contacts or a plume.
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The battery in Xiaomi Mi 9 has a high profile. When installing a new battery, make sure the connector is up exactly the first time so as not to damage the contacts on the board.
Freeing the space from the battery and lower modules allows access to the screws that fasten the motherboard and the plumes that pass under it.
Removal of the display and motherboard
The riskiest stage is the dismantling OLED-In the Xiaomi Mi 9, the screen is glued around the perimeter to the frame. If your goal is to replace the screen, then the previous steps could be skipped, starting immediately with heating and removing the cover, and then the display.
To remove the display, you need to warm up the front of the phone. Use the suction cup and the mediators as you move around the perimeter. There are plumes under the screen, so you should avoid deep immersion of the tool. Once the screen is separated from the frame, disconnect it from the board if you haven't done this before.
The motherboard is secured by several screws around the perimeter and one in the center, and it's also held by plumes passing through the holes in the frame, gently raise the board, check if all the plumes are off, and remove it from the case.
| Component | Firming | Features of withdrawal |
|---|---|---|
| Back cover. | Clay. | Requires heating to 80-90°C |
| Protective plate. | Screws (different) | It's important not to mix up the screws. |
| Battery | Sticky stripes. | Dangerous to deform, you need alcohol |
| Maternity fee | Screws + plumes | Requires complete shutdown of all modules |
When removing the motherboard, pay attention to the location of the antenna contacts and the vibrator motor. Often the vibrator motor is simply inserted into the seat and can fall out when you move sloppy, and also check if the power button plume is stuck to the frame.
After removing all the major components, you have an empty frame that can be cleaned of glue residues and contaminants, which completes the stage of completely disassembling the device.
Assembly of the device and verification of functionality
The assembly is done in reverse order, but requires even more care. Start by placing the motherboard in the frame. Make sure it's flat, smooth, and all the screws are twisted easily. If the screw doesn't go, don't push -- maybe the board got wrong.
Next, install the battery. Before gluing the new battery, be sure to check its voltage with a multimeter. It should be within 3.7-3.8 V. Stick the battery to special adhesive strips or double-sided tape, ensuring a tight fit throughout the area for better heat sink.
Put all the plumes in the right sequence: first the battery, then the display, the cameras, and the bottom board, and set the safety plate and twist all the screws, and see if there are any extra parts left.
- ✅ Set a charge and spin the screws
- ✅ Stick and plug the battery in.
- ✅ Connect the display plumes and cameras
- ✅ Set up a protective plate.
- ✅ Stick the back cover.
The final step is to glue the back cover, apply a thin layer of B-7000 glue, or use a pre-made glue circuit, press the lid and lock the device with rubber bands for 15-20 minutes before the initial glue grasp.
Once assembled, turn on the device and check all the modules: sensor, cameras, microphones, speakers and charging. If everything works correctly, the process can be considered successful.