Smartphone Xiaomi Mi 9 SE deservedly gained a reputation as one of the most successful compact flagships of its time, but even a reliable device is not immune to mechanical damage. Broken glass or the appearance of stripes on the matrix is not just an aesthetic defect, but a direct threat to the functionality of the gadget, since the touchscreen can stop responding to touch at any time. Self-replacement of the display requires accuracy, understanding of the design and the presence of a specialized tool, but allows you to save a budget compared to contacting the service center.
Before you start disassembling, you need to realize that the design of modern smartphones involves the use of a large number of adhesives for moisture protection and fixing components. The repair process of the Mi 9 SE is complicated by the fact that the screen is not only fixed along the perimeter, but also has additional fixation points, and the module itself is integral (AMOLED matrix is soldered with a touchscreen).
In this article, we will go into detail about workplace preparation, the tools you need, and the step-by-step algorithm for a successful installation of a new module. You don't need to be a professional engineer to handle this task, but focus and lack of rush are critical to success. If you're willing to work hard, then restoring your smartphone is quite feasible at home.
Tools and workplace preparation required
Quality repairs start with the right organization of space. You'll need a table with good lighting, preferably daylight or under a bright lamp, to see small screws and connectors. The surface should be clean, flat and, very importantly, not conduct static electricity that can kill the electronics of a smartphone. An antistatic mat is ideal, but you can use a regular wooden countertop, covered with clean cloth.
To replace the display with the Xiaomi Mi 9 SE, you will need a specific set of tools that are not always in a standard home medicine cabinet. The absence of even one suction cup or screwdriver can turn a simple process into anguish or lead to a breakdown of the body. Prepare everything you need in advance so as not to be distracted at the most critical moment.
- 🔧 A set of precision screwdrivers (mandatory presence of cross-shaped) P2 and P0, and flat for the squirrel-crushing).
- 🔥 Dryer or heat pad (to soften the glue under the screen, the heating temperature is about 80-90 degree).
- 💳 Plastic cards or mediators (used to carefully separate the display from the frame without scratching).
- 🧪 Clay. B-7000 or T-8000 (for final sealing of the body after replacement).
- 🧲 Magnetic mat or organizer for screws (so as not to confuse fasteners of different lengths).
Pay special attention to the state of the battery before work. If the battery is swelled or damaged, it should be replaced first, since heating with a hairdryer during disassembly can provoke fire. Safety is the number one priority in any interference with the design of an electronic device.
Dismantling of the back cover and internal components
The process of dismantling Xiaomi Mi 9 SE starts from the back of the device, as access to the main nodes opens from there. the back is glass and planted on glue, so its removal requires patience and preheating. Do not try to pull the lid with metal objects immediately - this is guaranteed to lead to chipped or cracked glass.
⚠️ Warning: Heat the back cover evenly throughout the perimeter during 3-5 Do not hold the hair dryer in one point for too long, so as not to damage the display matrix on the back side or overheat the battery.
Once the glue has softened, gently insert the suction cup at the bottom of the back cover, just above the Mi logo, and pull slightly to create a gap. Insert a plastic card or mediator into the resulting gap and lead it along the faces, gradually peeling off the lid. Move slowly, feeling the resistance of the glue, and add heating if necessary.
When the lid is removed, you'll see a protective plate covering the main board and the battery, it's also attached to the screws and glue. Unscrew all the visible screws (usually about 10-12 pieces), remembering their location, because they can be of different lengths. Once the protection is removed, you'll have access to the battery and plumes.
The next critical step is to turn off the power, find the battery connector on the board and gently disconnect it with a plastic blade, only then you can touch the other connectors, turn off the main and front camera plumes, and the display plume, if available, although most often the screen is removed along with the frame.
☑️ Checking before disassembly
Removal of the display module
Unlike many other models, the Xiaomi Mi 9 SE display module is often assembled with a frame, which makes it easier to replace, but requires repositioning some elements. If you bought a module without a frame, the process will be much more complicated and will require re-painting the matrix, which is not recommended at home due to the risk of damage to the fragile AMOLED screen.
To remove the module, you need to completely free it from the mounts. Check the perimeter of the device for hidden screws under stickers or rubber plugs. Carefully disconnect all the plumes that go from the board to the screen (main plume, touchscreen plume, sensor plume).
- 📱 Turn off the main speaker plume if it interferes with access to the screen mounts.
- 🔌 Carefully move the fingerprint scanner plume aside (if it is integrated into the screen or located next to it).
- 🧩 Remove the control board (motherboard) if your revision design requires it to access the bottom of the screen.
Now that all the connections are broken, you can start to separate the screen. Heat the front of the smartphone with a hairdryer around the perimeter to soften the glue that holds the display frame. Use a suction cup and mediators to separate the module from the body in a circle. Act carefully, do not press on the center of the screen so as not to push the matrix.
After removing the old module, thoroughly clean the case of the smartphone from the residues of old glue. The surface must be perfectly smooth and fat-free, otherwise the new screen will lie uneven or you will see the lights. Use isopropyl alcohol and a lilac-free napkin for the final cleaning.
Installation of a new module and assembly
Before installing a new display on the Xiaomi Mi 9 SE, you need to transfer some elements from the old module if you purchased a version without a bezel or without some components. Most often you need to rearrange the earpiece with a mesh, proximity sensor and sometimes plumes if they do not come with a complete set.
Apply a thin layer of special glue (B-7000 or analog) to the end of a new frame or smartphone body. Don't overdo it with the amount of glue, its excess can protrude outside or get inside the case, damaging the electronics. Let the glue dry a little (1-2 minutes) to make it sticky.
Carefully install the new module in the case, combining all the holes and protrusions. Press the screen evenly around the perimeter, ensuring a tight fit. Immediately connect the display and touch screen plumes to the motherboard, but do not fix them with metal clipplates.
Turn on your smartphone without putting the lid on to check the new sensor and touchscreen. Make sure there are no broken pixels, color reproduction is correct, and the multi-touch works throughout the area. If all is well, turn off the device and continue building.
What to do if the screen is not turned on?
Testing and calibration of the touch screen
After the physical installation and initial activation, careful testing is required. The AMOLED screens used in the Mi 9 SE are sensitive to signal quality, so it is important to make sure there are no dead zones.
To get into the test menu, open the Phone app and enter the code ##6484##. From the CIT menu that opens, select "Touchpanel" or "Display." Follow the instructions on the screen: draw lines, check for multiple touch responses.
| Verification parameter | Normal condition | Signs of malfunction |
|---|---|---|
| Touch response | Instant, no delays | Delay, misses touches |
| Multitouch | Support for 10 points simultaneously | Fewer than 5 points are triggered. |
| Color rendering | Uniform, spotless. | Pink/green shades, spots |
| Brightness | Smooth adjustment | Blinking, lack of autobrightness |
If the tests are successful, you can start the final assembly: screw the protective plates of the plumes, connect the battery and glue the back cover, install the smartphone under the press or put a heavy book on it for 1-2 hours to polymerize the glue.
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After changing the screen, it is recommended to calibrate the proximity sensor. In the same engineering menu (CIT), select "Proximity Sensor", tape the top of the screen and check if the value changes from 5.0 to 0.0.
Possible problems and solutions
Even with all the instructions, there can be unexpected situations, and users often find that after assembly, the smartphone behaves strangely: it discharges quickly, warms up or does not see. SIM-This may be due to loose fitting of connectors or damage to plumes during operation.
One common problem is the lack of touchscreen response in certain areas, which can be caused by factory defects of the new module or contamination of contacts during assembly, and software freeze of the power controller, which is solved by a complete reset to the factory settings (Hard Reset).
- 🔋 Fast discharge: Check if you damaged the battery plume or charge controller when disassembling.
- 📶 Bad signal: Make sure the antenna contacts (usually the gold patches on the board and body) are clean and tightly pressed.
- 🔊 No sound: Check the connection of the plume of the lower speaker and the conversational speaker.
If you notice that the screen is peeling off at the edges or bubbles appear, then the glue layer was unevenly applied or the surface was poorly cleaned, in which case you may need to re-disassemble and apply a new layer of adhesive.
⚠️ Warning: If the smartphone stopped charging after changing the screen or shows the wrong percentage of charge, immediately disassemble the device.
Frequently Asked Questions (FAQ)
Can you replace the glass with the old matrix?
How much does the glue dry after changing the screen?
Will the warranty disappear after self-replacement?
Why can a new screen have a different color?
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The main secret of a successful replacement is not to rush with heating the glue and always turn off the battery before working with the plumes.