Xiaomi Poco X3 has proven to be a reliable device, but even a high-quality build is not immune to mechanical damage. The upper part of the case, where the auditory speaker and the front camera are located, often suffers from falls or sloppy handling. Damage to the protective glass, which is often called a “curtain”, can lead to serious problems with the operation of the sensors and moisture protection of the body. If you notice cracks on the upper end or the proximity sensor stops working during a conversation, then the replacement of this element becomes inevitable.
Restoring the integrity of the upper body is a procedure that requires accuracy and understanding of the device of the smartphone. Unlike simple replacement of the display glass, you need to work with the plume of the proximity sensor, which is often integrated into the design of the module. Incorrect actions can cause the screen to go out during a conversation or stop responding to the application to the ear. In this article, we will discuss in detail the process of diagnosis, selection of components and step-by-step replacement of the curtain on your device.
Before you start, you need to assess the extent of the damage. Sometimes you need to replace only the external decorative glass, but in most cases, especially when impacted, the plastic frame or the speaker suffers. It is important to understand that for a smartphone to work properly, it is better to change the module assembly to keep all the sensors tight and working correctly. Next, we will look at all the nuances of this process.
Diagnostics of faults of the upper module
Before you start disassembling the Poco X3 NFC or Pro, you need to determine exactly the nature of the malfunction. Often users confuse the software failure of the sensor with the physical damage to the curtain. If there are no visible cracks on the protective glass, but the proximity sensor is not working correctly, it may be the contamination or displacement of the plume. However, if there are chips or cracks on the upper end, the risk of moisture and dust entering the body increases many times.
Special attention should be paid to the work of the auditory speaker. If the sound has become quiet, hoarse or gone completely, this is a direct indicator of membrane damage or contact loss. It is also worth checking the front camera: if blurry spots or artifacts appear in photos, the optical axis or protective glass of the camera, which is part of the general curtain, may damage, ignoring these symptoms can lead to the failure of more expensive components.
- 🔍 Check for visible cracks on the upper end of the body in bright light.
- 📞 Make a test call and hold your hand to the top of the screen to check the screen quenching.
- 🔊 Listen to the test sound through the auditory speaker at maximum volume.
- 📸 Take a few pictures on the front camera to check the quality of the optics.
You can use the MIUI engineering menu to make a precise diagnosis, and by entering a special code in the Phone app, you can access the tests of all the hardware components, which will help you eliminate software errors and make sure that you really need to change the curtain, and if the tests show an error in the proximity sensor when the whole curtain is in place, you may need to reconnect the plume or replace it separately.
Required tools and materials
To replace the curtain on the Xiaomi Poco X3, you will not only need a new module, but also specialized tools to work with small electronics. Using inappropriate items such as knives or thick screwdrivers can damage the plastic latches of the case or even damage the battery.
The main tool will be a set of precision screwdrivers, including cross bits sizes PH00 and PH000, also must have plastic blades (mediators) to open the body without scratches and metal thin scalpel or blade to cut old glue. Don't forget to prepare a sucker for the careful lifting of the back cover and tweezers to work with small plumes.
☑️ Checking readiness for repair
As consumables, be sure to use a special glue B-7000 or high-quality double-sided tape for electronics. Normal superglue is strictly forbidden to use, since its vapors can settle on cameras and sensors, making them inoperable.
The process of disassembling the Poco X3 smartphone
Poco's disassembly X3 Starts by turning off the device and removing the tray SIM-This is a critical step, because trying to remove the back cover with the SIM card installed can damage the contacts or the tray itself, and then you need to warm the perimeter of the back cover with a hairdryer or on the heating platform to a temperature near the temperature of the back cover. 80-90 degrees Celsius to soften factory glue.
Put a suction cup on the bottom of the back cover, pull it back, and insert a plastic blade into the gap, carefully use the tool along the perimeter of the case, trying not to touch the internal components, exercise special care in the main camera module and fingerprint scanner, where the plumes are located, after peeling off the lid, put it in a safe place.
Careful with the fingerprint scanner plume!
The next step is to dismantle the plastic shield that covers the insides of your smartphone, and it attaches to a lot of screws around the perimeter and in the center, and after you twist all the screws, gently slap the panel with a spatula and remove it, and you now have access to the battery and the plumes, but you have to move on to replace the curtain, removing the motherboard.
Replacement of curtain module and dynamics
The upper part of the case, where the curtain is located, is only opened after the motherboard is removed, which is a complex operation that requires turning off many plumes, first of all, turn off the display plumes, touch screen and battery, and only after de-energizing, you can unscrew the screws that lock the board and remove it from the case.
At the top of the case, you'll see a hearing aid module that's often assembled with a proximity sensor and a front camera, and that's the assembly that needs to be replaced. Carefully unplug the speaker plume from the motherboard (if it's still connected) and remove the old module from the seat, clear the niche of dust and glue residue before installing the new part.
| Component | Function | Risk of replacement | Difficulty |
|---|---|---|---|
| Protective glass (curtain) | Sensor protection and dynamics | Damage to the plume | Medium |
| Auditory speaker | Sound reproduction | Contact break | Low. |
| Approximation sensor | Screen-closing when you call | Wrong job. | Tall. |
| Front camera. | Filming and unlocking | Damage to the matrix | Tall. |
Put the new module into the seat, making sure it sits tightly and doesn't hang around. Connect the plume to the corresponding connector on the motherboard. When you build it, it's important not to confuse the direction of the connection, because this can lead to short circuits. Once you install it, you can start to reverse assemble the device, following the order of the operation in the opposite direction.
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Replacing the curtain with the Poco X3 is impossible without removing the motherboard, as the speaker and sensor module is underneath it.
Assembly and seal check
After a successful replacement, all surfaces must be thoroughly cleaned of old glue and degreased. Apply a thin layer of B-7000 glue to the body frame or use a pre-prepared double-sided tape. Set the plastic safety panel in place, fasten all screws and check the reliability of the fixation. Make sure that no plume has been pinched.
Then, install the motherboard, plug in all the display, touchscreen and battery plumes. It's recommended that you do a first check before you close the case. Turn on your smartphone and check the sound, the proximity sensor and the front camera. If everything works correctly, you can stick the back cover.
⚠️ Warning: Don't put too much glue on assembly. Excess glue can squeeze out or, worse, leak into the housing, damaging connectors or speakers. Use the minimum amount of adhesive required.
For final fixation, press the back cover with rubber harnesses or put something heavy (but not too heavy to not damage the display) on your smartphone for 1-2 hours. This will ensure a reliable grip of the glue and restore the tightness of the body. After drying the glue, wipe the body from the residues of the adhesive with alcohol.
Calibration of the proximity sensor
Once the curtain and proximity sensor are replaced, software calibration is often required, and even a new, serviceable sensor can malfunction without sensitivity settings. There is a special section for calibration in the MIUI engineering menu. Go to the testing menu, select "Proximity sensor" and follow the instructions on the screen.
Normally, the calibration process involves closing the top of the screen with your palm and then opening it, and the system will determine the minimum and maximum light values. If the automatic calibration doesn't help, you can try resetting the sensor through special commands in the engineering menu or calibration apps from Google Play.
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If the sensor still blows out spontaneously after being replaced and calibrated, try sticking a thin layer of thin tape on the sensor itself (located next to the speaker), which sometimes helps reduce the sensitivity of sensors that are too powerful.
In some cases, especially when installing non-original parts, the standard calibration may not work, then it is worth checking for updates to the MIUI firmware, since new versions of the software often fix hardware errors, and if this did not help, you may need to replace the sensor plume itself or solder the contacts.
Typical errors and their solution
One of the most common mistakes when replacing a curtain is to damage the plume when it is not neatly disassembled. The thin tracks of the plume are very easy to tear with a sharp tool. If after assembly the smartphone stopped seeing the SIM card or lost sound, the corresponding plume was most likely damaged, in which case the entire plume will need to be replaced.
Another common problem is getting glue onto the speaker grid, which causes the sound to become deaf or quiet. If this happens, carefully remove the excess glue with a toothpick, trying not to prick the mesh. It is also important to keep the speaker clean before installation, as dust can worsen the sound quality.
⚠️ Attention: Never try to bend the plume at a sharp angle. The plumes in modern smartphones are very fragile and lose conductivity when the rims are broken. All bends must be smooth and consistent with the factory design.
If you find that the front camera is taking murky pictures after you've been replaced, check to see if there's a protective film left on the inside of the new curtain glass. Often, parts manufacturers leave a film that needs to be removed before final assembly. Also make sure the camera lens is clean and has no fingerprints on it.