Owners of the budget but reliable Redmi series smartphones often face a situation where the screen continues to show the image, but stops responding to touch. Unfortunately, for the Xiaomi Redmi 4X model, this problem is not uncommon and can be caused by both software failures and physical damage to the matrix. If you lose response, panic early: in most cases, the device can be brought back to life without an expensive visit to the service center.
The first thing to do when a malfunction is detected is to perform basic diagnostics to rule out accidental system freezes. Often static electricity or overheating of the processor causes a temporary failure of the digitizer. In this article, we will examine all possible causes, from simple software errors to complex hardware repairs, and give step-by-step instructions for eliminating each of them.
The main reasons for the failure of the touchscreen Redmi 4X
Problems with the touch layer (digitizer) on Xiaomi Redmi 4X are most often divided into two large groups: software and hardware. Software failures occur due to errors in the MIUI operating system, conflicts of installed applications or a failed firmware update, in which case the hardware of the device is completely functional and the problem is solved by software methods.
Hardware problems are more common, especially given the age of the 4X. Over time, the plume connecting the display to the motherboard can move away or oxidize, and the fault of the touchscreen controller itself or mechanical damage to the screen after a fall, it is important to understand that if the phone fell, the probability of physical damage to the plume or matrix is more than 80%.
Another hidden cause may be a bloated battery: In the Redmi 4X, the battery is located close to the back of the display, and when it is bloated, it starts to press the screen from the inside, creating excessive pressure on the touch layer, leading to chaotic pressing or complete sensor failure.
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If the screen started to glittle immediately after connecting the charger, most likely, the problem is in a poor-quality power supply that creates interference.
Quick diagnosis and program reset
Before disassembling the device, you need to make sure that the problem is not in the software. The easiest and most effective method is forced reboot. For this, Xiaomi usually requires pressing the power button for 10-15 seconds until the device vibrates and the Mi logo appears.
If the reboot didn't work, check the sensor in safe mode, this will eliminate the influence of third-party applications. To enter safe mode on MIUI, you need to load the phone, then press the off button in the menu and select the appropriate item, or use key combinations at start, depending on the firmware version.
It's also worth checking if the Handle function or sensitivity is enabled if you've recently changed the protective glass. Thick glass or film can shield your finger signal. Remove all protective coatings and wipe the screen with a dry soft cloth to eliminate static and moisture.
☑️ Primary diagnosis
Engineering menu and equipment testing
The MIUI shell has a powerful diagnostic tool built in to test the touchscreen performance at the hardware level, bypassing the operating system. To get into the engineering menu, open the Phone app and type in the code ##6484##. If the code doesn't work, try ##4636## or go through the settings menu.
In the CIT menu that opens, select "Touchpanel" or "TP" and you'll be asked to swipe all the grid lines. If the sensor doesn't work at all, you won't even be able to select that item, which will indicate a critical failure of the controller or the plume. If the lines are drawn, but with gaps, the problem is local damage to the digitizer.
And you can also check the other components, like vibration, display, buttons, and this can help you identify complex problems, like if you're not only not working after a fall, but you're not having sound in the speaker, and these tests are mandatory before you make a repair decision.
| Verification code | Function | The result is OK. | The result of "FAIL" |
|---|---|---|---|
| ##6484## | The full CIT test | Opening the test menu | No reaction. |
| Touchpanel Test | Sensor check. | Drawing lines | No reaction. |
| Display Test | Colour check | Change of colours | Artifacts |
| Vibrator Test | Vibrio check | Vibration. | Silence. |
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If the engineering menu does not open or the sensor test does not start, the problem is likely hardware (the plume or controller).
Touch screen calibration
Sometimes the sensor works, but it doesn't know the coordinates of the touches correctly: you click on the icon and the next one opens, or the cursor is shifted to the side, in which case calibration will help. On standard MIUI firmware, there may not be a separate calibration menu, so you'll have to use third-party utilities from the Play Market, such as Touchscreen Calibration.
The calibration process takes a couple of minutes. The app will ask you to click on dots in different corners of the screen. Once the procedure is complete, the system will recalculate the grid. It is important to perform 2-3 cycles of calibration in a row to consolidate the result.
It's worth noting that calibration only works when you program coordinates, so if you have broken glass or damaged the sensor layer, no program can restore it to work, and in such cases, you need to physically replace the module.
⚠️ Warning: After calibration, be sure to restart the device so that the new settings are saved in the system.
Hardware problems: plume and display module
If the software methods didn't work, you'll have to move to "heavy artillery." In 90% of cases, the Xiaomi Redmi 4X is to blame for the departed connector of the display plume, this is due to vibrations, falls or just old age of the glue that fixes the connection. To check, you need to remove the back cover (it is plastic and removes around the perimeter) and unscrew the screws that hold the metal frame.
When you get to the board, find the plume of the display. It's usually wide and fixed with a metal clipping bar. Carefully click the bar, remove the plume and wipe the contacts with a pin or alcohol. Put the plume back in until the characteristic click and tightly press the bar. Often after this procedure, the sensor comes to life.
If the reconnection of the plume didn't work, the touchscreen itself probably failed. In the Redmi 4X, it often comes with a matrix and a frame, but you can find individual parts. Replacing requires skills with thin electronics, since you need to unstick the broken glass and glue the new one without damaging the matrix.
Risks of self-replacement of the screen
Reset to factory settings (Hard Reset)
The last software method is a complete data reset, which will delete all your files, but will eliminate complex system conflicts. If the sensor works at least partially, you can reset through the settings menu: Settings → Advanced Settings → Restore and Reset → Reset.
If the touchscreen doesn't work at all, you'll have to use hardware buttons. Turn off your phone, then press the power button and the volume button "Up." From the Recovery menu (select by volume buttons, confirmation by power button), select Wipe Data → Wipe All Data.
Remember, after this procedure, the phone will go back out of the box, all apps, photos and contacts will be deleted, so if you have the option to connect your mouse via a USB-OTG adapter, you better save important data first.
☑️ Preparation for Hard Reset
⚠️ Warning: Before resetting, make sure you remember the password from your Mi Account and Google account. Once reset, the phone will require them to be activated, and without them, the device will turn into a brick".