Xiaomi Redmi sensor doesn’t work: a complete repair guide

When the sensor on Xiaomi’s smartphone suddenly stops working, it can knock out anyone, the screen burns, the image is there, but the device stops responding to touch, turning into a useless piece of plastic and glass. Most often, the problem lies not in a fatal breakdown, but in a software failure or temporary overload of the system, which can be fixed without visiting the service center.

Owners of Redmi Note and Xiaomi Mi models often face so-called “dead zones” or complete touchscreen failure after a firmware update or drop. It is important not to panic and consistently check the software and hardware causes of the malfunction, as diagnostic methods are radically different. In this article, we will analyze all possible scenarios, from simple reboots to complex hardware tests.

If your phone ignores the presses completely, the first thing you should do is try a forced reboot, press the Power button and hold it for 10-15 seconds until the device vibrates, which helps to reset the static electricity that often causes the digitizer to "glitch."

The main reasons for the refusal of touchscreen Xiaomi

Understanding the nature of a fault is half the success of fixing it. Sensor problems fall into two big groups: software and hardware. Software failures arise from conflicts in the MIUI operating system, driver errors or cache overflows, in which cases the touchscreen may work unstablely, phantomize or shut down in certain applications.

Hardware causes are more serious and often require intervention in the "iron" These include mechanical damage to the screen after falls, moisture entering the body or detachment of the plume, and the influence of external factors, such as poor-quality protective glasses or cheap chargers, which create interference.

⚠️ Note: If the sensor failure occurred immediately after the phone hit the water, in no case try to charge the device or connect it to the PC. moisture could cause a short circuit in the power controller, and the current supply will finally beat the fee.

Often, users don't notice that the problem lies in the banal overheating of the processor. When you put intense load, the temperature inside the case rises, and the capacitive layer of the screen may temporarily lose sensitivity. Let the gadget cool down when it's off, and maybe the sensor will start to respond again.

Quick ways of resuscitation without disassembly

Before you carry a device for repair or disassemble it, try a number of software methods that often help restore functionality. The first and most effective way is to clean up memory and cache. A crowded operational buffer can cause interface lags that are mistakenly perceived as sensor failure.

The second method is to use the engineering menu to check the hardware, and even if the sensor is partially working, type ##64663## in the dialing field, and that will open the testing menu where you can select "Touchpanel" and do the diagnostics, and if the sensor works perfectly on that menu, it's a problem with the software or third-party applications.

The third option is relevant if the sensor is "dull" or running with a delay. Try changing the frequency of the sensor survey in the developer settings, if such an option is available in your version of MIUI. Sometimes the standard 60 Hz or 120 Hz conflict with the current state of the drivers, and the frequency reduction can temporarily regain control of the device.

Diagnostics through the Engineering Menu and ADB

For a deeper diagnosis, when the touchscreen is working but intermittently, you can use a computer and debug over USB. This method requires pre-activation of the developer mode. If the sensor is not working completely, this step will have to be skipped, but if it is partially reacted, it is extremely effective for detecting dead zones.

Connect your smartphone to your PC through USB-You can use the cable and you can type in the command line to check the status of the touch drivers, and you can see if the controller is recording your touches at the system level, and if the system sees the touches, but the interface doesn't respond, then the problem is the Android shell or launcher.

adb shell getevent -l

This command will output the event stream from all input devices. Touch the screen and see if the coordinates appear. If you touch a certain area of the screen, you don't see any lines, you have physical damage to the digitizer in that area.

Hardware problems: plumes and display

If the software didn't work, it was probably hardware. The most common reason for a sudden sensor failure on Xiaomi was the drop of the connector of the display plume, which often happens after a fall, even if there is no external damage, and the vibration on impact could simply weaken the contact.

Another common problem is the failure of the digitizer itself (the touch layer), which is often glued to the matrix in modern smartphones, so replacing the module requires a complete replacement, and you can determine the breakdown of the digitizer by the characteristic cracks under the glass or the appearance of purple spots that creep around the screen.

To check the plume, you will need to carefully open the back cover (if it is glass, you need a hairdryer) or remove the frame. It is critical to turn off the battery before any touch of the display plumes! Connecting the plume under voltage is guaranteed to disable the power controller or the screen itself.

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When disassembling Xiaomi, use a suction cup and a mediator. Do not try to lid the knife - there is a high risk of damage to the plume of the fingerprint scanner or the rear window.

Resetting settings and flashing the device

If you're sure that the hardware is intact, but the sensor isn't behaving properly, a full Hard Reset will help, which will remove all data from the phone, returning it to factory status. Often conflicting applications or modified system files will block the input drivers from working correctly.

To reset without access to the menu, use a button combination. Turn off the phone, then press Volume Up and Power. From the Recovery menu, select Wipe Data. If the sensor doesn't work even in Recovery, it's almost a 100% guarantee of hardware failure.

In difficult cases, it helps to flash through a computer using the Mi Flash Tool, which will overwrite all system partitions, including those responsible for calibrating the touchscreen, but if the problem is physical, the firmware will only confirm the diagnosis, but will not correct it.

⚠️ Warning: After resetting or flashing all your photos, contacts and apps will be deleted. Be sure to back up important data if the sensor allows you to do this at least partially (for example, through the cloud or mouse connection).

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If Hard Reset and flashing have not solved the sensor problem, further software manipulation is useless – a touchscreen or plume replacement is required.

Sensor calibration: myth or reality?

Many users are looking for ways to calibrate the sensor so that it can “listen” again. In reality, on today’s Xiaomi capacitive screens, software calibration through third-party apps from the Play Market is often inefficient. These applications only create a virtual layer on top of the system that can even make things worse.

The real calibration is done in the factory and is recorded in the controller's memory, and it's extremely difficult to knock it down, but if the sensor doesn't work properly after the screen is replaced, there's an option in the engineering menu (#64663###) called "Touch Calibration," which can help the system re-definition the boundaries of the active area.

You have to differentiate between calibration and sensitivity. Some Redmi models have hidden settings or design themes that change the touch processing algorithms. Try changing the theme to the standard one, because sometimes custom themes contain bugs that affect the response of the screen.

When is the time to bring your phone to service?

There are a number of signs that indicate that self-repair is useless and dangerous. If you see physical damage to the matrix (black spots, stripes), broken glass with sharp edges or the phone began to warm up in the area of the camera even when it is turned off, immediately carry it to the master.

Also, the reason for contacting the service is a situation when the sensor stopped working after an unsuccessful attempt to replace the battery or screen on its own, in which case the plume may have been damaged or the controller affected, and professional soldering or replacement of components is required.

Don't ignore the problem if the sensor is "living its life." Chaotic taps can lead to locking the device, erasing data, or even trying to reset passwords. It's better to temporarily turn off the Internet and use an external mouse to control until you resolve the repair issue.