Touch screen is the most vulnerable element of a modern smartphone, and Xiaomi devices are no exception: Regular use, accidental falls or just wear over time can lead to “dead zones”, chaotic taps or complete sensor failure.
Fortunately, MIUI and HyperOS have built-in hardware testing tools, so you don't have to take your phone to the service center right away to see what's going on. There are several ways to do a deep screen diagnosis right on the device, using hidden menus or special utilities, to help you determine if the problem is software or if you need a touchscreen replacement.
In this article, we will take a look at all the test methods available, from simple tests to engineering codes, and learn how to distinguish a software failure from physical damage, and how to calibrate the screen to restore its sensitivity.
Using the Engineering Menu for Diagnostics
The most reliable way to test the health of all components of a smartphone, including the display, is to use the built-in engineering menu, which is available on Xiaomi devices through the standard Phone application. To start the diagnosis, you need to enter a special combination of characters that opens access to hidden functions of the system.
Enter ##6484## or ##4636## in the dial box. Once you enter the last character, the menu should open automatically. If that doesn't happen, your firmware may restrict access to these features, and then you'll have to use third-party apps. The CIT (Customer Integration Test) list that opens will look for the item associated with the screen, usually called Touchpanel, Touchscreen, or just Display.
Once you select the appropriate item, you'll see a test field, most often a white or black area that responds to touch, you'll need to swipe your finger across the entire surface of the screen to make sure that the response is uniform, and if a line breaks in some area or the cursor is shaking, that's a direct sign of a matrix or plume malfunctioning.
⚠️ Warning: Do not change the settings in other sections of the engineering menu unless you are sure of your actions. Accidental resetting of the calibration or changing the network parameters may lead to malfunction of the device.
Checking through MIUI system settings
Not all users know that the MIUI shell has a built-in partition to check the state of the device that does not require code entry. This method is more secure for beginners, since it eliminates the risk of accidental changes in system parameters. To get there, go to Settings → About → All settings → Version of the kernel. Quick multiple taps (5-7 times) on the line “Kero Version” will start the testing menu.
The interface of this menu may vary depending on the firmware version, but the logic of the work remains the same: you will be asked to take a number of tests, including color, multi-touch and sensitivity checks. Multi-touch is the ability of the screen to recognize multiple simultaneous touches, which is critical for games and image zooming.
In the test, the system may ask you to press certain points or draw lines in specified directions. If the screen is delayed or misses touches, the system will issue a warning, which is a great way to quickly assess the overall state of the digitizer without installing additional software.
💡
If the screen is not responsive, try temporarily turning off the protective glass or film. Thick protective coatings often reduce the sensitivity of the sensor, especially at the edges of the screen.
Third-party apps for touchscreen testing
If the built-in tools don't seem informative enough or unavailable, Google Play apps will come to your aid. There are many tools designed specifically to test touch screens in detail, and they provide more flexible settings and detailed response statistics.
One of the most popular apps is the Touch Screen Test, which allows you to check the number of simultaneous touches (multi-touch), determine the accuracy of positioning and identify “dead zones.” Another useful application is the Dead Pixel Test, which, in addition to checking for broken pixels, often has a sensor check mode.
The advantage of third-party programs is that they can display the coordinates of the touch in real time, which helps you understand how accurately the finger matches the cursor. If you see that the touch point is shifted 2-3 millimeters to the side, this may indicate a need for calibration or a problem with the magnetic field next to the screen.
☑️ Checking with third-party software
Detailed table of codes and functions
For the convenience of users, we have compiled basic codes and features that may be needed in the diagnosis, and it is important to understand that the set of instructions can vary depending on the CPU model (Snapdragon or MediaTek) and the version of Android.
| Team/Code | Function | Description of action |
|---|---|---|
| ##6484## | CIT Menu | Complete diagnosis of all components, including touchscreen. |
| ##4636## | Testing | Phone, battery information and usage statistics. |
| ##7780## | Factory Reset | Resetting settings (use with caution!). |
| ##232338## | WiFi MAC | Display MAC-Wi-Fi module addresses. |
Using these codes allows you to quickly access hidden features. However, remember that some commands, such as data resets, can lead to loss of information. Always check which feature you are running before confirming an action.
Screen calibration: when you need it
Calibration is the process of adjusting the sensor sensitivity and aligning the touch coordinates, which is necessary if you notice that the phone responds to touch in the wrong place where you press, or if the sensitivity has become too low. In modern versions of Android, manual calibration is rarely required, but in cases of severe failures it can help.
There's a myth that calibration can bring a broken screen to life. It's not. If the glass is broken or damaged, the touch layer itself, software methods won't help. Calibration only works with software failures when the system misinterprets signals from the right equipment.
You can use the engineering menus we talked about above, or apps like Touchscreen Calibration, to calibrate, and the process usually involves consistently tapping crosses that appear in different parts of the screen, and when you're done, the phone can suggest a reboot.
Why is the calibration going wrong?
⚠️ Warning: If the problem persists after calibration, the physical touchscreen layer is likely to be damaged, in which case only a replacement module at the service center will help.
Causes of malfunction and prevention
Understanding the causes of touchscreen problems will help avoid them in the future, most often culprits are mechanical damage, moisture or the use of poor-quality chargers, and cheap power supplies can cause severe interference, which causes the screen to “live its life” while charging.
Also worth mentioning is static electricity. In dry rooms or in winter, when we wear synthetic clothing, the accumulated static charge can temporarily disrupt the capacitive screen. Usually this goes away on its own, but regular discharges can shorten the life of the sensor.
For prevention, it is recommended:
- 🧼 Regularly wipe the screen with a soft microfiber cloth, removing fat and dust.
- 🔌 Use only original or certified chargers.
- 🛡️ Stick a quality protective glass that will take the blow when falling.
💡
The use of original accessories and protection from mechanical damage prolong the life of the touchscreen by 2-3 times.