How to check Xiaomi phone: diagnostics and tests

Buying a Xiaomi or Redmi smartphone is often a great solution because of its high price-to-quality ratio. However, the electronics market is oversaturated with refurbished devices, models with hidden defects and even outright fakes that look almost indistinguishable from the original, which makes the question of how to check the phone before buying or after receiving a parcel critical for every user.

There are many methods of verification, from simple visual inspection to deep software diagnostics through hidden engineering menus, a comprehensive approach that will reveal problems with the display, battery, camera, and even determine whether the case has been opened before, ignoring these steps can lead to the purchase of a device that will fail in a couple of months.

In this guide, we will discuss all the available methods of testing, you will learn how to use the built-in tools of the system, secret methods of testing. USSD-teams and third-party utilities to get a complete picture of the state of the gadget. IMEI-code on the official website MIUI and in the system menu at the same time.

Visual verification and reconciliation IMEI-code

The first thing to start with is a careful external inspection and verification of unique identifiers. Any Xiaomi device has a unique IMEI number, which is stitched into the chip and indicated on the box, and the inconsistency of this data is the first sign of problems.

Find the sticker on the back of the box and compare the 15-digit number to what's displayed on the screen. To do this, type the universal code *#06# in the Phone app. If the numbers match, it's a good sign, but not a guarantee of 100% authenticity, since IMEI can be reflashed.

• 📱 Check the density of the tray fitting SIM-maps and the presence of backlash volume buttons.
• 👁️ Carefully inspect the camera lenses for dust inside the glass or scratches.
• 🔌 Charging connector USB-C should sit tightly, without visible traces of oxidation or mechanical damage.

Also worth paying attention to the build quality: the original Poco and Redmi models have minimal screen-frame gaps, and no glue protrudes, and if you notice autopsy marks or irregular gaps, chances are the phone has already been repaired.

⚠️ Note: If you enter the code *#06# The number is not displayed or displayed as "Null/Unknown", This is a sure sign of a re-stitched or counterfeit device with a modified software shell.

Using the CIT Engineering Menu for Testing

The most powerful tool for checking the phone is the built-in CIT (Customer Integration Test) menu, which allows you to test each device module separately, which is especially useful when looking for hidden defects.

To enter the diagnostic menu, open the Phone app and dial the combination ##6484##. Some models trigger the code ##4636##, which opens the testing menu. If the codes don't work, you can try to go through the Settings path → About Phone → All specs → Version of the kernel (click many times).

In the list that opens, select the component you want, for example, the Touchpanel test will help you identify the dead zones of the screen, and the Vibrator test will show you whether the recoil mechanism is working.

Don't ignore sensor tests like the accelerometer and the gyroscope. If the phone is lying about its position in space, the navigation and autorotation of the screen will not work properly. You can often see the calibration of these elements in the CIT menu.

Checking the display for broken pixels and touchscreen

The screen is the most fragile and expensive element of a smartphone. Even if the glass is whole, the matrix can have defects that you can't see on a cursory inspection in a store.

In the engineering menu, select the LCD or Display test. The screen will start to cycle colors (red, green, blue, white, black). Look closely at the surface: any dots that burn with a different color or do not change shade are broken pixels.

• 🔴 Look for constantly burning red, green, or blue dots.
• ⚫ Pay attention to black dots that do not light up on a white background.
• 🌈 Check the uniformity of the backlight, especially at the edges of the screen (the "background" effect").

The multi-touch test is also worth checking, and there's a test on the CIT menu where you can diagonally swipe your fingers or draw certain shapes, and if the lines are interrupted or shake, the digitizer is damaged or of poor quality.

⚠️ Warning: Broken pixels can only appear after the matrix is heated. 10-15 minutes before a careful screen examination on a white background.

Diagnostics of battery and charging system

Battery health is a key factor in smartphone longevity. The MIUI and HyperOS shells don't have an exact percentage of wear (SOH) widget built in, like the iPhone, but you can get the data through system logs.

Dialer code in dialer code ##6485##. You'll open a window with technical information. You'll be interested in parameters. MB_06 (battery-state: Good/Normal) and MF_02 (Number of charging cycles. Parameter is also important. MF_05 — actual battery capacity in mAh.

For a deeper analysis, you can use ADB-The adb shell dumpsys batterystats command will give you a detailed log, but for the average user, third-party applications like AccuBattery, which calculate wear based on charging history, are more convenient.

Pay attention to charging speed. If your Xiaomi supports fast charging of 67W or 120W but charges slowly, check the cable and power supply. The Battery menu should display a message to turn on the turbo charge.

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To extend the life of a lithium polymer battery, try not to drain the phone below 15% or keep it constantly charging at 100%, especially in hot conditions.

Performance analysis and memory tests

Checking your phone for performance is necessary to make sure you haven’t bought a fake with stripped-down hardware.Chinese copies often have a modified build.prop file that shows the flagship processor in the settings, although there is a cheap counterpart inside.

Use benchmarks like AnTuTu or Geekbench. Compare that to the benchmarks for your model on the Internet. If the difference is more than 20-30%, that's a good thing to be wary of. Also check the amount of RAM and internal memory.

Go to Settings → About the phone and see the available memory. If it's 128 GB declared and the system is showing about 110 GB freely (after installing a couple of applications), that's OK. If you only have 10-15 GB available at 128, then the memory has been reprogrammed by the controller to display a false volume.

adb shell cat /proc/mtd

This command will show the real size of the memory partitions through ADB, and for a normal check, you just need to install the Device Info HW application, which reads data directly from the controller, bypassing system “hacks”.

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Real performance is only tested in heavy tasks (games, rendering) and benchmarks; beautiful numbers in Settings are easy to forge, benchmark data is much more difficult.

Authentication check on the official website

The final step is to verify the device on the manufacturer's servers, and this is the easiest way to test the phone for originality without having the technical knowledge.

You'll need it. IMEI-code (can be found on the box or under the battery if it is removable, but it is better to take from the menu *#06#). Go to the official verification site mi.com/global/verify regional support site.

• 🌐 Enter. IMEI site-field.
• 🔢 Enter the captcha to confirm that you are not a robot.
• ✅ Get the result: Valid (valid) or an error message.

The system will also show the date of the first activation of the device, and if you bought a new phone and the site says that the warranty began six months ago, then you sold a used device or a restored copy (Refurbished).