Buying a new smartphone is always exciting, especially when it comes to popular brands such as Xiaomi, Redmi or POCO. Devices of these brands are famous for their excellent price-performance ratio, but the risk of facing a marriage or a restored instance persists even when ordering in official stores. Careful checking of the gadget in the first minutes after unpacking is not paranoia, but a reasonable need that will avoid long return procedures and damaged nerves.
Many users make the mistake of using their phones without initial diagnosis, relying on factory quality control. Unfortunately, manufacturing defects do happen, and logistics can add to their problems in the form of bumps or temperature changes, which is why external and software inspection should become your number one habit.
In this article, we’ll break down a detailed algorithm that will help you identify hidden screen defects, check your sensor, assess battery status, and verify your device’s authenticity. You’ll learn to use the built-in MIUI and HyperOS diagnostic tools to be sure of your purchase.
External inspection and configuration check
The first thing you should do when you get the box in your hand is to look carefully at the condition of the box. The package should not have any opening, dents or moisture damage. Pay attention to the protective seals: if they are broken or missing, it is a reason to think about the origin of the product. Even small scuffs at the corners of the box can indicate that the device has been dropped or transported incorrectly.
When you open the box, take your time to turn on the device. First, visually inspect the smartphone itself. Carefully examine the case from different angles in good light. The glass, frame and back should not be scratched, chipped or scuffed. Pay special attention to the area around the camera lenses and speakers, where dust accumulates most often or finger marks remain if the phone has been used.
Check all the components, depending on the model and the region of sale, the box may contain a charger, cable. USB, cover, paper clip for extraction SIM-The absence of a cable or charger (which is becoming the norm for flagship models) should be specified in the specification, but if a paper clip or warranty card is missing, this is an alarm signal.
⚠️ Warning: If you find a hair, villi or air bubble under the film on the screen that does not disappear, this may indicate poor-quality factory assembly or replacement of the display module in artisanal conditions.
Make sure the tray is for SIM-The card opens easily and matches the color of the case. The mechanism should work smoothly, without jamming. Also check the volume and on buttons: they should have a clear stroke and emit a characteristic click, not fall or dangle.
☑️ Initial inspection of the device
Turning on and checking the display
After a successful external inspection, you can start the first run. Press the power button and wait for the logo to appear. The screen should light up evenly, without blinking or strange artifacts. The modern AMOLED and IPS arrays used in Xiaomi smartphones are highly detailed, but they are also sensitive to mechanical stress.
To thoroughly check the display, use the built-in engineering test. Type ##6484## in your phone or go to Settings → About Phone → Kernel Version (the path may vary depending on the version of MIUI). Select the item associated with the display check (usually called "Display" or "Screen").
In the test mode, the screen will be consistently colored in different colors: white, red, green, blue and black, and your task is to look at the surface carefully at each color. On a white background, you can see broken pixels (dots that burn with a different color or do not burn at all) and uneven backlights. On a black background in a darkened room, you can see the lights around the edges or the “lightlight effect” characteristic of some people. IPS-matrix.
What are broken pixels?
Also check the automatic brightness control. In the engineering menu or in the usual settings, try to change the backlight level from minimum to maximum. The scale should move smoothly, without jerking. The minimum brightness should be comfortable to read in the dark, and the maximum brightness should be readable in the sun.
The screen refresh rate deserves special attention. If you buy a model that supports 90 Hz or 120 Hz, make sure that this feature is active. Go to Settings → Screen → Update and choose “Maximum” or “Auto”. Scroll through the news feed or settings – the movements should be smooth and responsive.
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Color uniformity and the absence of broken pixels are the main screen quality criteria that must be checked in the first 14 days, while the law on the return of goods of good quality (in the presence of a defect) is in force.
Testing of touch screen and multi-touch
The touchscreen is the interface to your smartphone, and any problems with it make the device virtually useless. In the CIT engineering menu (called ##6484##), find the Touch sensor or Single touch test.
The test is simple: you need to swipe your finger across all areas of the screen, the line should be drawn continuously, without tears or jumps, and pay special attention to the edges of the screen, because that's where the responsiveness problems often arise due to design features or protective glasses.
Next, check the multi-touch. In the same menu, select "Multitouch." The screen will suggest touching it with several fingers at once. Modern Xiaomi smartphones support simultaneous recognition of 10 touch points. Make sure the device sees all your fingers and correctly displays their position.
If you plan to play mobile games actively, do a little stress test. Run a demanding app and try swiping, zooming, or typing quickly. There should be no delays, cursor sticking, or spontaneous taps.
- 🔍 Swipe your finger diagonally on the screen – the line should be perfectly flat.
- 🖐️ Touch the screen. 5-10 fingers at the same time – all points should be displayed.
- 📱 Check the response to touch in the corners of the display where the controls are often located.
- 💧 Make sure the screen doesn’t respond to wet fingers inadequately (although it’s more of a test for a hydrophobic coating).
Checking cameras, speakers and microphones
Multimedia capabilities are one of the key reasons for buying Xiaomi smartphones: Start with the cameras, launch the Camera app and take some pictures in good light, then in low light. The photos should be clear, without unnecessary noise and blur (except when using portrait mode).
Be sure to check all the modules: main, wide-angle, telephoto and macro camera, if you have them in your model. Switching between the lenses should be quick and without delay. Also test autofocus: point the camera at the text close and away - focusing should be instantaneous.
Make a short video with stabilization enabled. Walk around the room, turning the phone from side to side. The picture should be smooth, without twitching. Check the zoom when recording the video - the image should not "swim".
⚠️ Note: If you see purple spots or iridescent glare when you point the camera at light objects, this may indicate an IR filter problem or optics quality, which is the reason for replacing the device.
Now, to the sound, play music or video at maximum volume, speakers should sound clean, without wheezing, cracking, or rattling, check both speakers (bottom and top) if you have a stereo, and the sound should be even.
To check the microphones, turn on the recorder and record your voice in a quiet room and outside. Then play the recording. The voice should be legible, without strong wind noise or interference. Remember to check the noise cancellation during a conversation by calling someone or yourself.
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When testing cameras, not only take pictures of static objects, but also fast-moving objects (for example, swipe your hand in front of the lens), which will help to identify problems with shutter speed and lubrication of the frame.
Diagnostics of communication modules and sensors
A smartphone is a communication device, so checking Wi-Fi, Bluetooth and cellular is critical. The CIT engineering menu has separate tests for each module. Run a Wi-Fi test: the phone must find available networks. Connect to your network and check Internet speed by opening a heavy site or high-resolution video.
Bluetooth check is also a must, especially if you use a wireless headphone or watch.Try to transfer the file to another device or connect the headset.The signal should be stable, without permanent connection breaks.
The most important step is to check the sensors. In the diagnostic menu, select "Sensor." You will be asked to check the accelerometer (screen rotation), the gyroscope, the proximity sensor (screen goes out when you touch your ear) and the light sensor. The proximity sensor is often a criticism from Xiaomi users, so test it several times by covering the top of the screen with your palm while simulating a call.
Check GPS/GLONASS. Open maps (Google Maps or Yandex.Maps) and click on the location icon. The point should appear quickly and accurately match your real location. If you are indoors, go outside or go to the window for better reception of the signal.
Remember to check the USB Type-C charging connector. Connect the cable and swing it from side to side. Charging should not be interrupted, and the computer should not connect or disconnect the device. Also check the vibrator - the vibration should be palpable, but not rattling.
Why do you need a Hall sensor?
Battery and performance check
The final test is to evaluate the battery and overall system performance, and while it's a myth to fully discharge and charge a new phone for calibration, it's not superfluous to check the actual capacity and charging speed. Look at the percentage of charge you turn on. Usually, new devices come with a charge of about 40-60%.
Connect the original charger. The fast-charging logo (like Quick Charge, Power Delivery or Xiaomi’s logo with lightning) should appear on the screen. The phone should heat moderately. Heavy heating in the idle or when charging is a sign of malfunction.
To test performance, you can run benchmarks like AnTuTu or Geekbench. Compare that to your model's benchmarks on the Internet. An underrated score can indicate CPU issues, overheating, or background processes that eat up resources.
The table below gives approximate values that should be guided when checking popular series (values can vary depending on the version of the software):
| Xiaomi Series | Expected AnTuTu (v10) | Type of charging | Features of the inspection |
|---|---|---|---|
| Xiaomi 13/14 Series | 1,500,000+ | 67W - 120W | Checking the heating during fast charging |
| Redmi Note 12/13 | 400,000 - 600,000 | 33W - 67W | Screen Stability Test (PWM) |
| POCO F5/F6 | 900,000+ | 67W | Processor stress test in games |
| Redmi 12/13 (budget) | 250,000 - 350,000 | 18W - 22.5W | Checking the responsiveness of the interface |
Light heating in the area of the processor (usually the top of the smartphone) is acceptable, but if the phone gets so hot that it is unpleasant to hold in your hand, this is a cause for concern. Also pay attention to battery consumption in the first hours: it should not be abnormally high (more than 1-2% per hour in standby mode).
Authentication and resetting
Once you are satisfied with the technical serviceability, you need to verify the authenticity of the device. On the box and in the Settings menu → The phone must match IMEI-codes. You can check them on the official Xiaomi website in the authentication section. Enter IMEI and serial number - the system must confirm that the device is original and was not activated before (or show the date of the first activation).
Another important point is that there's pre-installed junk or weird apps. Global firmware versions may contain ad apps, but if you see Chinese services on the global version or strange app names, it could be a sign of a re-stitched device.
After all the checks, if you plan to keep your phone, it is recommended to perform a full data reset (Wipe all data), which will delete all your test photos, contacts and settings, returning the device to the state "out of the box", but with confidence in its serviceability. → Advanced settings → Recovery and discharge → Delete all data.
⚠️ Warning: Before resetting, be sure to log out of your Mi Account and Google account.Otherwise, anti-theft protection will work, and after resetting, the phone will require you to enter passwords you may not remember.
If you find a critical defect (a broken pixel in the center of the screen, a broken microphone, communication problems), do not reset immediately. Take photos and videos of the defect, save checks and go to the store. The presence of traces of active exploitation (your personal photos, installed applications) can complicate the return procedure, so the initial diagnosis is better done on a clean device.
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The IMEI matching on the box, in the settings and on the manufacturer’s website ensures that you bought the original device, not a restored copy.