Buying a new gadget from a popular Chinese brand is always an exciting process, with certain risks. The electronics market is oversaturated with offers, and even in authorized points of sale or large marketplaces you can encounter low-quality goods, restored devices or outright replicas. Careful inspection of the device immediately after opening the box will allow you to avoid long disputes with the seller and return money if something is wrong with the device.
Many users make the mistake of starting to use the device actively without initial diagnosis. The appearance may be perfect, and the box is sealed, but inside there may be software failures or hidden defects in the matrix that will manifest themselves only after a week of operation. To prevent this from happening, you need to act systematically, following a clear algorithm of actions, which we will describe below.
In this article, we will cover all the steps from visual inspection of the package to deep testing of hardware through the MIUI and HyperOS engineering menus. You will learn how to authenticate the device using IMEI, assess the build quality and make sure that the battery does not have critical wear.
Visual inspection of packaging and configuration
The first familiarity with the device begins long before the screen is turned on. The box is the first indicator of the quality and originality of the product. The original packaging of Xiaomi, Redmi or POCO is always made of dense cardboard with a clear, high-quality print. It should not be blurred fonts, typos or skewed logos. Pay special attention to stickers: at the bottom of the box or on the end should be information about the model, color, memory capacity and IMEI (often in the form of a barcode).
When opening, pay attention to the organization of the internal space. The components should be tight, but without undue pressure, in special recesses or on cardboard substrates. The presence of foreign debris, dust under the protective film or autopsy marks (damaged seals, ripped tape) is an alarming signal. If you buy a device not in the official store, compare the package with the description on the official website, as in different regions the supply may vary.
⚠️ Note: If the box does not have factory seals or there are traces of re-gluing, refuse to buy. This may indicate that the device has already been used, returned by a previous buyer or is refurbished, which should be indicated by the seller explicitly.
Inside the box you should find the smartphone itself, the warranty card, the instruction (often in the form of a booklet in several languages), the clip for extraction. SIM-card and charger with cable. USB The charger must be clearly marked with input and output parameters, as well as certification marks.
IMEI authentication and serial number
One of the most important steps is to verify the unique device identifier. IMEI (International Mobile Equipment Identity) is a unique number assigned to each mobile phone. It allows you to track the history of the device, its warranty status and authenticity. On new Xiaomi smartphones, the IMEI number is usually listed on the sticker on the box, on the back cover (if it is removable or transparent) and on the system menu.
To get the code from the device, dial the universal command *#06# in the Phone app. SIM-map IMEI. These numbers should match perfectly with the ones printed on the box, and even a single digit difference means that the device is either assembled from different parts, is a fake, or has been re-filmed by artisanal methods.
Once you receive the number, you need to check it through official services, this can be done on mi.com/global/verify or in the About section of the system settings if the device is connected to the Internet. The system will show the warranty activation date, model and color. If the system says that the device was already activated several months ago and you bought it as a new one, this is a reason for an immediate return.
| Parameter | Where to find out. | What to pay attention to |
|---|---|---|
| IMEI 1 | Set *#06#, sticker on the box | 100% matching across all sources |
| Serial number (SN) | Settings → About the phone, the box. | Absence of lost devices in databases |
| Model | Settings → About the phone | Compliance with the claimed (e.g. 2201123G) |
| Activation date | Official site of the inspection | The date must be the same as the date of purchase or later. |
What to do if IMEI is not readable?
Diagnostics of the screen and sensor for defects
The screen is the most expensive and fragile component of a smartphone. Even if the glass is visually whole, there can be problems hidden beneath it: broken pixels, uneven backlights or dead zones of the touchscreen. First, turn on the device and set the brightness to maximum. Open a white image (through Google Pictures) and carefully examine the surface in good light. Look for points of a different color, spots or yellowness.
Next, you need to check the multi-touch and the sensitivity of the sensor. MIUI And HyperOS has a built-in engineering menu to test. To get there, go to settings, select About Phone, and quickly click on Version several times. MIUI» (or "Version" OS»), Until you say, "You're a developer," and then you'll see "Extended Settings" in the "Additional" menu, where you'll find "Kernel Version" and click on it. 5-7 once-in ##6484## ring-bell.
In the CIT (Customer Interface Test) menu that opens, select "Touchpanel" or "Display." Follow the on-screen instructions: You usually need to swipe all the squares or draw lines, which will help identify areas where the sensor does not respond to touch. This menu often includes a vibration test and buttons, which allows you to check the physical integrity of the interface.
⚠️ Note: When checking the screen, pay attention to the “ghost touch” (ghost touch). If the phone itself reacts to touch when you do not touch it, or the cursor twitches, this is a defect in the matrix or plume that will progress over time.
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For more detailed checks, use the Play Market Screen Test app, which allows you to run colors (red, green, blue) separately, which helps to identify broken pixels that are not visible on a white background.
Testing of camera, speakers and microphone
The quality of your photography and sound are key comfort factors. Start checking your camera with a standard app. Take a few shots in good light and when there's not enough. Pay attention to focus: point the camera at the text close and far, check if there's soap around the edges of the frame. Switch to video mode and record a short clip as you walk around the room, and that will check the stabilization and autofocus in motion.
The sound subsystem is tested in a complex way. Turn on music or video at maximum volume. The sound should be clean, without wheezing, cracking and distortion, even at bass frequencies. Check all the speakers: the main (bottom), spoken (top) and additional (if stereo). Then open the recorder and record your speech, then listen to the file. This will confirm the performance of the main and additional microphones (noise suppression).
Don't forget to check the vibrator. The CIT engineering menu has a separate "Vibrator" test, but you can do with standard settings. The vibration should be clear, without rattling the body. If the phone is new, foreign rattles are unacceptable and indicates a poor build or defect in the component.
☑️ Multimedia Express Check
Verification of communication modules and sensors
Smartphone is primarily a means of communication, so check SIM-Maps and communication modules are mandatory. SIM-Check the signal level, try incoming and outgoing calls, the quality of the communication should be stable, without interruptions and echoes. If you have two SIM cards, check to switch between them and the ability to transfer data over the mobile network (3G/4G/5G).
Wi-Fi and Bluetooth modules deserve special attention. Connect to your home Wi-Fi network and check the Internet speed. Walk around the apartment: the signal should not be lost two meters from the router. For Bluetooth, connect headphones or smartwatches. The device should be fast and stable connection. Also check the GPS: start the maps and determine your location - the point should be determined quickly and accurately.
Sensors are subtle but important components. Check the proximity sensor: during the call, hold your hand to the top of the phone, the screen should go out. The light sensor is checked by changing the brightness of the screen when you close the top of the smartphone with your palm. The accelerometer and gyroscope are checked by turning the screen and playing games with tilt control.
In the CIT engineering menu, there's a Sensor section where you can see all the sensors in real time, and when you tilt your phone, you should see the changes in the accelerometer values, and if the values don't change or if they jump without moving, the sensor is faulty.
Analysis of battery and system status
The final step is to test the energy efficiency and the software, and the new smartphone needs to keep the charge confident, but to understand the actual state of the battery, you can use special utilities or engineering codes ##6485## You'll see a menu with technical information. MB_06 (Battery status: it should say "Good." Parameter MF_02 The number of charging cycles will show: the new device should have few (usually before) 5-10, Because the factory is testing).
Check the heating of the case when you're working. Run a heavy app or game for 10-15 minutes. The phone may get hot, but it shouldn't burn your hands or turn off spontaneously. Excessive heating in a simple or light task is a sign of a defective processor or cooling system problems.
⚠️ Note: If the battery menu (code ##6485##) parameter MB_06"Bad or Replace, and Charging cycles (MF_02) hundreds - you sold a used device with a replaced, but poor-quality battery or a restored device.
Also worth checking is the Android version and security level. Go to Settings → About Phone. Make sure you have the current version of the shell installed. If a new phone bought in 2026-2026 is running Android 10 or 11, it's suspicious. Update through Settings → System Update to rule out critical vulnerabilities.
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A comprehensive check takes about 20-30 minutes, but saves months of using a faulty gadget.