Fully check Xiaomi devices for performance: from screen to processor

Buying a Xiaomi device — whether it’s a Redmi Note 12 smartphone, a Mi TV Q2 or a Mi Band 8 smartwatch — always carries the risk of getting a defect, a fake or a used product that is being passed off as a new one. Even in official stores, there are devices with factory defects, not to mention the secondary markets. This article will help you systemically test any Xiaomi device — from the budget Poco M6 to the flagship Xiaomi 14 Ultra — to identify hidden problems before payment.

We'll look at not only basic checks like power on and charging, but also deep diagnostics: battery wear tests, screen tests for broken pixels, camera analysis with service codes, and how to identify replacement parts. We'll focus on software tests (via ##4636## and Mi Check) and hardware methods, from body inspection to multimeter connectors, and if you buy a device from hand, these instructions will help you avoid being cheated by 90%.

1. External inspection: what gives out a fake or repair

Start with visual analysis of the case and packaging. Xiaomi's original devices have clear seams between the body parts, a uniform gloss (or matteness for the Note series), and factory stickers with IMEI that match the data in the system.

• 🔍 Uneven gaps between the screen and the frame (especially in Redmi and Poco).
• 🎨 Color mismatch: for example, the back cover is darker than in the official photos.
• 📦 Box without hologram or with typos in the model name (for example, "Xioami" instead of "Xiaomi").
• 🔧 Screen pasting traces: at an angle to the light, bubbles or uneven glue are visible.

Note the serial number, which must match the box, the battery (if removable) and the Settings → About phone menu. Use the official Mi Verify service to authenticate your device. If the device is already activated, ask the seller for adb logcat logs to show how many times the phone has been rebooted (frequent reboots may indicate battery or motherboard problems).

⚠️ Note: On Xiaomi devices with AMOLED-screens (e.g. Xiaomi) 13T) Check the burn effect -- turn the white background on at maximum brightness and look at it from an angle. If you can see the contours of past interfaces (like keyboards), the screen is worn out.

2. Screen check: broken pixels, backlight, sensor

The screen is the most vulnerable element, and its defects are often hidden. Use special templates (you can find the "LCD test image") or the Screen Test app from Google Play to test.

1. Color tests: Alternately display red, green, blue and black backgrounds, and on a black background, broken pixels (white or colored dots) are clearly visible.
2. Gradient: A smooth transition from black to white will reveal "banding" (banding) - a sign of a cheap matrix.
3. Sensor: In the Touch Screen Test, swipe your finger across the area – delays or “dead zones” will indicate problems with the digitizer.
4. Brightness and backlight: Turn on the flashlight and light it at an angle. Uneven backlights (yellow spots) are characteristic of cheap lighting. IPS-panels in Redmi models 9A.

For AMOLED-Check the uniformity of black in the dark room at minimum brightness should not be gray. Also test the refresh rate: go to Settings → Screen. → Update frequency and turn on 120Hz. If the screen starts to "shake" or artifacts appear, this is a sign of a graphics chip malfunction.

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If Xiaomi’s screen is green when viewed from an angle, it’s not always a marriage, as IPS-matrixes with Sunlight Display technology (for example, in Redmi Note 11) are a feature.

Battery Testing: How to Detect Wear and Counterfeiture

The battery is the second most important component after the screen, and even if it's new, it could have been in storage for years and lost capacity.

• 🔋 Code ##4636##: In the Battery Information menu, check the charge level (should match the indicator), temperature (normal 25–40)°C) and voltage (4.2–4.4V 100%).

A critical sign of a fake battery is the lack of marking with a production date (YYMM format) and the Xiaomi logo. Also check the charging cycles through the engineering menu (code ##284## on some models). If the value exceeds 300-500 cycles, the battery is close to replacing. For devices older than 2 years, normal capacity is at least 80% of the factory capacity.

View the production date on the sticker | Check the voltage in the engineering menu | Run the test in AccuBattery | Estimate the time of full charging | Check the temperature when charging-->

⚠️ Note: If the Xiaomi device heats up above 45 when charging°C (checked in AIDA64), This may indicate a malfunction of the power controller or the use of an unoriginal cable, especially for models with fast charging. 120W (for example, Xiaomi 12S Ultra).

4. Camera diagnostics: from focus to infrared sensor

Xiaomi cameras are often faked, installing cheap modules instead of the stated ones (for example, instead of Sony IMX766 in Xiaomi 11T Pro, there may be a Samsung GW3).

1. Compare the photo examples with the official Mi Community website, and note the detailing in the shadows and color rendering.
2. Test all modules: 📸 Main camera: take a photo of text from a distance of 30 cm - there should be a clear focus. 🌃 Wide-angle: Check for distortions at the edges (norm to 10%). 🔍 Macro: zoom in on the object by 2-3 cm - details should be sharp. 👁️ Front: Enable Portrait Mode – background blur should be uniform.

Check service codes.

For the main camera: ##6484## (on some models)


For the infrared sensor test: ##2663###

Pay special attention to autofocus: in the Camera MX app, turn on Pro mode and touch the object in different parts of the screen. Focus delay of more than 1 second is a sign of malfunction. Also check stabilization: record video in 4K while walking - shaking should be minimal (in Xiaomi 13 Pro uses OIS + EIS).

5 Performance tests: processor, memory, network

Even if the device looks good, the hardware problems may come later.

• 🖥️ Processor and GPU: Run an AnTuTu Benchmark or Geekbench 6. Compare the results with benchmarks for your model (e.g., the Snapdragon 8 Gen 2 in Xiaomi 13 should type in). ~1,200,000 in AnTuTu).
• 💾 Memory: in AIDA64 check the type UFS (must match official specifications) and read/write speed (e.g, UFS 3.1 grant ~1500 MB/s).
• 📶 Network: Insert SIM-Check the speed test in Speedtest (should be tariff-appropriate) and call the device, if the sound is intermittent, there may be antenna problems. 5G (If supported, check the stability of the connection.
• 🔊 Speakers and microphone: record voice in Voice Recording and listen - there should be no wheezing or echoing. For the speaker test, use a frequency test (20 Hz - 20 kHz).

Note the heat output: run 3DMark for 10 minutes – if the CPU temperature is above 70°C (checked in the CPU Monitor), this is a sign of heat paste problems or a malfunction of the cooling system. Also check the multi-touch test: in MultiTouch Test, simultaneously touch the screen with 5-10 fingers – all touches should be displayed.

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If the result in AnTuTu is below the reference by 20% or more, this may indicate a trottling (performance restriction due to overheating) or a non-original processor.

6. Software and firmware originality verification

Fake or "grey" Xiaomi devices are often sold with custom firmware that hides the real state of the iron.

1. Check the MIUI version in Settings → About Phone. It should match the latest stable build for your model (see the official website for the current versions).
2. Run the command: adb shell getprop ro.miui.ui.version.name If the version does not match the menu, the firmware is modified.
3. Check the IMEI: Dial *#06#, which should show the same IMEI as the box. If the IMEI starts with 000000 or 860000, the device is not original.

Mi Check

Xiaomi

Pay special attention to unlocking the bootloader: if Settings → Additional → OEM Unlock is enabled for developers, the device could be in repair or used for mining. Also check the Google license: Settings → Google → Google Play Services must be ticked “Certified”.

⚠️ Note: If the menu is Settings → Memory displays less memory than claimed (e.g. 112GB instead of 128GB), this may be due to partition re-marking after unofficial repairs or use of the device for service purposes.

7. Testing of additional functions (NFC, IR port, sensors)

Many Xiaomi devices come with additional modules that are rarely checked when buying.

• 💳 NFC: Try to pay contactlessly (e.g., through Google Pay). If it doesn't work, check the settings in Settings → Connected devices → NFC.
• 📺 IR port: download Mi Remote and try to control the TV. On Xiaomi 12 and newer, the IR port is often absent - check the model specifications.
• 🧭 Sensors: Gyroscope: in Sensor Test, tilt the device, the ball should move smoothly. Compass: in Google Maps, check the accuracy of the detection of light points. Approximation sensor: during a call, the screen should go out when you bring it to your ear.
• 🔋 Wireless charging (if supported): put it on the charging station – a notification “Air Charging” should appear".

For devices with Ultra Wideband (UWB) (such as Xiaomi 13 Pro), check the Mi Smart Tag 2 – the location accuracy should be within 10 cm. If the sensors are not working properly, this may indicate problems with the motherboard or damage to the plumes.

8. Check for hidden problems (log files, usage history)

To identify hidden defects or traces of repair, use the service tools and system logs:

1. Use the Mi Flash Tool: connect the device in Fastboot mode and check the status of locked/unlocked. Unlocked bootloader is a reason to be alert.
2. TestM: Xiaomi’s iron diagnostics service (available only for authorized service centers, but leaks can be found online).

Please note the serial numbers of the components: AIDA64 Check out the Device section → Sensors. If the battery, screen and motherboard serials don't match the production date, the device was assembled from different donors. It's also useful to check the history of Wi-Fi connections: c Settings → Wi-Fi → Additionally. → The history of the network should not be suspicious access points (e.g, repair_shop_123).

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If thermal-engine errors occur in adb logcat logs, this indicates problems with the cooling system - the device may have overheated in the past.

FAQ: Frequent questions about Xiaomi vetting