Xiaomi marriage checklist: full checklist 2026 for smartphones, watches and gadgets

Buying Xiaomi equipment is always a lottery: even in official stores, you get devices with factory defects. According to service centers, up to 12% of smartphones and 8% of smart watches of this brand return in the first 2 weeks due to a hidden marriage.

This article is a step-by-step algorithm for checking any Xiaomi gadget (from Redmi Note 13 Pro+ to Mi Band 8) for marriage before payment. We will analyze unique tests for Chinese versions of devices (which are often sold as “global”), learn how to detect component swapping and show which defects Xiaomi considers “normal” and does not repair under warranty. All methods are tested on devices from 2022-2026 and are relevant to models with MIUI 14/15 and HyperOS.

1.External inspection: 7 signs of marriage that sellers hide

Start with a visual inspection, which will take 5 minutes, but will help to identify up to 40% of defects. Examine the device in bright light (preferably in the sun or under a 5000K lamp).

• 🔍 The gaps between the case and the screen: Xiaomi allow backup 0.3 Um, but if you can see the gap with the naked eye, it's a build defect. IP53/IP68 (for example, Xiaomi 14 Ultra).
• 🎨 Uneven body color: on glossy models (Redmi Note 12 Pro) there are often paint stains or spots under the film.
• 📱 Screen curvature: Put your smartphone down on a flat surface, and if the corners or center play when you press it, it's a defect in the adhesive layer that will eventually detach the display.
• 🔋 Battery bloating: swipe your finger over the back cover. If you feel a bulge (even 0.5 mm), the battery has already degraded.

⚠️ Note: On Xiaomi devices with AMOLED-screens (e.g., screens, POCO F6 Pro) allows a light wave at the edges of the display, which is a feature of the technology, not a defect, but if the wave is visible against a gray background, it is a backlight defect.

Screen check: tests for broken pixels and matrix defects

The screen is the most expensive component in a smartphone, and its defects are often masked. Use 4 tests to check:

1. Monochrome fillers: Open this site and turn on the red, green, blue, black and white screens sequentially: 🖥️ Broken pixels (dots of a different color). 🌑 Backlight in black (up to 5% brightness is allowed, if more - a defect). 🔴 Yellow spots on a white background (sign of polarizer detachment).

Burnout test.

AMOLED

Xiaomi 13T

POCO X6 Pro

Touch test

Touch Screen Test

Google Play

⚠️ Attention: On devices with LTPO-screens (Xiaomi 14, Mix Fold 3) when testing for black color can be observed slight flickering - this is normal operation of adaptive frequency technology.

Run monochrome tests (red/green/blue)

Check the black screen for backlight (in a dark room)

Test the sensor for uniformity of response

Look at the screen at the angle of burnout (for AMOLED)

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Diagnostics of the battery: how to identify the "killed" battery in 3 minutes

The battery is the second most common source of problems in Xiaomi, and even a new device can have a battery with reduced capacity due to long storage in stock.

1. Code ##4636##: Enter it in the dialer, go to Battery Information. Level must match the percentage in the status bar, Status must be Good. If status is Bad or Unknown, battery is defective.
2. Temperature check: During charging, the battery temperature should not exceed 40°C (checked by AIDA64 or AccuBattery).

For deep diagnostics, use the Camera MX app (it has a Sensor Test tool that shows the real sensor resolution). For example, if the Redmi Note 12 Pro with a declared 50 MP, the application shows 48 MP, this is normal (the firmware cuts the edges), but if less than 45 MP, the sensor is defective.

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To check the night mode, take a picture of the dark corner of the room with the lights off. A serviceable Xiaomi 13/14 camera should show details, not solid noise.

5.Iron Check: How to Identify Processor, Memory, and Module Problems

A hidden iron defect does not appear immediately, but it can render the device unusable in a month.

1. CPU stress test: install the Throttling Test CPU from Play Market. Run the test for 15 minutes. If performance drops by more than 20%, it's a sign of trottling (overheating or chip defect).
2. Memory Check: In AIDA64, look at the Memory section. If the internal memory shows less than the declared volume (for example, 119 GB instead of 128 GB), this is a defect of the controller.
3. Test of speakers and microphones: 🔊 Turn on music at maximum volume – there should be no wheezing or difference in sound between the top and bottom speakers. 🎤 Record your voice on a tape recorder from 1 meter away. If you hear interference or a muffled sound, the microphone is defective.

Sensor diagnostics

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Error

⚠️ Note: On devices with Snapdragon processors 8 Gen 2/3 (Xiaomi 14, POCO F5 Pro) heat is allowed to 48°C when loaded, but if the phone is switched off from overheating (even when it is under load) 50°C) is a defect of the cooling system.

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If AIDA64 specifies Revision in the CPU section: Unknown is a sign of a fake processor (relevant to used devices from China).

6. Hidden defects: what is checked in service centers, but not told to customers

There are problems that you can’t see with standard tests, but they show up after 1-3 months. Xiaomi service centers check them only under warranty, but you can identify them yourself:

• 📶 Antenna Test: Enter ##4636## → Network information. If the signal 4G/5G leaping between -110 dB -80 dBm (even in a good coverage area) – a problem with soldered antenna contacts.
• 🔄 Type-C connector check: connect the charger and swing the cable in different directions. If charging is interrupted, the connector is poorly soldered (a frequent problem of Redmi). 10/11 series).
• 🛡️ Water test: even if the device has protection IP68, Check the moisture indicators (small white dots in the tray) SIM If they're red, the gadget has been in contact with water.
• 🔋 Charging cycles: In AccuBattery, look at the number of cycles. For a new device, it should be 0-5. If it's more than 20, the battery is already worn out.

⚠️ Note: In Xiaomi devices with infrared port (Redmi Note 12, POCO X5) It is common to have an IR sensor that only works from close range (less than 1 meter) and can be checked by trying to operate the air conditioner from different distances.

7. Check firmware and region: how not to buy the "Chinese" version under the guise of global

Many sellers are selling devices for the Chinese market (CN ROM) Global (Global) ROM). This is fraught with problems with Google Services, updates and work SIM-How to distinguish the maps:

1. Code ##44336##: will show the firmware version. If the name has CN, China or ING, it's the Chinese version.

⚠️ Warning: Some sellers are reflashing Chinese devices to Global ROM, This does not solve the problem with the modem (Chinese versions often do not support European frequencies). 5G). You can check the support on the FrequencyCheck website.

Checklist before buying: what to do if you found a marriage

If you find a defect, follow the algorithm:

⚠️ Note: If you buy a device from AliExpress, JD.ru or other foreign stores, it will be more difficult to return it. Use a dispute in the payment system (for example, in PayPal or a bank) and attach proof of marriage (photos, videos, screenshots of tests).

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If the seller agrees to a replacement, demand a new device from a different batch - often a marriage occurs in whole batches (for example, the Redmi Note 11 Pro 2022 had a microphone problem).

FAQ: Frequent questions about marriage in Xiaomi