How to check the display on your Xiaomi phone: from broken pixels to the sensor

The screen is not just the face of the device, but the most vulnerable part, and according to statistics from service centers, 68% of Xiaomi breakdowns are associated with damage to the display, from microcracks to complete failure of the matrix. 3 in 10 users are unaware of hidden screen defects until they interfere with work, such as dead pixels on the screen. AMOLED-Redmi Note 12 Pro matrices+ They can remain invisible for months until they start to grow into clusters.

The problem is that most Xiaomi owners only check the display after a fall or obvious artifacts, and meanwhile, early diagnosis saves up to 70% of the cost of repairs — for example, replacing the protective glass instead of the entire matrix or using a warranty. In this article, we will discuss 7 professional methods of inspection that are used by service center engineers, but adapted for home use, you will learn how to identify not only obvious cracks, but also hidden backlight defects, sensor problems or color distortions — all without special equipment.

We will pay special attention to models with AMOLED-screens (Mi 11 Ultra, Xiaomi) 13T, POCO F5), where defects are manifested differently than on IPS-matrices (Redmi) 10C, POCO M5). Also consider which tests are useless for modern smartphones (for example, checking by eye in bright sun) and why.

Why it is important to check the display regularly

Many users mistakenly believe that the display should only be diagnosed after mechanical damage.In fact, Xiaomi screens are prone to degradation even when used carefully.

1. Natural wear of the matrix. AMOLED-screens (installed in Xiaomi) 12 Pro, Redmi K50) lose 15% brightness 2 year of operation due to burnout of organic LEDs. IPS-matrixes suffer from the "memory effect" - when static interface elements (for example, the navigation panel) leave traces. 3-4 The month helps to track the dynamics of deterioration.

2. Hidden manufacturing defects. Even new smartphones can have broken pixels, uneven lighting or sensor problems. POCO X5 Pro 2023 revealed up to 0.3% of the greenish-colored matrix defect at low brightness, and the warranty covers such cases only with official diagnostics — and it is performed on the same tests that you can do at home.

3. Resale value impact: A smartphone with a perfect display in the secondary market is on the market 20-30% Xiaomi customers often check screens with special applications (we will discuss them below) – if you identify problems in advance, you can honestly indicate them in the ad or fix them in advance.

⚠️ Note: If you plan to sell Xiaomi via Avito or Yulu, be sure to take screenshots of the display tests (especially checks for broken pixels).This will protect you from accusations of concealment of defects - such disputes account for 12% of all complaints in the secondary market.

Method 1: Visual inspection – what and how to look

Start with a basic exam, and this method doesn't require any tools, but it can detect up to 40 percent of the obvious defects.

• 🔍 Cracks and chips. Check not only the front but also the ends of the screen - often cracks start at the edge and "spread" under the protective glass. On Xiaomi with curved screens (Mi 11 Ultra), inspect the side faces at an angle.
• 🎨 Divorces and stains. IPS-Matrices (Redmi Note 11) often show yellowish spots when heated (defect of the adhesive layer). AMOLED Look for greenish or purple divorces – this is a sign of polar filter detachment.
• 💡 Backlight: Turn on a white background (such as notes) and look at the screen at an angle of 45.°. Uneven lighting ("clouding") is characteristic of Redmi 9A and POCO M3 — It is not critical, but it reduces reading comfort.
• 🖱️ Touch layer. Swipe your finger around the edges of the screen — if you feel "steps" or roughness, it can be detachment of the sensor (a common problem after changing the glass in informal services).

Professional life hack: To detect microcracks that are not visible in normal light, point a flashlight at a sharp angle on the screen that is turned off. The cracks will reflect light like thin silver lines, a method used in service centers for preliminary diagnosis.

Method 2: Test for broken pixels - Step-by-step instructions

Broken pixels are dots on a screen that don't change color or that burn in the same color all the time. AMOLED-matrices (Xiaomi 13, POCO F4 GT) They appear as bright colored dots, on IPS (Redmi 10 is black. Single bit pixels are not critical, but if there are more than 5 on the screen, it is a reason to replace under warranty.

To verify:

1. Install the Dead Pixel Test app (available on Google Play) or use the online service.
2. Run the test for pure colors (red, green, blue, black, white).
3. Look carefully at the screen from a distance. 20-30 See: Broken pixels will contrast with the background.
4. For AMOLED-Check the screens against a gray background (50% brightness) – so you can see the “stuck” subpixels better.

Critical information: On the screens of Xiaomi 12T Pro and Redmi. K60 technologically AMOLED 2K Broken pixels can migrate – if you notice a new defect, don’t delay diagnosis.In 2023, Xiaomi recognized this defect as a manufacturing defect and extended the warranty to 24 months.

Set brightness to 100%|Turn off autobrightness|Remove the protective film (if any)|Check in the dark room.-->

Method 3: Testing the sensor layer - exact methods

A faulty sensor is one of the most insidious problems. It can work "over and over," not respond to touches in certain areas, or give false positives (POCO F5 from 120Hz, Redmi Note 12 Pro+ 144Hz) sensor defects are often masked as interface lag.

For diagnosis:

• 📱 Built-in test. Go to Settings. → The phone. → All specifications → Equipment test (on some models, the path may be different). Select Touch Screen Test and follow the instructions.
• 🎯 Draw lines, circles and dots all over the screen – the program will show missed touches or “ghost” presses.
• 🔄 Multi-touch test. Open this site in your browser. At the same time, tap the screen. 5-10 fingers – all points should be displayed without delay.

Typical sensor problems on Xiaomi:

• 🔴 Insensitivity zones at the edges – often after glass replacement in informal services (characteristic of Redmi 9 and Redmi). POCO M4 Pro).
• 🔵 "Ghost" touches - the screen itself reacts to the pressing, as if someone is touching it. culprit: damaged plume or moisture (relevant to Xiaomi 11 Lite) NE).

⚠️ Note: If the sensor stops working after the update MIUI, Don't rush your phone to the service. First, reset your settings through Settings. → System system → Additionally. → Resetting by selecting only settings (without deleting data) solves a problem related to software conflicts in 30% of cases.

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If the sensor is not working well in games (for example, in the PUBG Mobile or Genshin Impact, but the tests are fine, try disabling Improved Response in the developer settings. On some Xiaomi models, it conflicts with the high refresh rate of the screen.

Method 4: Diagnostics of color reproduction and contrast

Distorted color reproduction is a common problem that many users blame on "matrix features." Meanwhile, the **wrong colors may indicate:

• GPU problems (Adreno in Snapdragon or Mali in Mediatek)
• Display plume defect (often after falls)
• burnout AMOLED-Matrixes (characteristic of smartphones older than 2 years).

To verify:

1. Open the Lagom test LCD — It will show how your screen transmits gradients, gray shades and colors.
2. Compare the results with the reference images: 🟤 Greenish tint on white background - a sign of a cheap matrix (found in Redmi) 10A and POCO C40). 🔴 Red shift in dark colors is typical for AMOLED-burnout. 🔵 Blue artifacts at the edges - a defect of the polarization filter.

AMOLED

memory

Norms for Xiaomi:

• 📱 IPS-screens (Redmi Note 11, POCO M5): allow a slight yellowish tint at the angle of view >60°.
• 📱 AMOLED (Xiaomi 13, Redmi K60): normal contrast - 1:1,000,000, with a value below 1:500,000, the matrix is worn out.
• 📱 E4 AMOLED (POCO F5 Pro: Must transmit 100% color space DCIP3.

Method 5: Checking the illumination and uniformity of the glow

Uneven lighting (backlight bleed) - a scourge IPS-On Xiaomi, it manifests as light spots in the corners or grayish haze in dark scenes. For example, in the Redmi Note 10 Pro, 18% of users faced this problem due to savings on backlight LEDs.

How to check:

1. Turn on a black background (for example, by opening the keyboard in a dark theme).
2. Set the brightness to 50% - at maximum illumination defects are less noticeable.
3. Look at the screen from an angle. 30-45°. Pay attention to this: 🔦 Light spots in the corners - typical for Redmi 9 and POCO X3 NFC. 🌫️ Gray haze at the edges - defect of the diffuser (Redmi Note) 8 Pro). 💡 Yellow divorces - a sign of overheating of the matrix or adhesive layer.

What to do if you find a defect:

• 📉 If the backlight is uneven but does not interfere with use, it is not critical".
• 🔧 If the spots are pronounced (seen in daylight) - contact the service. AMOLED-In the screens, this may be a sign of layers being detached.
• 🔄 In the models with IPS (Redmi 10) sometimes helps flashing - the defect may be due to incorrect operation of the backlight driver.

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Uneven lighting on the IPS-The manufacturers (including Xiaomi) allow deviations of up to 15% of the uniform glow, the main thing is that the defect does not impair the visibility of the content.

Method 6: Test for artifacts in scrolling and animation

Dynamic artifacts are distortions that only show up when the image moves: stripes, flickering, tears in the image.

• problems with the graphics processor,
• defect in the display plume,
• Firmware conflict (especially after updates).

How to identify:

1. Open any website with a long page (like Wikipedia) and scroll up and down quickly.
2. Start a video with a high frame rate (60) FPS) on YouTube and enable scrolling comments.
3. Use a flicker test – it will show how the screen copes with a quick change of frames.

Typical artifacts on Xiaomi:

• 🔴 Horizontal stripes when scrolling - a defect of the plume or matrix (often after falls).

⚠️ Note: On smartphones with LTPO AMOLED (Xiaomi 13 Ultra, Redmi K60 Pro) scroll flickering may be related to adaptive refresh rates. Try fixing it to 60 Hz or 120 Hz in the screen settings.

Method 7: Checking with an Engineering Menu

The engineering menu (#4636##) provides detailed information about the display, but it requires caution - incorrect settings can cause malfunctions.

1. Open the Engineering Menu and select Hardware Testing → Display.
2. Run the tests: 🎛️ Color Test – check color reproduction at the driver level. 📊 Gray Scale - Gray gradation test (detects broken subpixels). 🔄 Flicker Test – Diagnostics of flicker (relevant to the AMOLED).

MIPIDSI

Warning: Do not change the parameters in the engineering menu unless you are sure of their purpose! For example, changing the value of Max Brightness can lead to overheating of the matrix.

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If the engineering menu does not open by code, try installing the app. MTK Engineering Mode (for smartphones on Mediatek) or Qualcomm EngineerMode (for Snapdragon).

FAQ: Answers to Frequent Questions