Have you turned on your smartphone, but instead of the usual full-screen image you only see left or right half of the display, the second part is black, blurry or displays a mirror copy? This problem occurs on devices Samsung Galaxy, Xiaomi Redmi, Honor and other brands run Android —from budget models to flagships. The reasons may lie in both software failures (for example, after a system update) and hardware malfunctions (damage to the cable or matrix).

In 80% of cases, the problem can be solved without contacting the service center - just reset the screen settings, disable split modes or reboot the device in safe mode. But if half the screen turns black after the phone was dropped or got wet, it will most likely require repair. In this article we will analyze all possible causes and ways to eliminate the defectincluding hidden functions Androidthat are not written about in the official instructions.

1. Reboot and check in safe mode

The first thing to do is restart the device. This helps in 30% of cases, especially if the problem occurred after installing an application or updating the system. Press and hold the power button, then select Reboot (on some models - Restart). If after a reboot the screen returned to normal display, the reason was a temporary failure of the graphics driver.

If the reboot did not help, check the screen operation in safe mode. This mode disables all third-party applications, allowing you to identify a software conflict:

  1. Hold down the power button until the shutdown menu appears.
  2. Press and hold the item Turn off (or Turn off power).
  3. Confirm entering safe mode (on some devices you will need to enter a PIN).

In safe mode, there will be an inscription at the bottom of the screen Safe Mode or Safe ModeIf half of the screen is working normally. - one of the installed applications is to blame. Remove recently added apps or reset the settings (more on this below).

📊 How often do you have problems with the screen on Android?
Never
Rarely (once every year)
Sometimes (every six months)
Often (monthly)

2. Disabling split screen mode (Multi-Window)

Many users accidentally activate split screen mode (called Multi-Window or Split Screen), which makes it seem as if half the display is not working. This mode allows you to open two applications at the same time, but sometimes it works spontaneously - for example, when swiping from top to bottom or clicking on an application icon in the multitasking panel.

To turn off splitting:

  • 📱 On Samsung: Swipe down from the top edge of the screen, then swipe down along the gray line between the windows or tap on the three dots (⋮) → Close split.
  • 📱 On Xiaomi/Redmi/POCO: swipe up from the bottom edge and hold, then drag the dividing line to the edge of the screen.
  • 📱 On Google Pixel and stock Android: tap on the dividing line between the windows and select Exit split mode.

If the screen is split but the dividing line is not visible (for example, due to a crash), try Force close all applications:

Settings → Applications → [Three dots] → Show system ones → [Select the last used application] → Stop
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On some firmware (for example, MIUI), split screen mode can be disabled via Settings → Accessibility → Split mode screen (turn off the slider).

3. Resetting screen and scaling settings

Incorrect settings scaling or screen resolution can lead to cropping of the image. For example, if the developer settings enable Minimum width with a non-standard value or the mode for for visually impaired people, you can return the default settings as follows:

  1. Open Settings → System → Gestures → Screen scale (name may vary).
  2. Select Reset or move the slider to the middle position.
  3. If the problem persists, check Settings → Accessibility → Font and display size — install Default.

On devices Samsung Additionally check:

  • 🔍 Settings → Screen → Screen resolution — select the maximum (for example, FHD+ or WQHD+).
  • 🔍 Settings → Additional functions → With one hand - disable if enabled.

Screen scale reset|Resolution set to maximum|One-handed mode disabled|Accessibility returned to standard-->

4. Check for hardware damage

If half of the screen completely black (without backlight) displays artifacts (color bars, flickering) or reacts to touches with delay, the problem is most likely hardware. Common reasons:

  • 💥 Damage to the cable - after a fall or impact, the contacts between the motherboard and the screen are broken.
  • 💧 Moisture ingress —oxidation of contacts leads to partial loss of signal.
  • 🔥 Overheating or manufacturing defect —matrix defect (often found on AMOLEDscreens).

Do a quick test:

  1. Connect the phone to a computer or TV via HDMI (or USB-C → HDMI adapter If the image on the external screen is full, the matrix or adapter is at fault). cable.
  2. Call the device. If during a call the backlight of the black half of the screen lights up, the problem is in the graphics driver, not in the hardware.
How to check the cable without disassembling?

Press the phone body in the area next to the volume buttons (where the cable connects) with the board). If, when pressed, the image blinks or is restored, the cable is damaged and requires replacement.

⚠️ Attention: If the screen responds to touches only in one half (for example, the right side does not press), do not try to “develop” it by force. This may worsen matrix damage. Contact the service to diagnose the sensor.

5. Reset to factory settings

If software methods did not help, but you are sure that the problem is not hardware, perform Full reset. This will delete all data, so first make a backup copy (via Settings → Google → Backup or manually).

Instructions for resetting:

  1. Open Settings → System → Reset settings (to Xiaomi: Settings → About phone → Reset settings).
  2. Select Delete all data (factory reset).
  3. Enter the PIN or pattern, confirm the action.

If the phone does not respond to touches (due to the non-working half of the screen), reset the settings via recovery mode:

  1. Turn off the device.
  2. Hold Power button + Volume up (on some models - Volume down).
  3. V menu Recovery select Wipe data/factory reset (use volume buttons to navigate, power button to confirm).
⚠️ Attention: On devices with an unlocked bootloader (bootloader), resetting may lead to locking. FRP (reset protection). To avoid this, unlink your account before resetting Google in the settings.

6. Updating or rolling back the firmware

Sometimes half of the screen stops working after Android updates - especially on devices with unofficial firmware (for example, LineageOS or Pixel Experience). In this case, rolling back to the previous version or installing fresh firmware will help.

How to update the firmware:

  • 📲 Through settings: Settings → System → Software update → Download and install.
  • 📲 Manually: download the firmware for your model from the official website (Samsung — Samsung Members, Xiaomi — MIUI Downloads) and install via Recovery.

To roll back the firmware:

  1. Find an archive with a previous version of the software (for example, on the forum 4PDA or XDA Developers).
  2. Copy the file to the memory card.
  3. Load into Recovery and select Apply update from SD card.
Brand Method updates Official source of firmware
Samsung Via Samsung Members or Smart Switch https://www.samsung.com/ru/support/
Xiaomi/Redmi/POCO Via Settings → About phone → MIUI update https://new.c.mi.com/global/miuidownload/index
Google Pixel Via Settings → System → Software update https://developers.google.com/android/ota
Honor/Huawei Via HiSuite or Support App https://consumer.huawei.com/ru/support/
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If after the update half of the screen turns black, and rolling back does not help, the problem may be incompatibility of the firmware with yours model. Check the version Build number in the settings (Settings → About the phone) and compare with the supported firmware on the official website.

7. data-i="199">If none of the methods helped, and half of the screen still does not work, the reason is most likely

If none of the methods helped, and half of the screen still does not work, the reason is most likely physical damage. Here are the signs for which you should contact the service:

  • 🔧 Black half of the screen not highlighted even with bright lighting.
  • 🔧 Visible on the screen colored vertical stripes or "broken" pixels.
  • 🔧 Phone overheating in the screen area.
  • 🔧 The problem appeared after fall, impact or contact with water.

The cost of repair depends on the model and type of damage:

  • 💰 Replacement of the cable: from 1,500 to 4,000 ₽.
  • 💰 Matrix replacement: from 3,000 to 15,000 ₽ (on AMOLEDscreens are more expensive).
  • 💰 Repair after moisture: from 2,500 to 8,000 ₽ (includes cleaning and soldering contacts).
⚠️ Attention: On devices with OLEDscreens (for example, Samsung Galaxy S/A-series, Google Pixel), a defect in half the screen is often associated with matrix burnout. In this case, replacing the screen is inevitable, and attempts at software repair will only aggravate the problem.

FAQ: Frequently asked questions about half the screen on Android

Can a virus cause a problem with half the screen?

Theoretically yes, but extremely unlikely. Viruses usually do not affect hardware display, but can change scaling settings or run background processes that overload the GPU. Check your device with an antivirus (for example Malwarebytes or Dr.Web) and remove suspicious applications.

Half of the screen only works in some applications. What's the matter?

This is a sign application conflict with screen resolution. Update the problematic application or clear its cache (Settings → Applications → [Name] → Memory → Clear cache). If this is a system application (for example Launcher), try changing the shell (set Nova Launcher or Action Launcher).

After replacing the screen, half of it doesn’t work again. What should I do?

Probably, the master used non-original matrix or connected the cable incorrectly. Contact another service with a request to check:

  • Compatibility of the installed matrix with the phone model.
  • The quality of soldering of the cable (sometimes the contacts come off after assembly).
  • Settings EDID (screen identifier) in the service menu.
A mirror image is displayed on half the screen. How to fix it?

This is a failure in the settings displays for external displays. Try:

  1. Disable Miracast or Wireless Display in settings (Settings → Connected devices → Connect to display).
  2. Reset the screen settings (see section 3).
  3. If the problem persists, flash the device using SP Flash Tool (for Mediatek) or Odin (for Samsung).
Is it possible to replace the screen cable yourself?

Technically yes, but without experience. The cables on modern smartphones are fragile, and their replacement requires: risky no experience. The cables on modern smartphones are fragile, and their replacement requires:

  • Special tools (suction cup, plastic mediator, tweezers).
  • Knowledge of the connection diagram (on some models the cables go through the motherboard).
  • Soldering station (if the contacts are oxidized).

If you are not sure, it is better to contact the service The cost of an error (damage to the matrix or board) may. exceed the cost of repair.