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How to Root Lenovo S850: Full Guide

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How to Root Lenovo S850: Full Guide

Rooting your Lenovo S850 gives you full administrative control over the Android operating system, allowing you to remove bloatware, install specialized apps, overclock the CPU, and customize the system in ways that are otherwise impossible. This guide walks you through the entire process, from unlocking the bootloader to installing a custom recovery and finally rooting the device. Before you begin, understand that rooting voids your warranty and carries a small risk of bricking your phone if steps are not followed carefully. Make sure your battery is charged above 70% and back up all important data.

What You’ll Need

  • Lenovo S850 with USB debugging enabled (Settings > Developer Options > USB Debugging)
  • A Windows PC with internet access
  • USB cable compatible with the S850
  • Lenovo USB drivers installed on your PC
  • ADB and Fastboot tools (download the platform-tools from the official Android developer site)
  • Unlocked bootloader (instructions provided in Step 1)
  • A custom recovery image (TWRP or CWM) for the Lenovo S850
  • SuperSU or Magisk ZIP file for installation

Step-by-Step

  1. Back up your device. Use the built-in backup or a third-party app to save contacts, photos, and other important files to your PC or cloud storage. Rooting will wipe your phone, so this step is critical.
  2. Enable Developer Options and USB Debugging. Go to Settings > About Phone and tap “Build Number� seven times until you see “You are now a developer.� Then go to Settings > Developer Options and enable USB Debugging.
  3. Install the Lenovo USB drivers. Download the official Lenovo USB driver package for the S850 and install it on your PC. Reboot your PC if prompted.
  4. Set up ADB and Fastboot. Extract the platform-tools ZIP to a folder on your PC (e.g., C:\adb). Open a command prompt in that folder (Shift+Right-click > “Open command window here�).
  5. Unlock the bootloader. This is the most critical step. On the Lenovo S850, bootloader unlocking is not officially supported, so you must use a third-party method. One common method involves using a special tool called “Lenovo S850 Bootloader Unlocker� (search for it on XDA Developers). Follow the tool’s instructions carefully. Typically, you’ll put the phone into fastboot mode (turn off, then press and hold Volume Down + Power), connect to PC, and run the unlock command. This will wipe your phone.
  6. Install a custom recovery. After unlocking, boot into fastboot mode again. Download a TWRP image for the Lenovo S850 (ensure it matches your device model). In the command prompt, type: fastboot flash recovery twrp.img (replace “twrp.img� with the actual filename). Then run fastboot reboot.
  7. Boot into recovery. Turn off the phone. Press and hold Volume Up + Power to boot into recovery mode. You should see the TWRP interface.
  8. Flash the root package. Download the SuperSU ZIP (or Magisk ZIP) and copy it to your phone’s internal storage (or an SD card). In TWRP, tap “Install,� select the ZIP file, and swipe to confirm the flash.
  9. Wipe cache and reboot. After flashing, go to “Wipe� > “Advanced� and wipe the Dalvik Cache and Cache. Then reboot the system.
  10. Verify root. Once the phone boots (first boot may take longer), install a root checker app from the Play Store to confirm root access.

Common Mistakes

  • Skipping the backup. Unlocking the bootloader wipes all data. Without a backup, you lose everything.
  • Using the wrong recovery image. Flashing a recovery meant for another Lenovo model can brick your phone. Always verify the exact model number (S850) and the variant (e.g., S850t).
  • Not enabling USB debugging. ADB commands will fail if USB debugging is off.
  • Interrupting the flash process. Unplugging the USB cable or closing the command window during flashing can permanently damage the bootloader.
  • Ignoring battery level. A low battery during flashing can cause a power loss and brick the device.

Tips

  • Use a USB port directly on your PC motherboard (not a front panel or hub) to avoid connection drops.
  • Keep the command prompt window open until the process is completely finished.
  • After rooting, install a root management app like SuperSU or Magisk Manager to control which apps get root access.
  • If you plan to install custom ROMs later, make a full Nandroid backup from TWRP before proceeding.
  • Read the XDA Developers forum thread for your specific device to get the latest tools and community support.

Troubleshooting

  • ADB not recognizing the device: Reinstall USB drivers, try a different cable, and ensure USB Debugging is enabled. Also, check Device Manager for any yellow exclamation marks.
  • Fastboot command hangs: Make sure you are in fastboot mode (the screen should show “FASTBOOTâ€� or “fastboot modeâ€�). If not, try holding Volume Down + Power for 10 seconds.
  • Bootloader unlock fails: The tool may not support your exact firmware version. Check for an updated version or try the manual fastboot command: fastboot oem unlock.
  • Phone stuck in boot loop after rooting: Boot into recovery (Volume Up + Power), wipe cache and Dalvik cache, then reboot. If still stuck, reflash the SuperSU ZIP.
  • Root checker says no root: Ensure you flashed the correct ZIP for your Android version (e.g., SuperSU for Android 5.0+). Try flashing again, or use Magisk instead.
  • Phone won’t boot at all: If it’s completely unresponsive, try holding the power button for 20 seconds to force restart. If that fails, you may need to restore the stock firmware using SP Flash Tool (search for your device’s stock ROM).

Frequently Asked Questions

Does rooting void my warranty?

Yes, rooting typically voids the manufacturer’s warranty. However, you can often unroot and restore the stock firmware to regain warranty coverage, but this is not guaranteed.

Will rooting delete my data?

Unlocking the bootloader will wipe all data on your phone. The rooting process itself (flashing SuperSU) does not erase data, but it’s recommended to back up before starting.

Can I still receive OTA updates after rooting?

Usually not. OTA updates may fail or cause issues because the system partition has been modified. You’ll need to manually flash updates or use custom ROMs.

Is rooting safe?

If you follow the steps correctly, the risk is low. However, there is always a chance of bricking your device if you flash the wrong files or interrupt the process. Stick to trusted sources and verify file compatibility.

What is the difference between SuperSU and Magisk?

SuperSU is a traditional root manager that modifies the system partition. Magisk is a systemless root that keeps the system partition untouched, allowing you to hide root from apps and pass SafetyNet in some cases. Magisk is generally recommended for newer Android versions.

Can I unroot after rooting?

Yes. You can unroot by removing the root manager app and restoring the stock boot image, or by flashing the original firmware. For Magisk, you can use the “Uninstall� option in the Magisk Manager app.

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