How to Unbrick and Restore OnePlus One to Cyanogen OS 12 Stock Firmware [Fastboot Method]
The much awaited Cyanogen OS 12 for OnePlus One was released earlier today through an OTA update and the flashable zip file is available as well. Since then a lot of OPO users are looking to update their device to CM12 which one can update easily by installing the update manually using stock recovery. The process isn’t straight forward if one wants to update to CM 12 from Oxygen OS. Unfortunately, several OPO users have bricked their device some or other way while trying to update it. In case, you’ve bricked OnePlus One or it’s stuck in a boot loop then our guide below will help you bring back your lovable phone back to alive state.
This process allows you to flash the official Cyanogen OS 12 (based on Android 5.0.2 Lollipop) factory image on OnePlus One and restore it back to factory state. The guide is pretty easy and doesn’t requires using any commands or a toolkit. A simple script will let you automatically flash the stock firmware on OnePlus One in a few minutes. If you’ve a custom recovery installed or your phone is rooted then that will be switched to default state as well.
Note: This process will WIPE entire data on your phone, including the data on internal storage. Before proceeding, make sure your phone is charged and you’ve taken a backup of your important data such as photos, media, files, etc.
Guide to Flash CM12 Factory Image on OnePlus One in Windows –
1. Download OnePlus One CM12 factory image “cm-12.0-YNG1TAS0YL-bacon-signed-fastboot.zip” (fastboot flashable package).
2. Download and install Universal ADB Driver for Windows.
3. Extract the contents of the fastboot.zip package to a folder.
4. Download the flashing tools package. It contains Fastboot & ADB files.
5. Extract the contents of “cm-12.0-YNG1TAS0YL-bacon-signed-fastboot.zip” file into the above extracted factory image folder. It should look like this:
6. Boot OnePlus into fastboot mode – To do so, power off the phone. Then press the Power and Volume UP key simultaneously. The phone should show “Fastboot Mode” screen as shown below.
7. Connect the phone to PC via USB cable.
8. Now Run the flash-all.bat file by double-clicking on it.
9. A command window will open up and flashing procedure will start. (Do Not disconnect the device during flashing)
10. After installation is done, the CMD window will close automatically.
11. Disconnect the USB cable, and boot the phone normally by long pressing the Power button.
That’s it! You have restored OnePlus One to the official and latest Cyanogen OS 12 ROM.
Points to be noted:
- Flashing over fastboot is possible on locked bootloaders as these are officially signed images.
- Flashing won’t change the lock/unlock status of your bootloader. It will remain locked/unlocked like before.