How to Downgrade ASUS Zenfone 2 ZE551ML/ZE550ML
Please do it carefully and DWYOR (Do it with your own risk) because wrong
move may cause the device brick.
Resources:
1. ADB Fastboot Installer (Download Here if you don't have it)
2. ZenFone 2 Original Recovery.img, bootloader.img, boot.img (ZE551ML | ZE550ML)
3. ZenFone Firmware (ZE551ML | ZE550ML) <-select OS Android and download
your firmware
How to Downgrade ASUS Zenfone 2 :
- In this tutorial I will downgrade from WW_4.21.40.112 (M) to WW_2.20.40.156 (L)
- Download ADB and Install it
- Download Recovery.img, bootloader.img, boot.img
- Download Firmware (lower version than your current version) -> I download WW_2.20.40.156 version
- Place Recovery.img, bootloader.img, boot.img to Downgrade Folder
- Go to Fastboot Mode (Turn off device and press power+volume up) or conncet the device to pc/laptop at downgrade folder press shift+right click -> open command here and type adb reboot bootloader (need usb debugging activated)
- Connect your Zenfone 2 to PC/Laptop
- Type on CMD (press enter after each line):
fastboot flash fastboot droidboot.img
fastboot flash recovery recovery.img
fastboot flash boot boot.img
- Enter recovery (Tutorial Here)
- Select Apply update from adb
- Open ZE551ML/ZE550ML firmware folder and press shift+right click > open command here
- Connect your Zenfone 2 to PC/Laptop
- Type on CMD (press enter after each line): adb sideload UL-Z00A-WW-2.20.40.156-user.zip
- Factory Reset (To avoid a crash error, but not perform factory reset is ok)
- Done
