Installing custom recovery, custom ROM, custom kernel and enabling root access on your Zenfone
2 are fine, but if you have not followed the instruction carefully, you
might end up with a non-booting system. This situation is called soft
bricked, which is hard to recover as it damages the bootloader.
2. However, you do not need to worry. You can unbrick a bricked Zenfone
2 (ZE550ML/ZE551ML) with a tool called xFSTK and restore stock ROM
using ASUS FlashTool.
The xFSTK tool is a windows
application that lets you restore damaged bootloader on your Zenfone 2
After restoring bootloader, you can use Asus
Flashtool to install the stock ROM.
Thanks to XDA user Sumit007s,
in this guide, we will explain how to unbrick a bricked Zenfone 2
(ZE550ML/ZE551ML) by restoring lost bootloader on it. The below method
requires little technical expertise. Read the guide carefully before
How to Restore Bootloader on Zenfone 2 (ZE550ML/ZE551ML)
Disclaimer: Follow the instruction at your own risk.
Ensure that your device is soft bricked before proceeding. We will not
be liable if any damage occurs to your device and/or its components. It
is recommended for technically talented users only.
1. Download IntelSocUSB driver [HERE] and install it on your Windows
PC. Switch off Zenfone 2, then press Power + Vol up key together few
seconds and then connect it to your computer via a USB cable.
2. Download xFSTK Downloader (v1.7) [HERE] and install it on your PC. This tool is used to restore bootloader into the memory chip.
4. Open xFSTK Downloader tool and select ‘MRD tab A0 / B0 + A0 + CRC….’ tab.
5. Click ‘Options’ and then click ‘Modify Settings’. Enable the box
‘GP Flag Override’ and set the value to 0x800000807. Click OK to
6. Click FWI DnX box and add the file dnx_fwr.bin (you have unzipped in step 3) Then, click IFWI and add the file ifwi.bin. Then click OS Image and add the bootloader file (droidboot_dnx.img.POS_sign.bin). After adding three files click ‘Begin download’ button.
[If your Zenfone restart, long press the power key to shut it down and then click power key to begin download]
7. When the process is completed, you will see ‘Success: FW+OS
download complete’ message in the tool and your phone will boot into
Now you have successfully restored bootloader on your Zenfone 2. You can now use Asus Flashtool to restore stock firmware on it. We will explain the procedure in the next post.
(Source – Sumit007s)