ASUS Zenfone 2 Unlock Bootloader

Unofficial Step to Unlock Zenfone 2 Bootloader.

All Credit to Shakalaca, original post XDA

What is a bootloader? At its most basic level, your Android smartphone is like a hard drive, made of up several partitions. One of those partitions holds the Android system files, another holds all the app data you accumulate (which is how you're usually able to update without losing all your stuff), and others to do more behind-the scenes stuff.

Think of the bootloader as a security checkpoint for all those partitions. Because if you're able to swap out what's on those partitions, you're able to break things if you don't know what you're doing. Or, with a little hackery, you're able to run custom ROMs.

Notes:

1. Work for ZE551ML (Z00A) and ZE550ML (Z008)
2. Update firmware first to 2.19.40.12(ZE550ML) and 2.19.40.18 (ZE551ML)
3. Make sure ADB Working properly

How to Unlock Zenfone 2 Bootloader: 

1. Root your Zenfone 2 (Root) 
2. Make sure ADB is Working (Download Here if you don't have it)
3. Connect Zenfone 2 to PC and open cmd at ADB path
4. at Command Prompt Type (press enter after type each line):
adb shell
su
getprop ro.isn > /factory/asuskey
reboot bootloader
5. Phone will restart in recovery, after updating itself phone will restart and ASUS splash screen will be white.
6. Download Black Splash screen (Download)
7. navigate to adb folder opened cmd and type the following command:

adb reboot bootloader (pressed enter)
fastboot devices (pressed enter)
see if device is listed, write following

fastboot flash splashscreen splashscreen.img (pressed enter)
restart your phone and Now black splash screen is back. Congrats your bootloader is now unlocked
8. Done

PS:  you can not re-lock your bootloader again for now

Thanks again to Shakalaca

Download Official Unlock Bootloader tool for Zenfone 4 A400CG

ZENFONE 4 A400CG Unlock Bootloader Tool
Version V1.0

Description

Unlock Device App:  Unlock boot loader Notice:  1. Update your software image to Android 4.4  2. Before you download, install, and use the Unlock Device App you acknowledge and assume complete risk to the quality and performance of this App, including but not limited to the following: once you activate the App you will not be able to recover your ASUS product (“Original Product”) back to original locked conditions;the Original Product with the activated App will not be deemed the Original Product; the Revised Product will no longer be covered under the warranty of the Original Product; the software of Revised Product will no longer be deemed the software of the Original Product and can no longer receive ASUS software updates; your purchased digital content may also be affected.  You also acknowledge ASUS does not guarantee service satisfaction to any Revised Product, including events involving paid service requested by you to be performed to the Revised Product. Furthermore, such repaired Revised Product will not be covered under the warranty of the Original Product; the software of the repaired Revised Product will not be deemed the software of the Original Product and will not receive ASUS software updates. It is strongly advised that you avoid activating this App unless you fully understand and accept the risks that may arise.

File Size	360,27 KBytes                                                                            update 2014/11/27
Download from	Global

How to Re-Lock Asus Zenfone Bootloader

The trouble after unlock bootloader : Furthermore, such repaired Revised Product will not be covered under the warranty of the Original Product; the software of the repaired Revised Product will not be deemed the software of the Original Product and will not receive ASUS software updates.

But we can re-lock the bootloader

Resources:

• Intel Driver (Download Here)
• Fastboot (Download Here)  
• For a500cg/a600cg only
• Do it With your own Risk

Steps:

1. Download the Latest ROM/Firmware (V1.17.40.1X or latest version)
2. Copy if.bin from system/etc/firmware and ifwi.zip from ROM folder to Fastboot folder
   
   
   
   
   
3. Extract  ifwi.zip there will be dnx_fwr_ctp_a500cg.bin and ifwi_ctp_a500cg.bin (if zenfone 6 : dnx_fwr_ctp_a600cg.bin and ifwi_ctp_a600cg.bin
4. The phone turned into bootloader (through when adb reboot bootloader or boot while holding down the volume up+ power button) and connect to a computer through a USB cable and open cmd by press shift + right click, open comand here at fastboot folder).
5. Unlock bootloader syntax: (ZenFone 6 please dnx_fwr_ctp_a500cg.bin replace by dnx_fwr_ctp_a600cg.bin )
fastboot flash dnx dnx_fwr_ctp_a500cg.bin
fastboot flash ifwi if.bin
fastboot reboot-bootloader

6.  Re-Lock Bootloader syntax: (ZenFone 6 please dnx_fwr_ctp_a500cg.bin replace by dnx_fwr_ctp_a600cg.bin / ifwi_ctp_a500cg.bin replace by ifwi_ctp_a600cg.bin )
fastboot flash dnx dnx_fwr_ctp_a500cg.bin
fastboot flash ifwi ifwi_ctp_a500cg.bin
fastboot reboot-bootloader

How to check the phone is currently locked or unlocked?

Locked:

Unlocked:

Thanks to Shakalaca

Official Unlock Bootloader Tool Zenfone 5 & Zenfone 6

DWYOR, not tested by me
Link from asus


Zenfone 5 :
http://dlcdnet.asus.com/pub/ASUS/ZenFone/A500CG/UnLock_A500CG_a500cg_platform_rel.zip


Zenfone 6 :
http://dlcdnet.asus.com/pub/ASUS/ZenFone/A600CG/UnLock_A600CG_a600cg_platform_rel.zip

Unlock Device App: Unlock boot loader
Notice:
1. Update your software image to V1.17.40.1X or latest version
2. Before you download, install, and use the Unlock Device App you acknowledge and assume complete risk to the quality and performance of this App, including but not limited to the following: once you activate the App you will not be able to recover your ASUS product (“Original Product”) back to original locked conditions;the Original Product with the activated App will not be deemed the Original Product; the Revised Product will no longer be covered under the warranty of the Original Product; the software of Revised Product will no longer be deemed the software of the Original Product and can no longer receive ASUS software updates; your purchased digital content may also be affected.

You also acknowledge ASUS does not guarantee service satisfaction to any Revised Product, including events involving paid service requested by you to be performed to the Revised Product.
Furthermore, such repaired Revised Product will not be covered under the warranty of the Original Product; the software of the repaired Revised Product will not be deemed the software of the Original Product and will not receive ASUS software updates.
It is strongly advised that you avoid activating this App unless you fully understand and accept the risks that may arise.