How to Root Zenfone 6 Firmware 2.21.40.39

Since RootZenfoneV3 Can't Root Zenfone 6 with 2.21.40.39 Firmware Version, so i made this tutorial.

1. Download recovery.img from 2.21.40.29 Firmware You can download HERE, or Mirror Here or you can extract it from 2.21.40.29 firmware
2. ADB Fastboot Tool If you don't have it (Download Here)
3. Flash recovery.img
- Go to Fastboot (Turn off Device and Press Power+Volume Down)
- Connect to PC/Laptop
- Open ADB Folder, Shift+Right Click > Open Command Here
- Type fastboot flash fastboot recovery.img
- Wait Until Finish and Reboot
4.  Root with RootZenfoneKitkat, Tutorial Here

[Full Firmware] Zenfone 6 A600CG T00G V2.21.40.39

How to OTA update ? (Go to settings>About>System Update>Check for Update)
How to update Manual ? Here
How to update via ADB sideload ? Here 

ZENFONE 6  firmware: 
WW VERSION
Version V2.21.40.39(WW)

Description

ASUS ZenFone 6(T00G/) software Image: V2.21.40.39 for WW SKU only* Improvement Item: 1.Update phone APN version to 81. 2.Update per Facebook sharing policy 3.Due to changes in Facebook’s service policy, ASUS apps will no longer be able to access the list of all your Facebook friends or their public information such as birthdays, feeds, public albums, and etc. Some features have been modified in order to comply with this new policy. Thank you for your understanding. Changes on the apps: ASUS Gallery  Friends’ public albums are no longer in service.  Likes and comments feature are disabled. ASUS Contacts  Friends’ recent feeds push notification are disabled.  Lower resolution profile picture is used.  Option to set contact’s cover image from Facebook is removed.  Synchronization of birthday information is not supported. Phone In-call screen  Lower resolution profile picture is used. 5. Improve ystem stability For more information please refer to: WW：http://www.asus.com/zentalk/ReleaseNotes Steps of Update: 1. Check software version of your device** 2. Download device software and Update SOP (From “Manual” Item) 3. Only apply to same SKU update, Example: WW->WW, CN->CN, TW->TW. 4. Software update cannot transfer the software SKU and downgrade the software version. 5. Wrong SKU may cause update failure, please update the same SKU version only. *How to know the device model? Path: Settings->About-> Model number Example: ASUS_T00I **How to know the device software version? Path: Settings->About-> software information->Build number ***System upgrade may cause part of data missing, please buckup your important data before system upgrading.

File Size	753,42 (MBytes) 2015.02.04  update
Download from	Global

ZENFONE 6  firmware: 
TW VERSION
Version V2.21.40.39(TW)

Description

ASUS ZenFone 6(T00G/) software Image: V2.21.40.39 for TW SKU only* Improvement Item: 1.Update phone APN version to 81. 2.Update per Facebook sharing policy 3.Due to changes in Facebook’s service policy, ASUS apps will no longer be able to access the list of all your Facebook friends or their public information such as birthdays, feeds, public albums, and etc. Some features have been modified in order to comply with this new policy. Thank you for your understanding. Changes on the apps: ASUS Gallery  Friends’ public albums are no longer in service.  Likes and comments feature are disabled. ASUS Contacts  Friends’ recent feeds push notification are disabled.  Lower resolution profile picture is used.  Option to set contact’s cover image from Facebook is removed.  Synchronization of birthday information is not supported. Phone In-call screen  Lower resolution profile picture is used. 5. Improve ystem stability For more information please refer to: TW：http://www.asus.com/zentalk/tw/ReleaseNotes Steps of Update: 1. Check software version of your device** 2. Download device software and Update SOP (From “Manual” Item) 3. Only apply to same SKU update, Example: WW->WW, CN->CN, TW->TW. 4. Software update cannot transfer the software SKU and downgrade the software version. 5. Wrong SKU may cause update failure, please update the same SKU version only. *How to know the device model? Path: Settings->About-> Model number Example: ASUS_T00I **How to know the device software version? Path: Settings->About-> software information->Build number ***System upgrade may cause part of data missing, please buckup your important data before system upgrading.

File Size	755,73 (MBytes) 2015.01.29  update
Download from	Global

Asus Zenfone 4 5 6 RAW Firmware for ASUS Flashtool

Asus Flashtool Interface

Today, Asus Zenfone Blog will share RAW firmware (all WW) for Zenfone Series. With this RAW Firmware you can Flash your Zenfone 4/Zenfone 5/Zenfone 6 With AFT (Asus Flash Tool).

If  You Reupload these links please let me know by comment box so i can add some mirror links if these links goes down/deleted. 

How to Use Asus Flash tool can you Read in This Post

Asus Zenfone 4 .RAW

Another Link:

Mirror  1 (mediafire, thx to Tim en )

Asus Zenfone 5 .RAW

Another Link:

Mirror  1 (mediafire, thx to Tim en )

 

 

Asus Zenfone 6 .RAW

Another Link:

Mirror  1 (mediafire, thx to Tim en )

[Full Firmware] Zenfone 6 A600CG T00G V2.21.40.29

How to OTA update ? (Go to settings>About>System Update>Check for Update)
How to update Manual ? Here
How to update via ADB sideload ? Here 

ZENFONE 6  firmware: 
WW VERSION
Version V2.21.40.29(WW)

Description

【Version】 2.21.40.29 20141208 【Model Name】 A600CG / A601CG 【Release Date】 2014/12/17 【Release Note 】 Enhanced GPS performance. Fixed SD card related issue caused by third party apps. Improved the device compatibility with Bluetooth selfie remote controller. 【Key New  functions】 Gallery Operation sequence changed for MicroFilm: MicroFilm has been isolated from Gallery and acts as a new standalone mobile app called ASUS MicroFilm, it still can be launched directly from Gallery.  You can select the photos from Gallery and send them to MicroFilm App via tapping the MicroFilm  button or Auto MicroFilm to make exciting videos ! Add three new Crop ratio sizes: 3:2, 2:3, and 16:9. ASUS MicroFilm The brand new ASUS MicroFilm app allows you to make stunning slideshow videos in just 3 steps; promptly make your memories go round. 3 steps: Select your favorite photos Apply a pro-designed  movie theme Share it on the social clouds PhotoFrame widget Add four brand new photo frames, including thin photo frame with white color, frameless, normal glass photo frame and thin glass photo frame. Camera Add more options to support camera shutter control, including Bluetooth remote controllers or Bluetooth earphones. ASUS Backup Easily back up or restore ASUS ZenUI Apps in ZenFone and other ASUS mobile devices Save/restore call logs and personal settings, ie. weather location, alarms, browser preferences, etc. Save or restore data of your favorite Apps. Settings Add “ASUS ZenUI APP Updates” interface in Setting for user to update AUSU ZenUI apps easier and faster. Enhance the power management interface in Setting. Browser Supported auto hiding title bar for those devices with screen size smaller than or equal to 6 inches. Added menu item “Close other tabs” for quickly closing unused tabs. Improved Traditional Chinese (Hong Kong) translations. Improve browser stability. Calculator Add percentage (%) calculation in simple calculation mode and advanced engineering mode. Add Clear function in simple calculation mode and advanced engineering mode. Add 00 button in advanced engineering mode. Re-layout simple calculation mode and advanced engineering mode. Quick Setting Add screenshot tool in Quick settings. Lockscreen Add “Skip Slide Lock” option when turning on the security lock

File Size	731,38 (MBytes) update 2014/12/08
Download from	Global

ZENFONE 6  firmware: 
TW VERSION
Version V2.21.40.29(TW)

Description

【Version】 2.21.40.29 20141208 【Model Name】 A600CG / A601CG 【Release Date】 2014/12/17 【Release Note 】 Enhanced GPS performance. Fixed SD card related issue caused by third party apps. Improved the device compatibility with Bluetooth selfie remote controller. 【Key New  functions】 Gallery Operation sequence changed for MicroFilm: MicroFilm has been isolated from Gallery and acts as a new standalone mobile app called ASUS MicroFilm, it still can be launched directly from Gallery.  You can select the photos from Gallery and send them to MicroFilm App via tapping the MicroFilm  button or Auto MicroFilm to make exciting videos ! Add three new Crop ratio sizes: 3:2, 2:3, and 16:9. ASUS MicroFilm The brand new ASUS MicroFilm app allows you to make stunning slideshow videos in just 3 steps; promptly make your memories go round. 3 steps: Select your favorite photos Apply a pro-designed  movie theme Share it on the social clouds PhotoFrame widget Add four brand new photo frames, including thin photo frame with white color, frameless, normal glass photo frame and thin glass photo frame. Camera Add more options to support camera shutter control, including Bluetooth remote controllers or Bluetooth earphones. ASUS Backup Easily back up or restore ASUS ZenUI Apps in ZenFone and other ASUS mobile devices Save/restore call logs and personal settings, ie. weather location, alarms, browser preferences, etc. Save or restore data of your favorite Apps. Settings Add “ASUS ZenUI APP Updates” interface in Setting for user to update AUSU ZenUI apps easier and faster. Enhance the power management interface in Setting. Browser Supported auto hiding title bar for those devices with screen size smaller than or equal to 6 inches. Added menu item “Close other tabs” for quickly closing unused tabs. Improved Traditional Chinese (Hong Kong) translations. Improve browser stability. Calculator Add percentage (%) calculation in simple calculation mode and advanced engineering mode. Add Clear function in simple calculation mode and advanced engineering mode. Add 00 button in advanced engineering mode. Re-layout simple calculation mode and advanced engineering mode. Quick Setting Add screenshot tool in Quick settings. Lockscreen Add “Skip Slide Lock” option when turning on the security lock

File Size	751,38 (MBytes) update 2014/12/08
Download from	Global

Open ART Mode on Zenfone 6 and Zenfone 5

DWYOR
Do It With Your Own Risks
=====================================================================
Need Rooted Device
=====================================================================

ART is a new Android runtime being introduced experimentally in the 4.4 release. This is a preview of work in progress in KitKat that can be turned on in Settings > developer options but ASUS currently add Limitation to ART mode in Zenfone, so we can't found ART mode on Developer Options.

Today i will teach you how to Open ART Mode On Zenfone 5/6. Tested on Zenfone 6.

Requirements:

• Rooted Device
• Root Explorer / ES File Explorer / Another
• Zenfone with Android 4.4.2

Instructions:

1. Make sure your zenfone already have root permission.
2. Have Root Explorer / ES File Explorer

   

   I use ES FE

   
   

3.   Open ES FE
   


4.  Change Root Folder Permission to RW
   


5. open build.prop (/Root/System) (you can backup your original build.prop first by copy it to SD card)
   
   
   

   

   Open With ES Text Editor



6. Find Line persist.sys.dalvik.vm.lib = libdvm.so and Replace libdvm.so to libart.so

   

   Edited to libart.so



7. Reboot Device (The First booting Takes 10-20 minutes so be patient)
   

How to Unbrick Zenfone 5 and Zenfone 6

If you can enter Recovery when at USB logo by press Volume up + Power Use this Tutorial (HERE-How to Unbrick Your Zenfone)

If you can't enter Recovery at USB mode, you can try this Method:

Zenfone Brick USB Mode

Resources to Download:

1. Intel USB Driver (Download HERE)
2. Asus USB Driver (Download HERE) 
3. iSocUSB-Driver-Setup-1.0.4.exe (Download HERE)
4. xfstk-downloader-setup-1.5.1.exe (Download HERE)
5. IntelAndroidDrvSetup1.5.0.exe (Download HERE)
6. ADB Fastboot (Flashtool.zip) (Download HERE)
7. FW DnX, IFWI, OS DnX, OS Image files (Download For Zenfone 5 / Download for Zenfone 6)
8. Update Splashscreen.bat (Download HERE)
9. ASUS Zenfone5/6 Firmware/ROM (Download HERE) 

Instructions:

1. Download All Resources above and Place it to one Folder, and Install Intel USB Driver& ASUS Zenfone USB Driver.
2. The first step is to install iSocUSB-Driver-Setup-1.0.4.exe, when your phone is on USB pattern appears when connected to the computer should be two new devices, both at Intel Soc classification: CloverviewPlus Device and Intel Soc USB Driver.

   

   unbrick-zenfone-device manager

3.  The second step is to install xfstk-downloader-setup-1.5.1.exe and switch to the CLVP A0/B0/B1 Tab, and Make sure Device status column which shows the Scanning: CLOVERVIEWPLUS TARGETS DETECTED: 1, if the final surface is displayed as 0, check again Device Manager and make sure Zenfone is detected.
   

    

   xfstk-downloader zenfone

   Detected Device: 

   

   CLOVERVIEWPLUS TARGETS DETECTED: 1

4. The next thing is very simple, sequentially select FW DnX, IFWI, OS DnX, OS Image files that you have downloaded earlier.and Click Begin Download, then USB pattern on the phone will have a progress bar display (red) 

   

   Unbrick Zenfone xSTFK Downloader Progress

5. Upon completion of the phone will automatically reboot, if the boot screen becomes the pattern of Intel inside, there are two ways:
   a. Enter Recovery and Flash ROM via ADB
   b.  Via Fastboot flash the splashscreen
   - phone into fastboot mode and connected to your computer, click on the execution  Update_SplashScreen.bat
6. If the above steps are completed, the phone still will not turn on, or in the recovery Flash factory ROM also has problems (occurring failed to mount / cache errors ), here there is a last resort:
   - Download The Reset.bat  (Download HERE)
   - Phone into fastboot mode and connected to your computer, click on the execution Reset.bat re-initialize the phone.
   -Go to Fastboot, Flash Recovery (Tutorial HERE) and Flash ROM with the same build number with the recovery (Tutorial HERE)

Another way to Un-brick Using Asus Flash Tool

DWYOR (Do it With Your Own Risks)
Thanks to Shakalaca for the Knowledge and Resources

How to Manually Update to Kitkat Zenfone 5/6 Without Error

Zenfone Kitkat

Before Update to Kitkat:

• Make sure no disabled/freeze/deleted apps for stock apps from asus
• If you have already made modifications please revert back to original firmware (How? Here)

Resources to Download: (Kitkat/4.4.2 Version is V2.19)

• Download Recovery img for Kitkat (Download for Zenfone 5/Download for Zenfone 6),(Mirror Zenfone 5 / Mirror Zenfone 6) password : www.asus-zenfone.com, based on your firmware version (WW/TW/CHT)
  
• Download Zenfone 5/6 Kitkat ROM (Make sure your download version is the same with recovery version above) (Kitkat ROM for Zenfone 5 / Kitkat ROM for Zenfone 6)
• ADB Driver 
• Intel USB Driver

Instructions:

1. Download ADB and Extract it, Download Intel Driver and Install
2. Download Recovery 
3. Download Zenfone Firmware 
4. Copy recovery img to ADB Folder and Copy .zip firmware to ADB folder too (make sure you extract the firmware first then copy to adb folder).
5. Activate USB Debugging on Your Zenfone and Connect it to PC/Laptop via USB Cable (How to Activate USB Debugging? HERE)
6. Open CMD at ADB Folder by Hold Shift+Right Click and Open Command Window Here
7. Type this on Command Window: adb reboot bootloader and wait until your zenfone enter fastboot mode
   
8. When succeed enter fastboot then flash recovery, at Command Prompt type: fastboot flash recovery <filename.img> and wait until finish
   
   
9. Choose Recovery, when android robot appear press volume down+volume up and choose update from ADB. Now Flash the firmware via ADB, by type ADB sideload <firmwarename.zip>
   
10.  Wipe Data and Reboot

[Download] KitKat 4.4.2 Firmware/ROM Asus Zenfone 4 5 and 6

How to OTA update ? (Go to settings>About>System Update>Check for Update)
How to update Manual ? Here
How to update via ADB sideload ? Here 

ZENFONE 5  firmware: 
WW VERSION
Version V2.19.40.6(WW)

Description

ASUS ZenFone 5(T00F/T00J) software Image: V2.19.40.6 for WW SKU only* Note: Please make sure update software version V1.18.40.10 first before update to software version V2.19.40.6 Improvement Item: 1. System update to Android 4.4 2. Improved Miracast compatibility 3. Added support for DLNA protocol 4. Fix Russian translation Key New functions: 1. Do Not Disturb mode 2. Call Guard(applies to models sold in China and Taiwan only) 3. Full dual standby with two SIM cards(applies to dual SIM models only) 4. Filter effects for videos 5. Reply via Call-in SIM card, system will auto select the right phone Steps of Update: 1. Check software version of your device** 2. Download device software and Update SOP (From “Manual” Item) 3. Only apply to same SKU update, Example: WW->WW, CN->CN, TW->TW, CHT->CHT. 4. Software update cannot transfer the software SKU and downgrade the software version. 5. Wrong SKU may cause update failure, please update the same SKU version only. *How to know the device model? Path: Settings->About-> Model number **How to know the device software version? Path: Settings->About-> software information->Build number ***System upgrade may cause part of data missing, please buckup your important data before system upgrading.

File Size	707,49 MBytes update 2014/10/03
Download from	Global

TW VERSION
Version V2.19.40.6(TW)

Description

ASUS ZenFone 5(T00F/T00J) software Image: V2.19.40.6 for TW SKU only* Note: Please make sure update software version V1.18.40.10 first before update to software version V2.19.40.6 Improvement Item: 1. System update to Android 4.4 2. Improved Miracast compatibility 3. Added support for DLNA protocol 4. Fix Russian translation Key New functions: 1. Do Not Disturb mode 2. Call Guard(applies to models sold in China and Taiwan only) 3. Full dual standby with two SIM cards(applies to dual SIM models only) 4. Filter effects for videos 5. Reply via Call-in SIM card, system will auto select the right phone Steps of Update: 1. Check software version of your device** 2. Download device software and Update SOP (From “Manual” Item) 3. Only apply to same SKU update, Example: WW->WW, CN->CN, TW->TW, CHT->CHT. 4. Software update cannot transfer the software SKU and downgrade the software version. 5. Wrong SKU may cause update failure, please update the same SKU version only. *How to know the device model? Path: Settings->About-> Model number **How to know the device software version? Path: Settings->About-> software information->Build number ***System upgrade may cause part of data missing, please buckup your important data before system upgrading.

File Size	741,02 MBytes update 2014/10/01
Download from	Global

CHT VERSION
Version V2.19.40.6(CHT)

Description

ASUS ZenFone 5(T00F/T00J) software Image: V2.19.40.6 for CHT SKU only* Improvement Item: 1. System update to Android 4.4 2. Improved Miracast compatibility 3. Added support for DLNA protocol 4. Fix Russian translation Key New functions: 1. Do Not Disturb mode 2. Call Guard(applies to models sold in China and Taiwan only) 3. Full dual standby with two SIM cards(applies to dual SIM models only) 4. Filter effects for videos 5. Reply via Call-in SIM card, system will auto select the right phone Steps of Update: 1. Check software version of your device** 2. Download device software and Update SOP (From “Manual” Item) 3. Only apply to same SKU update, Example: WW->WW, CN->CN, TW->TW, CHT->CHT. 4. Software update cannot transfer the software SKU and downgrade the software version. 5. Wrong SKU may cause update failure, please update the same SKU version only. *How to know the device model? Path: Settings->About-> Model number **How to know the device software version? Path: Settings->About-> software information->Build number ***System upgrade may cause part of data missing, please buckup your important data before system upgrading.

File Size	741,02 MBytes update 2014/10/01
Download from	Global

WW Version 
FOTA files (Place to Internal Folder/via ADB Sideload) Manual OTA files (not full firmware) #Zenfone5 WW
1.18.40.9 to 1.18.40.10 : 20MB
http://fota.asus.com/delta_package/phone/WW_a500cg/formal/WW_user_1.18.40.9_20140827_0215-user-WW_a500cg-WW_user_1.18.40.10_20140903_9870-user-WW_a500cg-20140925_r/WW_500_0827_0903_20140925_r.zip

1.18.40.10 to 2.19.40.6 (Kitkat) : 442MB
http://fota.asus.com/delta_package/phone/WW_a500cg/formal/WW_user_1.18.40.10_20140903_9870-user-WW_a500cg-WW_user_2.19.40.6_20140927_8163-user-WW_a500cg-20140929/WW_500_0903_0927_20140929.zip

CN Version *soon

ZENFONE 4  firmware: 

 Version CHT_6.5.24(4.4)

Description

ASUS ZenFone4(T00I) software Image: V6.5.24 (Android 4.4) for CHT SKU only* Improvement Item:1.System upgrade to KitKat 4.4 2.Call Guard 3.Filter effects for videos 4.Reply via Call-in SIM card, system will auto select the right phone number via the call 5.Full dual standby with two SIM cards (applies to dual SIM models only) 6.Do Not Disturb modeSteps of Update: 1.Check software version of your device** 2.Download device software and Update SOP (From “Manual” Item) 3.Only apply to same SKU update, Example: WW->WW, CN->CN, TW->TW. 4.Software update cannot transfer the software SKU and downgrade the software version. 5.Wrong SKU may cause update failure, please update the same SKU version only. *How to know the device model? Path: Settings->About-> Model number Example: ASUS_T00I **How to know the device software version? Path: Settings->About-> software information->Build number ***System upgrade may cause part of data missing, please buckup your important data before system upgrading.

File Size	849,92 MBytes update 2014/10/01
Download from	Global

 VersionWW _6.5.27(4.4)

Description

ASUS ZenFone4(T00I) software Image: V6.5.27 (Android 4.4) for WW SKU only* Improvement Item:1.System upgrade to KitKat 4.4 2.Call Guard 3.Filter effects for videos 4.Reply via Call-in SIM card, system will auto select the right phone number via the call 5.Full dual standby with two SIM cards (applies to dual SIM models only) 6.Do Not Disturb modeSteps of Update: 1.Check software version of your device** 2.Download device software and Update SOP (From “Manual” Item) 3.Only apply to same SKU update, Example: WW->WW, CN->CN, TW->TW. 4.Software update cannot transfer the software SKU and downgrade the software version. 5.Wrong SKU may cause update failure, please update the same SKU version only. *How to know the device model? Path: Settings->About-> Model number Example: ASUS_T00I **How to know the device software version? Path: Settings->About-> software information->Build number ***System upgrade may cause part of data missing, please buckup your important data before system upgrading.

File Size	849,92 MBytes update 2014/10/03
Download from	Global

ZENFONE 6  firmware: 
WW VERSION
Version V2.19.40.15(WW)

Description

ASUS ZenFone 6(T00G) software Image: V2.19.40.15 for WW SKU only* Note: Please make sure update software version V1.18.40.10 first before update to software version V2.19.40.15 Improvement Item: 1. System update to Android 4.4 2. Improved Miracast compatibility 3. Added support for DLNA protocol 4. Fix Russian translation Key New functions: 1. Do Not Disturb mode 2. Call Guard(applies to models sold in China and Taiwan only) 3. Full dual standby with two SIM cards(applies to dual SIM models only) 4. Filter effects for videos 5. Reply via Call-in SIM card, system will auto select the right phone Steps of Update: 1. Check software version of your device** 2. Download device software and Update SOP (From “Manual” Item) 3. Only apply to same SKU update, Example: WW->WW, CN->CN, TW->TW, CHT->CHT. 4. Software update cannot transfer the software SKU and downgrade the software version. 5. Wrong SKU may cause update failure, please update the same SKU version only. *How to know the device model? Path: Settings->About-> Model number **How to know the device software version? Path: Settings->About-> software information->Build number ***System upgrade may cause part of data missing, please buckup your important data before system upgrading.

File Size	711,87 MBytes update 2014/10/03
Download from	Global

TW VERSION
Version V2.19.40.13(TW)

Description

ASUS ZenFone 6(T00G) software Image: V2.19.40.13 for TW SKU only* Note: Please make sure update software version V1.18.40.10 first before update to software version V2.19.40.6 Improvement Item: 1. System update to Android 4.4 2. Improved Miracast compatibility 3. Added support for DLNA protocol 4. Fix Russian translation Key New functions: 1. Do Not Disturb mode 2. Call Guard(applies to models sold in China and Taiwan only) 3. Full dual standby with two SIM cards(applies to dual SIM models only) 4. Filter effects for videos 5. Reply via Call-in SIM card, system will auto select the right phone Steps of Update: 1. Check software version of your device** 2. Download device software and Update SOP (From “Manual” Item) 3. Only apply to same SKU update, Example: WW->WW, CN->CN, TW->TW, CHT->CHT. 4. Software update cannot transfer the software SKU and downgrade the software version. 5. Wrong SKU may cause update failure, please update the same SKU version only. *How to know the device model? Path: Settings->About-> Model number **How to know the device software version? Path: Settings->About-> software information->Build number ***System upgrade may cause part of data missing, please buckup your important data before system upgrading.

File Size	741,02 MBytes update 2014/10/01
Download from	Global

WW Version
FOTA files (Place to Internal Folder/via ADB Sideload) Manual OTA files (not full firmware) #Zenfone6 WW
1.18.40.11 to 1.18.40.12 :
http://fota.asus.com/delta_package/phone/WW_a600cg/formal/WW_user_1.18.40.11_20140901_8156-user-WW_a600cg-WW_user_1.18.40.12_20140903_2744-user-WW_a600cg-20140925_r/WW_600_0901_0903_20140925_r.zip

1.18.40.12 to 2.19.40.15(kitkat):
http://fota.asus.com/delta_package/phone/WW_a600cg/formal/WW_user_1.18.40.12_20140903_2744-user-WW_a600cg-WW_user_2.19.40.15_20140927_4873-user-WW_a600cg-20140929/WW_600_0903_0927_20140929.zip