[Zenfone 5 Q&A, Help & Troubleshooting] quyvinh:
*** Please hit thank you if this is help you. I am newbie here, really need more thank you from all of you.

Let me go more details for this problem. OK, YOU NEED TO DOWNGRADE YOUR FIRMWARE BACK TO 1.14.40.50 in order to flash the WW firmware. Also please prepare ADB and fastboot tools, and you need a little knowledge about command line (DOS). So of course this will be done in Windows. Also intel and Asus driver ready.

The original link was in Vietnamese. I am just translating this into English, and modified a little bit to make it more sense.

Driver: http://www.mediafire.com/download/arg2pkaum0yyp2w/Asus_Zenfone_driver.zip

Original post: http://www.tinhte.vn/threads/huong-...enfone-5-khi-da-up-len-fw-1-15-40-35.2330710/

*** Step 1: Some notes you need to do before you process: the phone must be rooted, turn on "Developer options/USB debugging".

*** Step 2: download 2 roms of version 1.14.40.50. Say if your phone is CN (if phone is TW, download TW), and you want to flash to WW

CN: http://dlcdnet.asus.com/pub/ASUS/ZenFone/A500CG/UL_ASUS_T00F_CN_1_14_40_50_user.zip

WW: http://dlcdnet.asus.com/pub/ASUS/ZenFone/A500CG/UL_ASUS_T00F_WW_1_14_40_50_user.zip

Now, inside each of these 2 zip files, there is another zip file, please extract that zip file of each above downloaded rom. You should see this

UL-ASUS_T00F-CN-1.14.40.50-user.zip

UL-ASUS_T00F-WW-1.14.40.50-user.zip

Very important: your phone is CN, then go inside the UL-ASUS_T00F-CN-1.14.40.50-user.zip, find and copy the 4 files: fastboot.img, boot.img, recovery-from-boot.p and install-recovery.sh into your ADB folder. Again, these 4 files must be from the 1.14.40.50 of CN rom.

*** Step 3: open NOTEPAD for install-recovery.sh (Do not use anything other than BINARY editor, not MS WORD, not Wordpad, ...) find and change the line " /system /recovery-from-boot.p " to " /data/local/tmp/recovery-from-boot.p ". Rmember, all should be in 1 LINE only when open in NOTEPAD

*** Step 4 moved here (actually should be step 4 after the step 3 above): copy 2 files recovery-from-boot.p and install-recovery.sh (modified) to root folder " /data/local/tmp". this is why you need to root your phone first.

*** Step 5: run into the Droidboot, by power off the phone, then hold the Power button and Volume UP button (should hold the power button first, the instanly hold the volume up button, when the screen on, release the power button but still hold the volume up)

*** Step 6: in Windows, open command prompt with Admin right (START\run\cmd or Windows button + R to open run, then type cmd). GO to ADB folder, check device by typing " fastboot devices ". You should see some thing without error. Or if nothing show, then your device is not recognized. check driver again. Now asume your phone is now connected, type the following 2 lines:

fastboot flash fastboot fastboot.img (look phone screen, should say successfully)

fastboot flash boot boot.img (look phone screen, should say successfully)

Now reboot your phone and boot normally to android system.

*** Step 7: after booting, back to your windows computer, still in CMD screen, in folder ADB\ type:

adb shell (hit Enter)

su (hit Enter)

sh data/local/tmp/install-recovery.sh (hit Enter)

*** Step 8: almost done. Now you are still on the 1.15 CN firmware. You are OK to downgrade CN 1.14 firmware. Turn off Wifi, turn off Data. You need to install the 1.14 CN ROM first, before you can change to anything else. Copy " UL-ASUS_T00F-CN-1.14.40.50-user.zip " (not the original dowloaded, but the zip file inside it, look at the file name) to INTERNAL SDCard STORAGE (not ROOT folder, not MICRO-SDCARD folder either). Since you are turn off the WIFI, DATA, you should see on the notification, the firmware is ready to be upgrade. Do it. If for some how you can not see it, then do the firmware through ADB (power off, go into recovery by power on + volume down, then release power button while hold the volume down, then still hold the volume down and now press volume up), check device by type "ADB devices " if you see sideload then it means you are ready. Now type "adb sideload UL-ASUS_T00F-CN-1.14.40.50-user.zip" or for easier, you can change the rom name to rom_CN.zip and "adb sideload rom_CN.zip"

after finished, Restart the phone. Still wifi off, Data off.

*** Step 9: change the region. Since you downloaded the 1.14 WW, now repeat step 8 for 1.14 WW (by renaming the file, replace WW by CN). After all, go to setting / about / upgrade and TURN OFF the upgrade notification. DO NOT ever upgrade to 1.15 again, I recommend waiting until the CUSTOM Recovery coming out so we can back up and restore the firmware. Remember, your device SKU is still CN, this would never be changed. Flash WW does not mean you change your device SKU. Your phone device SKU now should be showed WW (check it by enter the droidboot, on the top left screen). So in the future, you can upgrade to WW directly without changing CN to WW.

***BTW, the root will be lost. go ahead and re-root your phone again if you want.