[ZenFone 2 Q&A, Help & Troubleshooting] remidem:
Impossible to update with sdcard

Thank you for your reply. I tried OTA update with sdcard:

1) In Settings/About/Software information, my current version is 2.13.40

2) I dowloaded, from http://xdaforums.com/zenfone2/general/ota-links-stock-rom-t3093999 update from 2.13 to 2.14

3) Copied to external sd, in root folder, and renamed zip to MOFD_SDCARD.zip

4) Rebooted in recovery

5) Update failed. Here is my log:

Finding update package...

I:Update location: /sdcard/MOFD_SDUPDATE.zip

Opening update package...

E:file path:/sdcard/MOFD_SDUPDATE.zip

Installing update...

script aborted: Package expects build fingerprint of asus/WW_Z00A/Z00A:5.0/LRX21V/2.13.40.13_20150401_8390_user:user/release-keys or asus/WW_Z00A/Z00A:5.0/LRX21V/2.14.40.19_20150415_9660_user:user/release-keys; this device has asus/WW_Z00A/Z00A:5.0/LRX21V/2.18.40.12_20150529_9543_user:user/release-keys.

Package expects build fingerprint of asus/WW_Z00A/Z00A:5.0/LRX21V/2.13.40.13_20150401_8390_user:user/release-keys or asus/WW_Z00A/Z00A:5.0/LRX21V/2.14.40.19_20150415_9660_user:user/release-keys; this device has asus/WW_Z00A/Z00A:5.0/LRX21V/2.18.40.12_2015

E:Error in /sdcard/MOFD_SDUPDATE.zip

(Status 7)

SD Installation aborted.

This is because the version of system.img is 2.18 and the fimware version is 2.13.

Indeed I have 2 choices:

- override system with a system.img in version 2.13, but I cannot find any.

- try to apply OTA update 2.17 to 2.18 or 2.18 to 2.19 but it seems risky.

Finally I found!!! I think that a version of the firmware is tagged in system partition and another version (classically the same) is tagged in data partition (this is the one you see in Parameters -> About -> Firmware version). When I wanted to flash a firmware the same version as the one written in parameters (2.13), my phone refused to downgrade because the version of system was higher (2.18). So I had to format the system partition, apply update with official 2.18 firmware. And it worked! My phone was unrooted and I could apply method 3 root.

My issue occurred because I made the following:

1) bought a phone with a 2.13 firware

2) used it for months, applied OTA updates until 2.18

3) flashed a 2.18 pre-rooted system.img

4) used it for weeks until a made an update of supersu

5) my phone couldn't boot any more, so I wiped data (I could avoid that, if I knew!). It made a factory reset, ie get back firmware to 2.13, but system was still in 2.18

Here is the procedure to revert a phone flashed with a pre-rooted system.img (to sell it, send back to warranty, or root with another method):

1) Download official firmware from asus website in the same or higher version of your pre-rooted system.img. Do not rely on version in Parameters -> About -> Firmware version. Or simply download the latest version.

2) In your phone bootloader, enter the following commands with your PC:

fastboot erase system (I'm not sure it is necessary)

fastboot format system

3) With your phone, go into recovery menu, then to "Update with adb"

4) With your PC, go to the directory where you downloaded the firmware as zip, and enter the following command: adb sideload nom_du_fichier_teléchargé.zip

5) It takes about an hour

6) You can reboot

After that I used method 3 to root again, so that I can now OTA update exactly the same way I used to do before rooting. Moreover, I think I can update supersu as well.