[ZenFone 2 General] SomeOne181:
I am less than even a novice experienced on smartphones resoft as I was not interested till a week ago. My objective is to transform, instead trowing to garbage, and what costs 500 euro just years ago, used Asus ZF in a very low 1 W/h server for old games or http/ftp server and so. So nothing more. I was looking to format the storage in any way, as I am not aware at this point what custom bootloaded modified the storage when Wipe command was executed. Also it is still unclear for me how resoft with xfstk is working as this was not actually designed for the smartphones. if I am not wrong.

It looks for me that you are mixing the restore files and I will adice to do not do so unless you are doing experiments with purpose as how I did. For example with 550ML files I have after flash instead a 4 color flag, a screen half grey half white but yet no bootloader. Also it looks for me that your phone react better at 551ML files, so ensure what model you have. Yet if it is 551 and not 550, ensure that you are using right files.

I will advice to :

- ensure you are using right booloader restore files based your model. Again do not mix it between versions. Use precise version combination for each try. There are 3 of it. 2 for FW and 1 for OS, and each have it's one section in xFSTK.

- start xFSTK and select files for each section as described by community members. Ensure GP flag is set as mentioned previous, and also ensure that you set proper timeout too. Yet 60 seconds should be enough anyway, but I set it 600. Press Begin Download.

- set computer volume to acceptable level to hear when phone connection will be detected. You may also open Device Manager and check section for USB interface been detected. Remember that this will be always just seconds connected for each stage for firmware and OS to be downloaded.

- now connect the phone to USB cable while it is stopped. If it do not start automatically, long press power button till double regular start vibration is present. Release power button. In some cases, after I flashed other ZF fw and os phone may not vibrate as confirmation that it starts, but yet it starts anyway.

- now computer and xFSTK too will detect connection with the phone and you will hear the confirmation from Windows too. Yet in some cases you will see either just blank screen either usb download logo, and also just sometimes to reach to see the red progress bad in usb logo, because the download looks to be very short time. For FW it take 2-5 seconds, and for OS it takes about 5-15 seconds. This will be FW downlaod first and after that xFSTK will restart phone with a message like "continuing with OS..". Then after OS download too, it will be restarted again and xFSTK will confirm flash done and will restart phone second time while stop download after that.

- then you should see that phone start way should behave as regular double vibration start, but check result. I think if you get 4 color flag you will be close to the bootloaded restore, as I think I am. Seen that at some people 4 color flag is stay for seconds or tenths of seconds after which the bootloader starts. In my case it stay like 1-2 minutes and then phone restart in the same 4 color flag. The long power plus volume + combination will not bring something else than still 4 color flag for me. I also think that this do not work in every case because smartphones versions are very sensitive its original at firmwares versions, even if we talk about first level of device control through a software. I will be interested how community obtained droidboot_dnx.img.POS_sign.bin file for example. I cannot see it in original Asus FZ firmware archive.

- then do you have any errors in xFSTK in any of these steps ?. If yes, what will be that ?.

I do not think we can face hardbricks so far as just destroying original bootload. Yet in my case, and based my interest, I am thinking to go lower hardware level and check emmc with specific tools. Seen other sites discussion that some versions of Asus ZF's are having emms write secured and somehow not been able to write everything on it. But then I wonder why I have a successful operation in xFSTK in my case, for example.

If you think your phone battery can not handle alone without power cord, as I used to know that Asus ZF battery was just short life, been replace after only 1 year of use, you may want to open case and check its level, if you know how, you are proficient with such check, like to prevent a short-circuit, and have a multimeter. I still wonder if that will be the case as it needs just these 10-20 seconds to have the bootloader resoft, but if battery just can't handle it, then it may be that it will just not work. For example in my case I know from days ago when phone was working regularly, that battery can handle 1 hour of screen open use without problem. A new battery for Asus ZF 2 is 5-10 US$, but I think you need first to conclude if that have a problem or not.

Good luck.