[Asus Zenfone Go Guides, News, & Discussion] Alunduyn:
[MENTION=6461262]GioKupreishvili[/MENTION] [MENTION=7686930]Neelo[/MENTION] [MENTION=384283]taitony[/MENTION] [MENTION=1138104]Pascaleiro[/MENTION] I have solved the issue, and successfully unlocked my bootloader. I will explain how to right below. Skip to "The Solution".

The Issue :

Even if you downgrade to v36 and tick "Allow OEM Unlock", some devices might not accept the command "fastboot oem unlock". That's because newer releases locked the option, and just downgrading the ROM won't allow you to do so.

If you get

FAILED(remote:unknown command)

This post is right for you.

Also, if your phone is dead (just won't turn on, or stuck on bootloop) for any reason, scroll down to "I screwed up".

What we will do :

We are going to use SP Flash Tools to downgrade your phone even more. I don't exactly know what we are downgrading, I suppose our bootloader itself, but I might be wrong. Fact is, we will flash older versions of system partitions and I don't know how to get back to the newer ones (you should backup all your partitions, but without an unlocked bootloader I don't know how to do it, but it's probably possible. If you get img files of the partitions we will flash, do tell me!).

Note that this method also works if you screwed up your recovery (like I did, trying to flash via adb without having unlocked the bootloader)

I did this over a v36 firmware, but the kernel is for a v25. I haven't encountered issues so far, but flashing v25 might be wiser.

You might screw up your phone. It's no big deal, SP Flash Tools can always fix it up, but be sure to not be in a hurry and to not have important data on the phone before starting.

The Solution :

We will use SP Flash Tools. Proceed to download it and to get the right drivers (I used the generic device drivers bundled with adb, make sure your phone is detected with "fastboot devices"). You will also need the compiled v25 kernel (actually it's more than just the kernel, but whatever) from ASUS web page (not the source code, the only image of 1GB. Name is "Versione V12.1.0.25". Direct Link ). Inside you will find a scatter file (MT6580_Android_scatter.txt) and a ****ton of partitions.

Load the scatter, it may take some time. You will then see all the partitions you can flash.

I ticked :

preloader
lk
boot
recovery
logo
secro

However, you might not need to flash them all to succeed on this method (try flashing one by one, and keep me updated on which actually made a difference, if you would be so kind).

Flashing recovery will get you back the stock recovery if you messed up.

Turn off your phone (and make sure it really is off, waiting 10-20 secs after screen off usually is enough).

Press "Download" on SP flash tools.

Hold Volume Down on your phone and connect it.

SP Flash Tools should recognize it and start flashing.

When all is done, just get to fastboot and do "oem unlock". It should do the trick.

Note that it will wipe user data.

"I Screwed Up" :

In case you encounter issues, be it because of this method or any other, SP Flash Tools can save your phone.

If your Zenfone doesn't turn on, and seems completely dead after fastboot oem unlock (or anything else you tried on him), just get back the v25 kernel and Flash Every Partition. Start SP Flash Tools, go to the Download tab, load the scatter file, check every partition, click "Download", only now connect the phone keeping pressed power and volume down. Download should start and when it's done phone will be as new.

In case of bootloop it should also do the trick.

Note that reflashing everything will bring your phone back to 100% stock, also relocking the bootloader (I'm quite sure of this but can't confirm, correct me if I'm wrong).

If you kill your zenfone with fastboot oem unlock just start over, this time try slightly different steps (like flashing a recovery right after unlock, or reboot before, or before unlocking letting the stock firmware setup, your imagination is the limit. I did it once and can't provide a 100% safe method. Use "fastboot getvar unlocked" to check with every step if bootloader is unlocked, might help). Sooner or later you should succeed. If nothing goes right, you can always go back with SP Flash Tools.