Fairphone 6 unbrick: Trapped in fastboot mode with locked bootloader and corrupted stock ROM

[Extarion]

Looks like I might have some good news to share, at the very least for those who haven’t bricked their phone yet.

With today’s release of FP6.QREL.15.105.0 (SPL June 2025), I felt confident enough to attempt to flash Fairphone Android from /e/OS 3.0.2 (Official, SPL May 2025), and did so with success!

Mind you, I am no expert on this matter, so proceed at your own risk.

I followed Fairphone’s instructions on unlocking the bootloader and manually installing Android.

@AnotherElk

When in fastboot mode, run the command fastboot flashing get_unlock_ability before attempting to relock the bootloader.
Don’t relock the bootloader if the result of the command is 0!

As warned, the bootloader was left unlocked after booting into Android, with fastboot flashing get_unlock_ability returning 0 in Fastboot. So I did some minor research into the issue as it occurred for the Fairphone 4, which is when I found these comments:

Can't flash stock FP4 ROM

Definitely check fastboot flashing get_unlock_ability immediately before locking. And don’t boot into Android after flashing it, the first boot resets it to 0 (The reason being that’s how you get your phone delivered and there are apps that check for that). Flash → Check → Lock

Can't flash stock FP4 ROM

Yeah, just flash it again You can lock critical, but there’s no access to the critical partitions if the bootloader is locked so you don’t gain any security advantage. Not sure if there are apps that check for that If you are worried something might not work, lock it, that’s how it’s supposed to be on stock.

So I returned to Fastboot, reflashed the phone with the recently installed Android release, and held the “Volume Down” during boot – preventing it from booting into Android and instead returning to Fastboot.

Now, fastboot flashing get_unlock_ability returned 1, so I was able to relock the bootloader according to the official instructions, making sure that the phone never fully booted into Android between each step, instead loading back into Fastboot and retesting fastboot flashing get_unlock_ability before proceeding.

And… that’s that. I am now back on Android and have not encountered any quirks so far.

All the kudos and big thanks to @AnotherElk and @hirnsushi for being the giants upon whose shoulders I could stand.