Installation on fairphone 5 bricked phone

/e/OS Devices Fairphone
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Hi,

Today I received my fairphone 5 and I wanted to flash /e/os on it.

It had security patch 5 january 2025, so I downgraded to Fairphone OS version B.088, which has 5th November 2024. This worked, and I confirmed the security patch version.

I downloaded and installed IMG-e-2.7-t-20250111460957-official-FP5, which has that security patch verison.

Flashing went correctly.

Locking the bootloader did not: I got “Your Device Is Corrupted And Cannot Be Trusted”

Now when I boot my phone it goes to fastboot, but is locked and cannot be unlocked. fastboot flash boot boot.img didn’t work, as it is locked

Is there anything I can do?

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Stuck in a boot loop after install attempt on FP5 - #14 by aibd

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But this comment does not address the situation of the OP where I guess the following must apply “The value of rollback index can NEVER be DOWNGRADED”, from https://doc.e.foundation/devices/FP5/install

The following values control whether anti-rollback features are triggered on FP5:

  • Rollback protection errors trigger if you install an update whose version number is LESS than the rollback index’s value stored on device.
  • The value of rollback index is UPDATED to match ro.build.version.security_patch’s value of the currently installed version, but only if the bootloader is LOCKED.
  • The value of rollback index is NOT dependent on the currently installed ANDROID VERSION.
  • The value of rollback index can NEVER be DOWNGRADED.
  • Rollback protection errors are FATAL when the bootloader is LOCKED.
  • Rollback protection errors are IGNORED when the bootloader is UNLOCKED.
    Here are some examples to help you understand how anti-rollback features work: …
1 Like
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Hi,

Thanks for the replies. Read the links, and I’m not hopeful that I can fix it myself.

I think you are correct that the anti-rollback was triggered. I stupidly thought that
" * Works regardless of what version you are on. Can be used to downgrade to an older version (for example: Android 13 → Android 11)." (from https://support.fairphone.com/hc/en-us/articles/18896094650513-Install-Fairphone-OS-manually) meant I could downgrade the security patch.

Sent support a request, but they say they have a backlog of messages and will respond within 16-18 working days :frowning:

If you guys have more tips to try, I’m all ears :slight_smile:

Thanks!

1 Like
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fastboot oem allow-flashing command will allow to flash the original stock firmware even on bricked phone. You will loose all your data in the process but hey, the phone will not be a brick anymore!