FP3+ - bad boot

Help Fairphone 3
1

Hi everyone, I’d like to ask for some help.
I bought a second-hand FP3 phone, which, when switched on, indicated that the bootloader was unlocked, but after a short while the Google Android system booted up on the phone.
I switched to developer mode and locked it using the ‘fastboot oem lock’ command. The phone restarted, and it worked fine on the next restart, but then I got the following error message:
“Your device is corrupt. It can’t be trusted and will not boot. Visit this link: g.co/ABH”

I went through the cross-check questions with ChatGPT, and this was the message it produced as the final result:
“Fairphone 3 FP3
Bootloader 6.A.039
fastboot:
Device unlocked: false
Device critical unlocked: true
get_unlock_ability: 0
Error:
Your device is corrupt.
It can’t be trusted and will not boot
fastboot flash:
Partition flashing is not allowed”

If I’m interpreting this correctly – and ChatGPT also said as much – I can restore the phone, but I’ll need official assistance to do so.
Can you help?

I look forward to your reply – my youngest daughter can’t wait to start using her phone :smiley:

Thank you.

2

No not with a FP3

So did you already try to unlock the bootloader?

If this doesnt work see here

Or here

3

Hi everyone! Thanks for your reply – I’ve had a look. In the meantime, I’ve installed a stock Google Android system on another FP3 phone instead of Ubuntu Touch.
I’ll get round to this phone in due course, and I’ll read through it in detail then.
Thanks for your time.

4

Mostly depend on the “allow OEM unlock” in the “developer options”

In the relocking sequence, you must start by relocking critical before relocking bootloader.

Here i advise to unlock if possible, to be able to reinstall latest FairphoneOS version as a sane base

5

to be able to lock it, while there is no real advantage to lock critical when the bootloader is locked as far as I know.

6

You can force an unlock of the device using fastboot: