Tried guide to install custom rom, am now stuck in corrupt device and 30s auto poweroff

Hello here,

After trying everything my skills allow me to, I’m seeking help here. I promise I took time to try on my own (for about 5h if I add yesterday), made some research… but nope, my device says it’s corrupt and will power off in 30s.
I still am able to access it via fastboot, but it cannot boot anymore, and I havce this “Youre device is corrupt” message. Selecting “Recovery mode” makes it reboot too.

I tried to follow a guide found on fairphone reddit, looking in parallel at original post on these forums to be sure I don’t make any mistake (I picked the LineageOS 16 because it was ticked green, I wanted to play safe).

I’m trying to get back to stock rom, by following the recommended script that I plan to execute manually one line at a time.
After downloading and extracted the stock rom via links provided here, I can’t find product.img, nor system.img nor vendor.img niether on A.0110 nor in A.0105.
What did I miss ?

I’m on Windows 10 but am using MobaXterm powershell (with correct path variables set to adb and fastboot executables).

I’ve exhausted all my options. Any help is appreciated.

Thank you !

You just have to press the power button to dismiss this message and for the phone to continue booting.
Whether the phone would boot successfully then is a different question.

Then it reboots and goes back to “your device software can’t be checked for corruption, please lock the bootloader” (normal behaviour since I unlocked the bootloader), then continues to boot and end up in the exact same screen starting with “your device is corrupt”. I’m stuck in a loop.

I suggest you to follow again fp3_flash_stock with the images given in the README.

I have also updated the README to add some tips. (flash twice, erase userdata and the 30 secs warning)

You should install Windows Shell for Linux on your computer or use a live USB to run the script. (If you have Git, use git bash)