It seems this is the only way to go back. Currently, my bootloader is still unlocked (I get a nasty message at startup with a yellow triangle saying “the boot loader is unlocked and software integrity…”).
Will this guide help me get rid of this message for good?
I’m currently running :
EOS 3.0
Android 13
Android security update April 5, 2025.
I was on Android 14 before switching to e/OS
Which version should I choose to be sure not to brick my device (not sure of the term, but I read that it’s an important thing to consider ^^)?
Thank you for your reply. I’ll make a note of that. This version does indeed have the same security update level as my current E/OS.
And regarding my question about the bootloader unlocked message at startup, will the guide allow me to lock it again and make this message disappear? Safe? I just want my Fairphone back to the way it was out of the box
As you will have read on the “Manually install Android” page, for a FP5 the only method currently available is “Flashing with Fastboot”, by which “your data is always wiped”. That happens when you unlock the bootloader, and, later, when you lock it again. This means that all the apps you’ve installed on /e/OS, and all your data (files, contacts, photos, music, app configurations, etc.) will be erased. The phone will be returned to the state it was in when it came “out of the box”, except that you’ll have the latest version of Fairphone Android.
This means that you must ensure that you have usable copies or backups of all data that are important to you. You’ll have to put the data back on the phone using the appropriate methods, once you’ve finished. This can be simplified if you have used cloud synchronisation wherever possible, such as for contacts, calendar, maybe files too. You might want to find out more about backups before going any further.
Regarding the bootloader, as stated above, when you unlocked the bootloader, all your data were wiped. That didn’t matter when the phone was new. But remember that they are also wiped when you lock the bootloader again. If your bootloader is currently unlocked, even if you decide to stay with /e/OS, do not lock it, in any case for the moment, without backing up your data, as they will be erased.
If you intend to lock your bootloader after reverting to FP Android, do it as soon as you’re sure that the phone is working properly.
Thank you for these explanations. I spent the evening trying to install Android. Unfortunately, I was unable to get the phone, put in fastboot mode, to be recognized by the PC when I typed “adb devices” in the terminal. I had activated USB debugging. I installed USB drivers etc… impossible to display it in the terminal in fastboot mode… I’m tired
Adb devices doesnt help you with fastboot and USB driver neither…
So read this when you use windows
You put your phone into fastboot/bootloader mode by turning it off and than restarting by homding power+vol-down
This advise would not prevent a brick and can rather cause exactly this (although more important for the FP4) best is to lock before booting into the system, however not possible with the FP script. Thus the most important thing is, only flash a version with a newer security patch level, to be as safe as possible see @Urs post
I admit I’m not very good at expressing myself because I’m not familiar with the vocabulary
I did exactly what was indicated in your link. I even manually updated the drivers in Device Manager with the Google drivers found here: Télécharger le pilote USB Google | Android Studio | Android Developers
I got stuck at the step where, after putting the phone in Fastboot mode, plugging in the device (a little sound from the PC indicates that the phone is recognized), and testing the connection via the terminal by typing “adb devices,” it couldn’t find my phone.
However, it found it by typing the same thing when the phone was in the classic interface. It only doesn’t recognize it in Fastboot mode…
I should point out that my bootloader is already unlocked since I did it for the easy e/OS installation and I didn’t relock it afterward (I still get the message with the yellow triangle at startup). So I have relatively few steps to follow. I just need to get my phone recognized in Fastboot mode.
Sorry for this Google translation. I’m French and my English isn’t good enough to communicate easily
Because you need to type in fastboot devices in fastboot…
Normal mode is for adb and fastboot/bootloader mode (your screenshot) is for fastboot
And to be clear when this does not work you must search for bootloader driver manually when the FP is connectwd in this mode to your computer, I dont think standard USB driver include those.
Your phone is in fastboot mode at this point.
You need to use the fastboot command then, not the adb command.
Fastboot mode (also known as bootloader) and ADB (Android Debug Bridge) are two different things, so the fastboot command and the adb command do different things in different states of the phone.
Notice how the next commands in the tutorial you linked to start with fastboot, not with adb.
Likewise, on Windows for ADB and fastboot you will need different drivers. The USB driver you linked to will most probably not help you with fastboot mode, it’s most probably an ADB only driver, because the Android Studio context in which it is given doesn’t need anything else.
With the phone connected to the computer in fastboot mode, here’s an animation from a Fairphone support page showing the install process via Windows Update - Optional updates …
When I typed Fastboot device in the terminal, in fastboot mode, I got my phone’s S/N. So, in fact, everything was fine. I just got stuck because the guide said to type “adb devices” and it didn’t find anything.
I’ll try again tonight with your explanations, thanks again!
Quick additional question: after finally switching back from e/os to Fairphone Os, I connected my phone FP5 to the computer. And the device name that appears is strange:
There is such an option?
Anyway, it could as well be the driver used by Windows deciding on an odd name.
The important thing is that the connection works. MTP is not very device-specific, it’s a general and universal method of file transfer.
If you don’t like the optics of it, you can perhaps experiment …
If you don’t intend to use ADB and fastboot again, feel free to not do the last steps from the Android SDK Platform Tools onwards.
more recent security patch level than the one you are currently on, see 
