DSU Accident to Fast boot Loop can't boot Android

I had wanted to try and see if DSUs, Actualización dinámica del sistema (DSU)  |  Plataforma  |  Android Developers, would help in testing.

It seems to have become stuck? I’m not sure if my data is recoverable / how I would reset if I needed to.

This article suggests a similar error when the bootloader is locked.

I’m not sure if the next thing to do is to try and unlock the bootloader? How do I send commands? I’m used to adb/wireless adb when the phone is bootable?

Any suggestions on what I should try next?

I’m not sure why the photograph makes it look the screen is damaged as it isn’t

Did you enable OEM unlocking beforehand, what is the output of fastboot flashing get_unlock_ability? :thinking:

Otherwise you won’t be able to unlock your bootloader.

1 Like

Thanks for the reply! I’m not sure I quite understand that. My Fairphone 5 is new so I don’t think it’s unlocked. Do I just plug the usb cable into a laptop with power shell up? Do I leave the phone on the fast boot mode screen as shown in the photograph?

In that case I’m assuming you didn’t enable it. Unlocking the bootloader would wipe your data anyway, so that’s probably not what you want.

What steps did you follow exactly, and what were you trying to achieve?

Since GSIs shouldn’t stay around for a reboot unless you make them sticky, did your phone manage a full reboot at some point before you ended up here?


I clicked the DSU image in developer options and then clicked restart to use the image. And it booted to the screenshot

Definitely didn’t unlock bootloader

And what happens if you select START on that screen, does your phone display the boot animation (I presume it’s still dancing blue dots?) for a while or does it immediatelly fail and throw you back to a Fairphone logo and the bootloader afterwards? :thinking:

Any error messages during the early boot process (before you end up in the bootloader screen)?

Edit: The more I read about people with similar problems the more this looks like a case where only contactsupport can help you. All solutions so far would involve an unlocked bootloader, if your phone doesn’t boot on it’s own.
If you can boot into recovery you could try a factory reset but that doesn’t restore partitions, not sure if that clears a DSU/GSI (and you would loose your data).

There really should be a big warning in the docs about not attempting it without an unlocked bootloader, and the system shouldn’t let you enable it if it’s locked.


I haven’t been able to fix this

Are you still able to boot into recovery? :thinking:

I haven’t been following the FP5 releases (I’m on FP4), but if there’s a newer OTA available than what’s on your device you should be able to install a ota.zip via adb sideloading in recovery.
That should work with a locked bootloader and maybe that clears the DSU, no idea if it does honestly but worth a try :crossed_fingers:

Did you contactsupport in the meantime, what’s their response?

1 Like