Unable to Install Fairphone OS via Fastboot (Android 10/11/13) on Fairphone 3

Dear Fairphone Support,

I hope you’re doing well.

I’m reaching out regarding an issue I encountered while attempting to manually install Fairphone OS on my Fairphone 3 using the fastboot method.

I have successfully unlocked the bootloader by following the steps provided in the Manage the Bootloader guide. However, when trying to flash the OS via the fastboot method for Android 10, 11, or 13, the process stalls at:
looking for connected device(s)…
It does not progress beyond this point.

Surprisingly, when using the fastboot method for Android 9, the installation completes successfully without any issues.

Here are some additional details:

  • Device: Fairphone 3
  • Bootloader: Unlocked successfully
  • OS Versions attempted: Android 10 / 11 / 13 (unsuccessful), Android 9 (successful)
  • Method: Flashing via fastboot
  • Host System: Windows OS
  • Devices manager can find android bootloader device
  • ADB command ok during bootloader mode
  • Issue: Device is not detected during flashing for Android 10/11/13

I would greatly appreciate your guidance on how to proceed or if there are any known issues or additional steps needed for installing newer Android versions via fastboot on Windows.

Thank you for your support!

Thats impossible, in bootloader mode you can only use fastboot commands. So are you sure you are in the bootloader (screen on the FP showing device is unlocked) when you execute the script

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Welcome to the community forum.

As this really is a community forum, we are not Fairphone support, we are users like you.
Fairphone staff might read along occasionally, too, or not.
To reach Fairphone support please use the official means to do so … https://support.fairphone.com/

However, we can perhaps help, @yvmuell’s question is valid.

The clear distinction between ADB and fastboot is often unclear to users (probably because both commands are distributed together), as can be seen in the picture provided in this case. This is all about fastboot (aka bootloader), as you already correctly assume.

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Hi all,
Thank you for your response.
Indeed, I have trouble distinguishing between ADB commands and bootloader commands — my apologies for the confusion.
What I meant to say is: I followed the steps on the official Fairphone website to unlock the bootloader and successfully completed the unlock process.
However, when trying to install the OS using the image files provided under Download the relevant package, only the following package worked and was able to detect the device and complete the OS installation:
Android 9 File name: FP3_legacy_FP3-REL-2.A.0134-20200703.120010-user-fastbootimage-v2.zip
Other versions (Android 13/11/10) all get stuck at the “looking for device” stage.
I’m wondering if anyone else has encountered this issue and if there’s a known solution?
It’s possible that Legacy upgrade to Modern problem?

Also, here’s the bootloader unlock steps from the Fairphone website:
*Unlock your bootloader: *
Connect your Fairphone to your computer using a USB data cable.
Download the Android platform tools on your computer.
Extract the .zip you downloaded in the previous step and move the unarchived folder to your desktop.
Open a Command Prompt (Windows) or a terminal (macOS/Linux). You’ll use this to send commands to your Fairphone. For starters, navigate to the platform tools folder.
On Windows, type the command cd C:\Users[YOUR USERNAME HERE]\Desktop\platform-tools_r34.0.4-windows\platform-tools
and press Enter :leftwards_arrow_with_hook:.
On macOS/Linux, type the command cd ~\Desktop\platform-tools_r34.0.4-windows\platform-tools
and press Enter :leftwards_arrow_with_hook:.
Note that the exact name of the platform tools folder may be different from the example above.
Type adb devices and press Enter :leftwards_arrow_with_hook:. You will see a pop-up on your Fairphone asking if you allow USB debugging on this computer. Tap Allow.
Note
If a command doesn’t work, try prefacing it with ./. For example: adb devices → ./adb devices.
Next, type adb reboot bootloader and press Enter :leftwards_arrow_with_hook:. The phone will now reboot into fastboot mode.
While in fastboot mode, type fastboot flashing unlock and press Enter :leftwards_arrow_with_hook:. Follow the instructions that appear on your Fairphone’s screen. This action will wipe all the personal data on your phone.
After the phone reboots, boot into the fastboot mode once again.
Type in fastboot flashing unlock_critical and press Enter :leftwards_arrow_with_hook:. Once again, follow the instructions on your Fairphone to finish unlocking. This action will wipe all the personal data on your phone.

If the phone was correctly in fastboot mode everytime you tried this, I could see three possible causes for issues.

  1. Different versions of the fastboot command being used, leading to different results.
    While the bootloader unlock instructions advise to download the current set of tools from the source and use those, the OS installation packages all have their own fastboot commands included, and naturally those are different versions over time. Perhaps there’s some incompatibility at play.

  2. The install processes differ.
    From Android 10 on, the install on Windows opens Git bash to then execute a Linux/Unix style shell script. This way Fairphone only have to provide one install script (flash_fp3.command) covering Linux, Mac and Windows all the same.
    This was different before in the Android 9 install package with distinct programs covering the different platforms.

  3. Windows version issue.
    Your bash screenshot shows a rather retro window design, and this is not a bash feature (I had a look), so either your window design is because of old Windows, or because of a retro theme for current Windows.
    Which Windows version are you using?

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Thanks, everyone!

I eventually found the solution in flash_fp3.command.
Starting from Android 10, there’s a device verification step.
Bypassing the check fixed it (my device is a bit unusual).
Appreciate the help!

flash_fp3.command check devices info as below.

Toggles

AUTO_REBOOT=“true” # Control reboot behavior. Default is “true”
INTEGRITY_CHECK=“true” # Checksum run. default value is “true”
RELOCK_BOOTLOADER=“true” # Relock the bootloader after flashing, default value is “true”

Target device info

PRODUCT=“Fairphone 3”
PRODUCT_ID=“FP3”

Paths/files

ROOT_DIR=“$( cd – “$( dirname – “${BASH_SOURCE[0]}” )” &> /dev/null && pwd )”
IMAGES_DIR=“${ROOT_DIR}/images”
SHA256SUMS=“SHA256SUMS” # Path to file not needed, only the filename

Abort the script (and wait for a key to be pressed).

abort_now() {
echo -en “$RED”
read -rp “ERROR: Aborting now (press Enter to terminate).” a
echo -en “$NC”
echo “”
exit 1
}

Check for connected phone

find_device() {
echo “INFO: Looking for connected device(s)…”
DEVICE_FOUND=“false”
while [ ${DEVICE_FOUND} = “false” ]; do
serial_numbers=

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