<![CDATA[Can't get into fastboot after installing UT on Fairphone4]]>So I installed and tested UT on my FP4, and it just isn't quite for me yet. I was going to re-install the FP4 ROM as per Fairphone's instructions, however I can't get into fastboot mode from the bootloader.

I use "volume up + power" key to get into UBports Recovery menu, then select Advanced > 'Enter fastboot'. But from there, the device just becomes unresponsive, and it isn't recognized by the Fairfphone flashing utility (using Windows). If I hold power button I get an active black screen, and device remains unrecognized by flashing utility.

(Selecting "enable ADB" from the same menu gets me to a black screen with "ADB enabled", but again the flashing utility doesn't recognize the device.)

Using the SDK Platform Tools in Windows, the device is recognized when UT is booted up but when I attempt to run "adb reboot bootloader" I get the error "Failed to write reboot parameter file" Permission denied". Developer Mode is enabled in UT.

I'm at a loss here...any ideas on why I'm failing to get into fastboot?

]]>https://forums.ubports.com/topic/11294/can-t-get-into-fastboot-after-installing-ut-on-fairphone4RSS for NodeTue, 10 Mar 2026 16:14:56 GMTSun, 31 Aug 2025 09:12:52 GMT60<![CDATA[Reply to Can't get into fastboot after installing UT on Fairphone4 on Wed, 24 Sep 2025 16:36:04 GMT]]>@cristodcgomez sorry I was unclear: I have also tried selecting "restart" from the bootloader screen as per your hint above, and that also didn't result in the phone being recognized by ADB.

My extra attempt was to go through the recovery menu, which just locks the device when I select the fastboot option.

At this point I feel like something went wrong in the UT install that has messed up my phone's ability to access fastboot.

]]>https://forums.ubports.com/post/88336https://forums.ubports.com/post/88336Wed, 24 Sep 2025 16:36:04 GMT<![CDATA[Reply to Can't get into fastboot after installing UT on Fairphone4 on Wed, 24 Sep 2025 13:34:14 GMT]]>@owd200 But you're restarting to recovery... in the first screen you see "recovery mode", use vol keys to switch it to the fastboot option. In theory, it should land again in the same screen after restart and fastboot should recognize the device in your PC

]]>https://forums.ubports.com/post/88328https://forums.ubports.com/post/88328Wed, 24 Sep 2025 13:34:14 GMT<![CDATA[Reply to Can't get into fastboot after installing UT on Fairphone4 on Tue, 23 Sep 2025 04:24:35 GMT]]>@cristodcgomez you gave me hope, and I tried...but this isn't working either 😢

I can get it into this screen (no ADB/fastboot recognition):
12a0d4a9-7434-4710-9997-966c84012f3f-image.png

Then I can reboot into "recovery mode"
75b5dd5f-0bba-4b2f-ad5a-8a7c572838c6-image.png

As soon as I attempt "Enter Fastboot" option here, the phone locks and I have to long-press the power button to restart:
d0811d0a-c67a-4059-94f1-69d84717ead0-image.png

In none of these screens is the phone recognized via ADB. When UT is loaded up, the device is recognized, but I can't send it commands such as to reboot.

]]>https://forums.ubports.com/post/88285https://forums.ubports.com/post/88285Tue, 23 Sep 2025 04:24:35 GMT<![CDATA[Reply to Can't get into fastboot after installing UT on Fairphone4 on Mon, 22 Sep 2025 08:06:17 GMT]]>I faced this in the past. The steps I made for get back fastboot was:

  • Turned off the device (battery out 10 secs)
  • With the phone off, volume down + plug in USB
  • IN THAT MOMENT you'll see fastboot but it won't be detected, you need to select in the fastboot options to restart (again) into fastboot mode.
  • Once it restarts, you should be able to detect the device with "fastboot" command and be able to reinstall ubuntu (what I did using the UT installer tool) or reflash android
]]>https://forums.ubports.com/post/88264https://forums.ubports.com/post/88264Mon, 22 Sep 2025 08:06:17 GMT<![CDATA[Reply to Can't get into fastboot after installing UT on Fairphone4 on Sun, 21 Sep 2025 01:21:19 GMT]]>This is what I'm seeing when attempting to flash the original FP4 OS using Fairphone's utility while in the bootloader, with "FastBoot Mode" in red letters and "DEVICE STATE - unlocked":
8d5b6c3f-f7f4-4c9c-b76e-be969b1f3e4f-image.png

Again, the device is in Developer Mode within UT, and it shows up to ADB when UT has loaded, but ADB command to reboot is refused.

]]>https://forums.ubports.com/post/88240https://forums.ubports.com/post/88240Sun, 21 Sep 2025 01:21:19 GMT<![CDATA[Reply to Can't get into fastboot after installing UT on Fairphone4 on Sun, 21 Sep 2025 01:16:04 GMT]]>@Tafitson Thank you, this did get me into fastboot mode. I also found that Fairphone's method of holding "volume down" + plugging in USB works, too.

Now when I'm in fastboot mode, I can't get the computer to identify the device (tried on both Linux and Win10). It shows up just fine when UT is running and I use:

./adb devices

command in Win10.

But then if I try to use the command:

./adb reboot bootloader

Then I get the error "Failed to write reboot parameter file: Permission denied".

That combined with the lack of device detection in fastboot makes it seem like the "Enable Developer Mode" option isn't correctly enabling ADB on the device or something? I don't know, I'm at a loss.

]]>https://forums.ubports.com/post/88239https://forums.ubports.com/post/88239Sun, 21 Sep 2025 01:16:04 GMT<![CDATA[Reply to Can't get into fastboot after installing UT on Fairphone4 on Tue, 16 Sep 2025 16:14:23 GMT]]>@owd200
Having the same Issue, so I searched through this Forum and found this: https://forums.ubports.com/post/69548
"To enter fastboot I had to

sudo reboot -f bootloader

in the UT terminal"
This worked fine for me, hope it helps.

]]>https://forums.ubports.com/post/88185https://forums.ubports.com/post/88185Tue, 16 Sep 2025 16:14:23 GMT