Device is corrupt - stuck in fasboot screen

[lal]

Dear all

I am new to Android. I got a Fairphone 5. I installed eOS successfully. When I tried to lock the bootloader, i got a message saying my device is corrupt and will not reboot or something like that.

I just checked Install /e/OS on a Fairphone FP5 - “FP5” and learned that may be my e OS and Fairphone 5 security patch could be different. I recently installed and updated my Fairphone 5 to Android 15 using Android platform tools. I used FP5-VT28-factory.zip file to run the bash. I successfully installed the Android OS. Then I used the e OS installer and successfully installed e OS too.
Everything was working perfectly until I did fastboot flashing lock command.
Now that I have locked my fastboot screen, I am unable to do anything. My phone keeps showing me the same screen. What can I do ?

Please suggest. I am starting to think that I have bricked my phone and I will not be able to use it any more.

Regain your privacy! Adopt /e/OS the deGoogled mobile OS and online services

[tcecyk]

for fastboot oem allow-flashing, do you get the same return as at My new fairphone blocked in bootloop - #8 by clemb8 ?

[mihi]

Did you check securits patch before installing? Did you try to unlock the bootloader again?

[lal]

@tcecyk & @mihi Thank you so much for the quick response. After doing some additional reading and reviewing the links you shared, the below are some further information.

I used the below information to lock the bootloader.

source: https://support.fairphone.com/hc/en-us/articles/10492476238865-How-to-unlock-and-re-lock-the-bootloader

in the above screenshot in step 6 it says, “Repeat steps 3 and 4”. It did not say how to perform Step 3. After Step 4, I put Fairphone in fastboot mode NOT by clicking the Volume + then power button. Instead, I let eOS successfully load, then enabled developer mode, enabled OEM unlocking in settings again (it was unchecked) and then used android platform tools to issue the command fastboot flashing unlock (was a very careless mistake, I hate myself). Then entered fastboot mode and then entered fastboot flashing lock command. After an automatic restart I got stuck in fastboot screen. I messed up.

Now I have the below questions:

1. After step 4 above i.e. running the ./fastboot flashing lock_critical command what does step 5 “Follow the instructions on the Fairphone screen” mean ? It does not mean enable developer mode, turn on OEM unlocking, etc. Am I right ? It just means select language, skip wifi setup, skip fingerprint setup, etc. and restart into fastboot and then run fastboot flashing lock while phone is connected to the computer. Am I right ? I need not enable anything in the Fairphone after ./fastboot flashing lock_critical.

2. @mihi In response to your question, “Did you check security patch before installing?” - in this link /e/OS Installer it said, “Before proceeding with the installation, verify if the latest Android firmware is available for your device”. Hence, I downloaded FP5-VT28-factory.zip as shown from the below link and successfully installed it. Was that a mistake ? After installing I tried to update and verified that there was no update. The security patch was latest as of July 2025 or something like that. It must be June 2025 security patch level. I remember seeing something like that. I know that it would not update anything more and its the latest as of 2 Aug 2025.
   

   
   
   Source: https://support.fairphone.com/hc/en-us/articles/18896094650513-How-to-manually-install-Android-on-your-Fairphone#01HB8ZZ1BMMQNSNMFT3YXDBXA0

3. @mihi in response to your questions, “Did you try to unlock the bootloader again?” - Since I have been messing things up despite good documentation, I am a bit cautious to try unlock the bootloader again. I am thinking of taking some time and understand everything and then do things systematically.

Some unrelated background: I am liking Android so much, I have been using iPhone for over 16 years now (got it free as a company phone). Previously I was on Symbian OS Nokia phone since 2003. I have developed applications for Symbian back in college. I am slowly liking Android and eOS, it looks like apple iOS to be for some reason. Day before yesterday I installed Ubuntu touch on this same Fairphone5 and had to uninstall as my phone was overheating while doing basic stuff like checking email and watching Youtube on mobile browser. I saw all the nice ubuntu touch youtube videos and thought it could be daily driven - I was wrong and disappointed. I wanted to make a switch from iPhone to something better. I think I will wait some 10 years for Pinephone to get better. Meanwhile, I thought I will use Fairphone 5 Android, but did not like the google search bar and AI prompts and other pop ups. After disabling AI and other google intrusions, I used Fairphone 5 Android for 4 months and now I had enough. Out of frustration, I decided to install Ubuntu touch and it did not work out. I am hoping to finally settle with e OS. I did not use eOS yet, but I think i will like it. For the past 4 days, I have been running commands on terminal with very little research and less regard to outcomes. Hence slowing down a little bit.

4. @tcecyk
   (a) You wanted me to try the below steps first. Am I right ?
   

   
   
   source: Fairphone 5 UNBRICK w/ Bootloader locked - Android 14(+?) Bootloader Only - #18 by mikkop - Guides - Fairphone Community Forum
   (b) You do not want me to try the below only if the above (a) did not work. Am I right ?
   
   
   
   source: https://xdaforums.com/t/fairphone-5-unbrick-android-14-bootloader-only.4711932/

5. @tcecyk or @mihi - Did I do the wrong thing by installing FP5-VT28-factory.zip with June 2025 security patch first and then installing eOS on top of it ? I could not tell if I had installed the eOS Android 14 official or eOS 15 community version. I simply clicked on the eOS web installer and proceeded. Since I had Android 15 already on my Fairphone 5 did I automatically install Android 15 community ? I know I cannot bootlock community edition. Is that what could have happened in my case?
   

   

I am so sorry for this long message. I am just trying to share more details so that people may help.

[aibd]

May I just offer a very short answer. Based only on what I consider bad advice for this phone to fully update before /e/OS automated instsall. I think there is a chance that you were / are in this situation. Fairphone 5 – Installing latest eOS 3.0.4 official build: bootloader locking fails with "corrupt" error - #4 by aibd

Edit working though easy_to_answer. No eosinstaller would not have installed community. Change of Android version is bsically OK with this install method.

[lal]

@aibd Thank you for taking the time to help. I highly appreciate this.

So from the above link you shared I understand that I tried installing a A14 official or A15 community (could not tell which one) using the /e/OS web installer automatically. Both the A14 official and A15 community version of /e/OS has a security patch dated 2025-06-01 that is older than the security patch dated 05 June 2025 on my Fairphone 5 device (shown in the image below). Hence my device got bricked.

@aibd In this case can I try installing Fairphone 5 Android version 13 then try to install /e/OS 14 or 15 and finally unlock bootloader successfully ?

or do you recommend installing Fairphone 5 Android version 15 and then do not lock the bootloader. Keep using unlocked phone and wait until /e/OS releases new security patch which is newer than the current Fairphone 5 Android version 15. Once latest /e/OS security patch is released then update the /e/OS and only then try lock the bootloader.

Please suggest @aibd

@tcecyk , @mihi - I tried /platform-tools# ./adb devices

I could not get my device listed using this command.

When i tried /platform-tools# fastboot oem allow-flashing

I got the below

FAILED (remote: ‘unknown command’)
fastboot: error: Command failed

When i tried /platform-tools# adb reboot bootloader

I got the below

error: no devices/emulators found

I dont know if its good news that I am able to unlock and lock my bootloader

As you can see the below command to unlock and lock my bootloader works.

/platform-tools# fastboot flashing unlock
OKAY [ 0.035s]
Finished. Total time: 0.035s

/platform-tools# fastboot flashing unlock_critical
OKAY [ 0.035s]
Finished. Total time: 0.035s

I am unable to do anything other than lock and unlock my bootloader. Since Android platform tools “./adb devices” command is not showing my device I do not know how I can proceed to reinstalling Android 13 or anything.

Any help on next steps is highly appreciated please.

[aibd]

In order to move forward you will need a working Fastboot mode.

Please show the response from

fastboot devices

… assuming that you can get Fastboot mode.

And does your Bootloader screen show unlocked in red?

If the above is positive you are out of trouble.

@lal

command to unlock and lock my bootloader works.

For general peace of mind please do not run any Lock commands. Unlocked is just fine.

@lal

Please suggest

I will once I know the device state … for starters I would tend to avoid a15 … only as it is a bit new and I am conservative.

• Late edit. a15 is not yet available in official … hence the suggestion to avoid … it just introduces a “complication”.

[lal]

@aibd

When I ran /platform-tools# fastboot devices

I got the below

<8DigitDeviceSerial> fastboot

My bootloader screen show unlocked in red. What do I do next please ?

[aibd]

It has been a very long day for me … perhaps for you too.

You are in the clear.

I think you will be fine to reinstall the FairphoneOS you had previously.

Perhaps sleep on it for a while.

[tcecyk]

hard to answer, too much questions. You weren’t fully locked yet, so you could still unlock. Going into “flashing lock_critical” would’ve been the end of your adventure.

In unlocked mode, rollback protection is ignored. You can use /e/OS and keep it unlocked for a few weeks until security patch level… levels out.

That oem command is custom, but seems to work for some to flash stock images that get the green light (as the device trusts the signing keys) even when already in a locked state.

[lal]

@tcecyk I have successfully installed Fairphone Android 13 with security patch June 5 2024. I am planning to manually install IMG-e-3.0.4-a14-20250708507308-official-FP5.zip from /e/OS official FP5 download. This /e/OS has a security patch of 2025-06-01.

Clearly I will be able to lock the bootloader again. What do you think ?

Or do you recommended I wait for weeks until the patch is same or greater ?

[tcecyk]

you updated to FP5.VT28 with a 2025-06-05 patchlevel before (while locked I think?), that rollback index is stored and honored when relocking again, doesn’t matter what you install (with a lower patchlevel) while unlocked.

If it’s the same year and month, Imo the 1st to 5th distinction matters, but can’t verify, so I’d wait for the next months patch level before relocking. If v3.1 /e/OS brings a 2025-07-01 patchlevel than you can go ahead.

[lal]

I have successfully installed /e/OS. I will wait until the next security patch from /e/OS before I lock the boot again. I installed /e/OS from Android 13 as per @aibd advice and not Android 15 like last time.

I was not able to move away from the bootloader initially. I thought of reinstalling Ubuntu touch and failed because the setup was not able to enter fastbootd. The message said - setup unable to enter fastbootd, try restarting the setup from fastboot mode again. I did not know what to do, there was Postmaker OS option to try. I installed it and was successful. Before reinstalling Android I installed Postmaker OS with GNOME. Camera was awful, no sound - it kept showing dummy output in drivers. Terminal did not recognize few commands. Yet, I was surprised that I was able to move out of the bootloader. Postmaker setup did some firmware update. I am thinking may be this unbricked my phone. Nevertheless, I like /e/OS now. so far so good.

Once I get the next security patch from /e/OS, I will come back here for suggestions.

Thank you everyone for your patience and determination in helping me out.

[aibd]

@lal

as per @aibd advice.

Never mind if this might have been a miss quote; I did not find it clear which FairphoneOS you has previously. When I replied to you last night you had a forum username starting with the letter “P”.

How did you manage to change your forum ID?

[lal]

I said “please suggest” and you said

@aibd

for starters I would tend to avoid a15

lol

I sent you a private message on how I changed my forum id. I changed because I did not wanted to share my full name.