[Solved] Problem to unlock device via fastboot on FP4

Help Fairphone 4
3

If adb displays the device but fastboot doesn’t, in my experience it means you should try another cable (as xblax suggested).

4

this is exactly mentioned very often in several boards…

Often, the problem is:

  1. the USB Cable (somteimes because of C-C instaed of A-C)
  2. the USB port ot the PC/laptop

it works well for adb devices but not for fastboot devices and data transfer

try to change the cable or USB port.

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5

I am just guessing here but could it be that the command demands “sudo” ?

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6

the commands for itself not.

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7

However reading this…

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8

I agree, this needs sudo if the correct udev rules aren’t installed.
Either use sudo or:

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9

in linux, the android-sdk-common packet should set the udev rules, so that sudo is not needed.
in theory…

10

I think I am in fastboot mode but I don’t know.
I unlock EOM. USB debug enabled.
I restart my FP4, unlock screen (“Fairphone 4 5G” appear in Dolphin)
When I do : $adb reboot bootloader, the phone reboot (connection seem ok) and display a screen where “FastBoot Mode” is in red and another red line below “DEVICE STATE - locked”
“adb devices” command list no devices attached.

11

Your phone is in Fastboot Mode, yes.

What is the output of sudo fastboot devices? (adb is only for managing the phone in other states)

12

the command gets nothing

13

Ok, so sudo permissions are probably not your only problem.

Try using a different USB cable / port as @xblax suggested and see if you can get the device to show up.

14

sudo fastboot devices gets nothing

15

once again. change cable and/or USB port.

17

adb reboot bootloader restart FP4, I think the Cable/port is ok. No ?

18

:point_up_2::point_up_2::point_up_2:
That’s very much the case, just because it works with adb doesn’t necessarily mean fastboot will “like” your cable.

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19

android-udev-rules is installed.

$adb devices                                                                                                
List of devices attached
* daemon not running; starting now at tcp:5037
* daemon started successfully
[number]        device

but fastboot device still gets nothing

20

I only have 2 usb C cables and I doubt that it comes from the cables that work well with other devices when I exchange data…

21

once again. change cable and/or USB port.

22

what version?
C2C or A2C?

23

fastboot is evil in this regard , unfortunately your best bet is to try all possible USB cable, USB port, computer combinations you have available.

My laptop does not recognize my FP4 using fastboot - adb works - but using the same cable with the same port with a different phone works just fine. Using the very same cable my server recognizes both phones using any USB port :confused:

Heck, my server doesn’t care if I use a 10m extension cable in between xD

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