I can't make adb devices recognize my Fairphone 4

musen2100

Hi everyone

I have installed Ubuntu Touch on Fairphone 4, everything worked perfectly. Unforunately after trying it for some time, I have decided it is not for me. I am attempting to install LineageOS instead, which requires me to boot into fastboot mode. This requires me to have USB debugging enabled, but even though I did enable Developer Mode on the phone, the phone is not recognized when i use

adb devices

The output is

List of devices attached

I have tried plugging it in USB-2, USB-3, USB-C ports, even different computers. Nothing works and adb can not recognize the phone. Does anyone have an idea on how to solve this issue? I even tried Erase & Reset All, and reenable developer mode with no luck.
Any help is appreciated, thank you.

musen2100

@mrt10001 Thanks for your quick response. I forgot to mention it, but I couldn't even boot into fastboot the manual way. I actually figured out the issue. It seems it was the USB cable after all, because two of my cables refused to work, even though they normally work fine. I used a third, through USB-2 as well and were luckily able to fastboot the manual way only. It was also very quick and easy to install lineageOS, so I already have that now. Thank you for your help

MrT10001

@musen2100 Yes, you have found an issue with developer options that ADB doesn't always show up. Power the device off and boot into fastboot the manual way.

To get ADB working, I have always had to install UT Tweak Tool and use the option on that within system. However, it doesn't work with Focal (20.04) if you are using that.

musen2100

@mrt10001 Thanks for your quick response. I forgot to mention it, but I couldn't even boot into fastboot the manual way. I actually figured out the issue. It seems it was the USB cable after all, because two of my cables refused to work, even though they normally work fine. I used a third, through USB-2 as well and were luckily able to fastboot the manual way only. It was also very quick and easy to install lineageOS, so I already have that now. Thank you for your help

MrT10001

@musen2100 On a side note check out e/OS. Based on LineageOS, but with privacy in mind.