Bluetooth adapter not detected on Linux

Solution 1:

Same symptoms as in the question happend to me on a Dell XPS 13 after installing Wacom software for a Intuos BT S tablet.

Solution for me was disabling Bluetooth in the BIOS, rebooting and enabling it in the BIOS again, as is said in this thread: https://ubuntuforums.org/showthread.php?t=2348005

Solution 2:

Are you dual-booting windows? If you are, make sure to disable FastBoot in Windows. This is from Intel Documentation:

About dual-boot with Windows and "fast-boot" enabled If you have a dual-boot machine with a recent version of Windows and start seeing problems during initialization of the WiFi device when booting Linux, the problem could be due to the “fast startup” feature on Windows.

With this feature enabled, Windows don't really shut down the entire system, but leaves things partially running so you can start the machine faster again. Try to disable this option, on Windows 10 it should be in “Control Panel→Hardware and Sound→Power Options→System Settings”, then disable the “Fast Startup” option in “Shutdown Settings”. This will cause Windows to fully shutdown and may solve the issue.

https://wireless.wiki.kernel.org/en/users/drivers/iwlwifi

Had a similar issue and figured out this was the reason.

Solution 3:

Whilst this is not an answer, I provide it here in the hope that it could be useful for people landing in this thread. Here you go:

I had troubles with my Philips SHB9850NC and I resolved the issue by installing pulseaudio-module-bluetooth. Later I've installed blueman too, which is a Gnome thing. Since I use KDE, I've removed blueman after that. Then troubles started to happen: my Bluetooth adapter vanished from existence.

The procedure below is intended to reinstall the entire Bluetooth stack for KDE, including pulseaudio-module-bluetooth. However, this didn't solve the issue. My Bluetooth adapter is still not detected.

$ sudo apt install --reinstall -y bluetooth bluez bluez-firmware bluez-hcidump bluez-cups bluez-tools pulseaudio-module-bluetooth
$ for cmd in unload load ;do sudo pactl ${cmd}-module module-bluetooth-discover ;done
$ for cmd in force-reload restart ;do sudo service bluetooth ${cmd} ;done