Thank you for the detailed instructions! Here are my results:
- double checked in Android that OEM-unlocking and USB-debugging are toggled on in the developer settings. To make sure, I went again to “Settings>About Phone” and tapped on build number: message: you are already developer. Btw. Volume keys work under Android.
- booted into fastboot first by Volume-down+power and USB-cable plugged in, checked in terminal with
fastboot devicesthat device is reachable. - run
fastboot reboot bootloader– phone restarts, but ends up starting the system fully, no blue light. - reboot the system once more, making sure USB-debugging dialog pops up when starting. Then running
adb -d reboot bootloader– restarts the phone, but again, starting the system fully, no blue light.
Do you have an idea what could be done? My only next idea was to make a full factory reset and start over again: I’ve just completed this, but nothing changed.
The only idea I have found is that it could be a USB issue with macOS Sequoia. So I’ll try more cables. Thing is that I can connect to the device through fastboot devices, so this seems to contradict an usb problem.