After d-u and updating form
nvidia-driver 470.74-1 to 495.44-0~siduction.3 there was no nvidia modul built observable. On reboot, obviously the modul failed to load ... no X.
Matters were complicated further by the fact that now nvidia-driver 470.74-1 is not installable anymore. Trying to resolve dependencies manually endet to no avail. Not evan purging nvidia comletely allowed a reinstall of v 470.74-1 afterwards.
Now the computer runs with nouveau driver:
# inxi -G
Graphics: Device-1: NVIDIA GK208B [GeForce GT 710] driver: nouveau v: kernel
Display: server: X.org 1.20.11 driver: loaded: modesetting unloaded: fbdev,vesa tty: 126x29
Message: Advanced graphics data unavailable in console for root.
For further investigation I would like to know what output I should generate with (broken) nvidia installed?