I need to fix a black screen problem (after the nvidia driver update), so I tried to enter recovery mode (many times). The system gives me only about one minute to work in recovery mode, then it starts to boot, then it hangs with top-level recovery menu shown on the screen. So, my only option after that is the cold boot.
Is it a kind of timeout in recovery mode? If yes, how to control it?
(Xubuntu 16.04 with kernel 4.4)