Laptop, lenovo 2020 R7000 savior, CPU - R7-4800 - h (nuclear), graphics - GTX1650;
An external display models: dell P2419H
After installed ubuntu18.04, the first thing to do is install NVIDIA driver, because after not external display, on the Internet to find the solution, finally solve with the following command:
delete X11 configuration file: sudo rm/etc/X11/xorg conf *
To regenerate the configuration files: sudo nvidia - xconfig
Switch to the n CARDS: sudo prime - select nvidia
Appeared after the title says, use sudo prime - select nvidia switch to cannot use notebook screen, showing only external display shows, with sudo prime - select Intel to switch to the nuclear can only display notebook screen, not external display,
The above two cases using xrandr commands can only see a display, use "Settings - equipment - show" also can't see the other monitors,
Access to the Internet to find a circle and no one encountered this problem, has long been known that CSDN master of BBS, so the younger brother come to consult! In this first thank you! [fuels]
Note: when using showing, black white text on a laptop screen showing the "files/dev/nvme0n1p6: clean, 174952/3751936, 2287986/15000064 blocks", the second line is "_"