Same with my Dell E6520 with HD3000 and NVS4200M. When I switch to Nvidia I am stuck in a black screen just before the login screen.
The strange thing is that when I connect an external monitor through VGA port I can login and use the desktop on the external monitor but built-in display is still blank.
Each time I have to drop back to console and switch back to intel with prime-select command. to get the screen back.
Just after switching to Nvidia xorg.conf is deleted and if I copy a previously backed-up xorg.conf file Nvidia works but is broken again when I make a switch from Intel to Nvidia.
Same with my Dell E6520 with HD3000 and NVS4200M. When I switch to Nvidia I am stuck in a black screen just before the login screen.
The strange thing is that when I connect an external monitor through VGA port I can login and use the desktop on the external monitor but built-in display is still blank.
Each time I have to drop back to console and switch back to intel with prime-select command. to get the screen back.
Just after switching to Nvidia xorg.conf is deleted and if I copy a previously backed-up xorg.conf file Nvidia works but is broken again when I make a switch from Intel to Nvidia.