Comment 8 for bug 1764005

Dell XPS 15 9550 running Ubuntu MATE 18.04 daily is also affected.

Graphics: Card-1: Intel HD Graphics 530
           Card-2: NVIDIA GM107M [GeForce GTX 960M]
           Display Server: x11 (X.Org 1.19.6 )
           drivers: modesetting (unloaded: fbdev,vesa)
           Resolution: 3840x2160@60.00hz
           OpenGL: renderer: Mesa DRI Intel HD Graphics 530 (Skylake GT2)
           version: 4.5 Mesa 18.0.0-rc5

Please find a tarball attached that includes Xorg.log, gpu-manager.log and dmesg.

The nvidia 390 drivers were installed via the Additional Drivers UI. On next boot after plymouth splash is shown the screen is black. Switched to tty1 and tried to run `sudo prime-select nvidia` which reported the nvidia profile was already set. So I ran `sudo prime-select intel` and on next boot was presented with the display manager.