Black screen while nvidia driver is installed

I have installed Kubuntu 18.04 LTS and I want to use NVIDIA driver from nvidia.com.

My graphics devices are:

$ lspci | grep "VGA"
00:02.0 VGA compatible controller: Intel Corporation Device 591b (rev 04)
01:00.0 VGA compatible controller: NVIDIA Corporation Device 1c8d (rev a1)

I have installed their driver from multiuser session (without X), blacklisted nouveau through adding lines

blacklist nouveau
options nouveau modeset=0

into /etc/modprobe.d/blacklist.conf, the lines

rdblacklist=nouveau

into /etc/default/grub,
made

# grub-mkconfig -o /boot/grub/grub.cfg
# update-initramfs -u
# reboot

After reboot I obtain black screen, while from other tty a can run nvidia-smi which returns correct result:

$ nvidia-smi
Fri Apr 12 20:33:11 2019
+-----------------------------------------------------------------------------+
| NVIDIA-SMI 418.43       Driver Version: 418.43       CUDA Version: 10.1     |
|-------------------------------+----------------------+----------------------+
| GPU  Name        Persistence-M| Bus-Id        Disp.A | Volatile Uncorr. ECC |
| Fan  Temp  Perf  Pwr:Usage/Cap|         Memory-Usage | GPU-Util  Compute M. |
|===============================+======================+======================|
|   0  GeForce GTX 1050    Off  | 00000000:01:00.0 Off |                  N/A |
| N/A   39C    P8    N/A /  N/A |     49MiB /  4040MiB |      0%      Default |
+-------------------------------+----------------------+----------------------+
+-----------------------------------------------------------------------------+
| Processes:                                                       GPU Memory |
|  GPU       PID   Type   Process name                             Usage      |
|=============================================================================|
|    0       840      G   /usr/lib/xorg/Xorg                             8MiB |
|    0       880      G   /usr/bin/sddm-greeter                         38MiB |
+-----------------------------------------------------------------------------+

so driver looks installed properly.

My configuration file and logs are here: xorg.conf, Xorg.0.log, dmesg, journalctl.

The xorg.conf file was taken from Linux Mint installed at the same laptop where graphics starts properly with nvidia driver installed from repositories. Usage of xorg.conf produced during installation of the driver gives the same black screen (apart from absence of loading modesetting in Xorg.0.log).

Is it possible to run graphics with the latest nvidia driver at my system?

---

Additional information about my system:

$ mokutil --sb-state
SecureBoot disabled
Platform is in Setup Mode
$ ls /sys/firmware/efi
config_table efivars esrt fw_platform_size fw_vendor runtime runtime-map systab vars
# lshw -c video
  *-display
       description: VGA compatible controller
       product: GP107M [GeForce GTX 1050 Mobile]
       vendor: NVIDIA Corporation
       physical id: 0
       bus info: pci@0000:01:00.0
       version: a1
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress vga_controller bus_master cap_list rom
       configuration: driver=nvidia latency=0
       resources: irq:134 memory:de000000-deffffff memory:c0000000-cfffffff memory:d0000000-d1ffffff ioport:e000(size=128) memory:df000000-df07ffff
  *-display
       description: VGA compatible controller
       product: Intel Corporation
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 04
       width: 64 bits
       clock: 33MHz
       capabilities: pciexpress msi pm vga_controller bus_master cap_list rom
       configuration: driver=i915 latency=0
       resources: irq:130 memory:dd000000-ddffffff memory:b0000000-bfffffff ioport:f000(size=64) memory:c0000-dffff
$ lsmod | grep nvidia
nvidia_drm             45056  3
nvidia_modeset       1085440  6 nvidia_drm
nvidia              17592320  221 nvidia_modeset
ipmi_msghandler       102400  2 ipmi_devintf,nvidia
drm_kms_helper        172032  2 nvidia_drm,i915
drm                   458752  8 drm_kms_helper,nvidia_drm,i915

---

dkms status doesn't return anything:

$ dkms status
$

---

I have reinstalled the driver then installed bbswitch-dkms. But result of starting X is the same.

Here are Xorg.0.log and results of previously shown commands where result has changed:

$ lsmod | grep nvidia
nvidia_uvm            798720  0
nvidia_drm             40960  3
nvidia_modeset       1085440  6 nvidia_drm
nvidia              17592320  222 nvidia_uvm,nvidia_modeset
ipmi_msghandler       102400  2 ipmi_devintf,nvidia
drm_kms_helper        172032  2 nvidia_drm,i915
drm                   458752  8 drm_kms_helper,nvidia_drm,i915
$ dkms status
bbswitch, 0.8, 4.18.0-17-generic, x86_64: installed
nvidia, 418.43, 4.18.0-17-generic, x86_64: installed

The xorg.conf is the same as previously. The output of mokutil, ls /sys/firmware/efi, lshw, nvidia-smi is the same as earlier.

I have found one more relevant log: /var/log/gpu-manager.log. Here are these files for Kubuntu and Linux Mint (where driver from repository runs X successfully): gpu-manager.log.Kubuntu, gpu-manager.log.Mint. From the second log it is seen that bbswitch is used also. This was the reason to install it at Kubuntu, but for now I don't know how to use it...