Broken nvidia display driver for Thinkpad T460p / GeForce 940MX

Question

When I start my Ubuntu 20.04 normally, I get an (backlit) black screen.

When I hold Shift during startup, I can see the grub startup menu:

I can choose "advanced options" and then the recovery mode and it starts with a low-resolution and without internet.

I have purged all nvidia drivers in the hope that this would fix the issue. It didn't. What can I do?

What I've tried

nomodeset

When I replace "quiet splash" by "nomodeset" in the boot options, I get the following instead of a black screen:

I can also switch with Ctrl+Alt+F1-F7 and I see that something changes, but I cannot read anything.

Internet in Recovery mode

With this guide I could get internet in recovery mode. I could install another nvidia driver, but it didn't help :-(

Defect graphics card?

Could it be that the nvidia graphics card broke and the Intel "on-board" graphics chip still works?

Within the recovery mode, I get:

$ nvidia-settings

ERROR: NVIDIA driver is not loaded


ERROR: Unable to load info from any available system


(nvidia-settings:4594): GLib-GObject-CRITICAL **: 11:34:54.538: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
** Message: 11:34:54.541: PRIME: No offloading required. Abort
** Message: 11:34:54.541: PRIME: is it supported? no

And:

$ sudo lshw -c video
[sudo] password for moose: 
  *-display UNCLAIMED       
       description: 3D controller
       product: GM108M [GeForce 940MX]
       vendor: NVIDIA Corporation
       physical id: 0
       bus info: pci@0000:02:00.0
       version: a2
       width: 64 bits
       clock: 33MHz
       capabilities: pm msi pciexpress bus_master cap_list
       configuration: latency=0
       resources: memory:f1000000-f1ffffff memory:c0000000-cfffffff memory:d0000000-d1ffffff ioport:d000(size=128)
  *-display UNCLAIMED
       description: VGA compatible controller
       product: HD Graphics 530
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 06
       width: 64 bits
       clock: 33MHz
       capabilities: pciexpress msi pm vga_controller bus_master cap_list
       configuration: latency=0
       resources: memory:f0000000-f0ffffff memory:e0000000-efffffff ioport:e000(size=64) memory:c0000-dffff