Unable to connect other monitors, Lenovo L470

Question

No matter what kind of connection(VGA,HDMI via DisplayPort,DVI via DisplayPort) I tried, the monitor recieves no Signal from the Laptop. I have dual-boot with Ubuntu 20.04 and Windows 10, so i tried it on Windows and worked without problems. My guess is there is something going wrong with ubuntu. So i tried adding modes to xrandr, tried reinstalling the graphic driver, i tried older kernel versions and nothing worked.

Output of xrandr:

xrandr: Failed to get size of gamma for output default
Screen 0: minimum 1920 x 1080, current 1920 x 1080, maximum 1920 x 1080
default connected primary 1920x1080+0+0 0mm x 0mm
   1920x1080     77.00*

Output of lshw -C -display:

*-display UNCLAIMED       
       description: VGA compatible controller
       product: HD Graphics 620
       vendor: Intel Corporation
       physical id: 2
       bus info: pci@0000:00:02.0
       version: 02
       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

Output of dpkg --get-selections | grep mesa

libegl-mesa0:amd64              install
libgl1-mesa-dri:amd64               install
libgl1-mesa-dri:i386                deinstall
libgl1-mesa-glx:amd64               install
libglapi-mesa:amd64             install
libglu1-mesa:amd64              install
libglx-mesa0:amd64              install
mesa-utils                  install
mesa-va-drivers:amd64               install
mesa-vdpau-drivers:amd64            install
mesa-vulkan-drivers:amd64           install

I'm happy if you could help me.

Any ideas?

score 0 · Accepted Answer · answered Oct 21 '20 at 11:42

I took a more detailed look at dmesg and saw this:

[    0.050136] You have booted with nomodeset. This means your GPU drivers are DISABLED
[    0.050138] Any video related functionality will be severely degraded, and you may not even be able to suspend the system properly
[    0.050141] Unless you actually understand what nomodeset does, you should reboot without enabling it

In the past, I had enabled nomodeset in grub, because Ubuntu didn't boot for whatever reason.

After i removed it and updated grub, everything work fine, as always.

Big thanks to @Alex for helping me with this issue.

Unable to connect other monitors, Lenovo L470

1 Answers1