I am trying to connect my Lenovo, Thinkpad laptop with my DELL external screen via HDMI. Either the external screen blinks and shows the colors in very bad quality or it doesn't connect all with "No HDMI signal from your device" message. Laptop runs Ubuntu 21.04.
My external screen works fine via the same HDMI cable with another laptop. Moreover, my Levono, Thinkpad also works fine with another external screen via HDMI.
I have tried so many proposals found in the forums here but nothing helped. Some of the things I tried was disabling secure boot, editing /lib/systemd/system/gdm3.service, restarting gdm3, installing nvidia-driver-435, checking about blacklist-nvidia.conf files, running update-initramfs -u etc etc but nothing worked.
Do you maybe have any idea what is happening? Thanks in advance!
~ $ xrandr
Screen 0: minimum 16 x 16, current 1920 x 1080, maximum 32767 x 32767
XWAYLAND0 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 310mm x 170mm
1920x1080 59.96*+
1440x1080 59.99
1400x1050 59.98
1280x1024 59.89
1280x960 59.94
1152x864 59.96
1024x768 59.92
800x600 59.86
640x480 59.38
320x240 59.52
1680x1050 59.95
1440x900 60.03
1280x800 59.99
720x480 59.71
640x400 59.95
320x200 58.96
1600x900 59.95
1368x768 59.88
1280x720 59.86
1024x576 59.90
864x486 59.92
720x400 59.55
640x350 59.77
~ $ sudo lshw -C display
*-display
description: VGA compatible controller
product: UHD Graphics 620
vendor: Intel Corporation
physical id: 2
bus info: pci@0000:00:02.0
logical name: /dev/fb0
version: 07
width: 64 bits
clock: 33MHz
capabilities: pciexpress msi pm vga_controller bus_master cap_list rom fb
configuration: depth=32 driver=i915 latency=0 mode=1920x1080 visual=truecolor xres=1920 yres=1080
resources: iomemory:2f0-2ef iomemory:2f0-2ef irq:158 memory:2ffa000000-2ffaffffff memory:2fa0000000-2fafffffff ioport:e000(size=64) memory:c0000-dffff
