I am trying to connect an external monitor to my Thinkpad T540p. OS is Xubuntu 18.04, monitor is a Dell U3011, I am connecting the monitor using a HDMI -> Mini Displayport cable.
Unfortunately my Thinkpad does not recognize the monitor at all. I tried a lot of the steps from this thread.
1a) Switch default display manager to lightdm / gdm3
I tried multiple times to switch it back and forth, no change
1b) Hoping it's still connected to the display manager, I updated xfce4 to 4.14 and additionally tried out Wayland
Unfortunately no success either
2) Reinstalling drivers
sudo apt-get purge 'nvidia*'
sudo add-apt-repository ppa:graphics-drivers
sudo apt-get update
sudo ubuntu-drivers autoinstall
This didn't work, the graphics chip in the T540p is made by Intel anyway I think?
3) Trying some xrandr settings
a@a-T540p:~$ xrandr --addmode DP-1 1920x1080
a@a-T540p:~$ xrandr --output DP-1 --mode 1920x1080
xrandr: Configure crtc 1 failed
Didn't work obviously.
xrandr output after reboot:
a@a-T540p:~$ xrandr
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 8192 x 8192
eDP-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 344mm x 194mm
1920x1080 60.01*+ 59.97 59.96 59.93
1680x1050 59.95 59.88
1600x1024 60.17
1400x1050 59.98
1600x900 59.99 59.94 59.95 59.82
1280x1024 60.02
1440x900 59.89
1400x900 59.96 59.88
1280x960 60.00
1440x810 60.00 59.97
1368x768 59.88 59.85
1360x768 59.80 59.96
1280x800 59.99 59.97 59.81 59.91
1152x864 60.00
1280x720 60.00 59.99 59.86 59.74
1024x768 60.04 60.00
960x720 60.00
928x696 60.05
896x672 60.01
1024x576 59.95 59.96 59.90 59.82
960x600 59.93 60.00
960x540 59.96 59.99 59.63 59.82
800x600 60.00 60.32 56.25
840x525 60.01 59.88
864x486 59.92 59.57
800x512 60.17
700x525 59.98
800x450 59.95 59.82
640x512 60.02
720x450 59.89
700x450 59.96 59.88
640x480 60.00 59.94
720x405 59.51 58.99
684x384 59.88 59.85
680x384 59.80 59.96
640x400 59.88 59.98
576x432 60.06
640x360 59.86 59.83 59.84 59.32
512x384 60.00
512x288 60.00 59.92
480x270 59.63 59.82
400x300 60.32 56.34
432x243 59.92 59.57
320x240 60.05
360x202 59.51 59.13
320x180 59.84 59.32
VGA-1 disconnected (normal left inverted right x axis y axis)
DP-1 disconnected (normal left inverted right x axis y axis)
HDMI-1 disconnected (normal left inverted right x axis y axis)
DP-2 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)
Shows the Displayport as disconnected :(
I don't know what to try next. The monitor is definitely working, I tested this with another computer.
Any hints on how to further debug this are appreciated! Thanks in advance
