What's the graphic chip on your pc? You could try plugging both screens in. Then run Monitors
from the menu by pressing Super and typing Monitors. If they are both detected, you can configure them for dual screen use.
![enter image description here](https://i.stack.imgur.com/1bXRq.png)
-- EDIT ---
I just realized I posted this without seeing that you already tried most of these steps. Leaving it up here in case it's useful to anyone.
- Matt
Having been through this recently with a new monitor, I can relate to the frustation of this.
Though I can't offer a solution, I can suggest steps to diagnose.
Diagnosis steps to try:
- check Ubuntu displays settings. (main menu -> settings -> displays)
See if your monitor is recognized there.
Check monitor is recognized by xrandr
:
First
You can check to see if your monitor is detected at all using these commands:
xrandr -q --verbose
You'll get some output that looks something like this:
Screen 0: minimum 320 x 200, current 3840 x 1080, maximum 8192 x 8192
eDP-1 connected primary 1920x1080+1920+0 (normal left inverted right x axis y axis) 293mm x 165mm
1920x1080 60.00 + 59.93*
1680x1050 59.95 59.88
1600x1024 60.17
1400x1050 59.98
1280x1024 60.02
1440x900 59.89
[...]
Somewhere in there, you should see an HDMI connected section:
HDMI-1 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 477mm x 268mm
1920x1080 60.00*+ 59.94
1680x1050 59.88
1280x1024 60.02
If not, there's probably a cable connection problem
See if your monitor can be detected connected to another non-ubuntu machine using the cable adapters you have. If it's recognized there, you know your adapters are not the problem.
Check your video card type: lspci | grep VGA
I found several forum posts suggesting that there is some kind of problem with Nvidia drivers, and sometimes your system is not getting correct resolution information for your particular monitor. The solution there seems to have to do with updating the Nvidia graphics drivers.
Best Answer
Here is a bad way to do this, for most, that may just be good for you.
On desktop, open this file as root
and find this line
and add a this to the end
my whole line is
so I would add it here
Change
lvds-1
for you monitors name, if it is different, find it withSave and exit, and run the command
This will disable the Laptop display for both
grub
and the desktop and force it to the external display, even if you remove theHDMI
cable, the laptop screen will not work. You can remove the change to change it back to using the laptop screen.I can't test this as I don't have a laptop, but I took it from an question at
arch
, where the issue was no laptop display after forcinggrub
to an external monitor.I don't recommend this for most users who want there laptop to still be portable.