Changing the screen resolution

2 respostas [Última entrada]
lcotton
Desconectado
Joined: 10/27/2018

System:
Thinkpad 400 Laptop
OS: Trisquel 8, Based on Ubuntu 16.04 LTS
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Hi

The screen on my Thinkpad 400 laptop is broken, so I have hooked it up to an external monitor - Philips 226E9Q, via VGA.

When I did this I noticed the screen resolution settings were incorrect, so I could not see the whole display.

I have managed to correct this by using the following commands:
# check aavailable outputs and modes
$ xrandr -q

''''
lists outputs and modes one of which is VGA1 / 1920x1080
....
# set required mode for VGA
$ xrandr --output VGA1 --mode "1920x1080"

Doing this allows me to see the whole screen, however this needs to be done separately for every user - the setting is not global.

Having set the resolution I can see the menus and can now try to use the GUI to set the resolution.
I go to ControlCentre->Display where in theory I can set the resolution, but the list in Resolution field does not give me the option of 1920x1080 (even though xrandr lists that mode).

Does anyone know how I can add the required mode to the list presented in the Display dialog ?
(dialog has a 'Apply system wide' button which I'm hoping will set it globally when I can select the mode)

Failing that (or actually as well) does anyone know how I can set the resolution globally from the command line ?

Also does anyone know where the resolution settings are stored ? Presumably there is a file or something I can edit to set them manually.

nadebula.1984
Desconectado
Joined: 05/01/2018

Which firmware does your T/R400 use? Does it have ATI discrete graphics?

If your computer uses original BIOS and has discrete graphics, go to BIOS settings and disable the discrete graphics. You need to set "Display Device" to "Integrated" and "Switchable Graphics OS Detect" to "Disabled".

For 4-series chipset based ThinkPads, disabling the discrete graphics (on T/R400 or T/W500) also disables the DP port (which supports only discrete graphics output). But there is no DP on T/R400 so you won't lose any functionality.

Magic Banana

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I am a translator!

Desconectado
Joined: 07/24/2010

I believe https://wiki.ubuntu.com/X/Config/Resolution answers everything you asked.