Black Screen After Changing Display Resolution

[souzaalexuo]

After changing Lubuntu 18.04 display resolution and rebooting, I will get only a black screen after logging on.

I've tried adding "GRUB_GFXPAYLOAD_LINUX=1280x800" (or other resolutions such as 800x600) to /etc/default/grub file, following this https://askubuntu.com/questions/3515...-login-lubuntu but it didn't work.

"xrandr" will give me "Can't open display".

Does anybody have any idea how to troubleshoot this? (I'm new to Linux)

[Autodave]

A little info on your system may help: especially what video card do you hae, did you install any driver for it, and where did you get the driver from?

[souzaalexuo]

I'm running Lubuntu 18.04 (x64) as a Virtual Box machine on Windows 7 (x64).

Intel® HD Graphics 4000.

I didn't install any driver for it.

[souzaalexuo]

This VM is just a test to me and I could just reinstall the whole thing, but I'd like to take this as an opportunity to learn more. Although I don't understand why Lubuntu couldn't just "not let me" change the resolution to an unsupported one or at least warn me about it.

[wildmanne39]

Thread moved to Virtualisation for a more appropriate fit.

[jorlando]

Delete this file:

~/.config/autostart/lxrandr-autostart.desktop

reboot.

Now retry other resolutions, only press SAVE if the new resolution tests ok (the 15 seconds warning, etc)

If by accident you lose your desktop just remove lxrandr-autostart.desktop and reboot again.

[souzaalexuo]

Delete this file:

~/.config/autostart/lxrandr-autostart.desktop

reboot.

Now retry other resolutions, only press SAVE if the new resolution tests ok (the 15 seconds warning, etc)

If by accident you lose your desktop just remove lxrandr-autostart.desktop and reboot again.

Tank you, jorlando, but I've already deleted the VM.