Lubuntu live/install iso not usable on external screen


I just installed 19.10 on my desktop and found the installer GUI very well designed, clear and simple to use.

I want to install it on an old HP laptop which has a broken screen. I use it attached to an external monitor via the VGA cable output.

This presents two problems. I can’t see the BIOS or GRUB menus, but it is already configured to use CDROM if present and as long as I don’t need to interact with the GRUB menu, it’s fine.

Since I know what is presented having used the install CD on the desktop PC, I know it will auto detect the language and proceed to installer after 30s.

The trouble is when it finally boots to the Lubuntu desktop it is mis-scaled and I only get just over half the screen horizontally. ( I just about see the “1” of 19 behind the birdies and Lubuntu gets cropped to “buntu” )

If I fly blind , I think I can hit down arrow and boot to “safe” mode but this seems to be based on 18.10 and shows nothing on screen. If I do this on my desktop it gets stuck half way and does not even boot to an emergency console. ( So much for “safe” mode ).

I worked out that if I boot to 19.10 , I can select the invisible ( off screen ) installer icon by clicking on the desktop and hitting the down arrow. Enter-key then fires off the installer. Sadly this shows nothing of the installer and I remain on the desktop.

I’m guessing / divining that the installer is running off the ( broken ) framebuffer output, however setting up the partitions is an operation far too complex to do flying blind.

Now such things usually have tweaks and command line options, it is possible to run calamares installer directly from a terminal window with suitable options in order to avoid interacting with the broken framebuffer output?

Thanks for any guidance.

Welcome @lubu

By far the easiest fix to this is available on many laptops, and involves changing settings in BIOS. On some devices the option is available to make the external display the primary screen, including the only used display. The OS just obeys this once booted as it’s what the hardware/firmware reports the system has available.

Most laptops have a key to have the image switch between display options (ie. use internal only, external only, mirror displays, both displays but un-mirrored) which can be used to allow you to make BIOS/UEFI settings using the external display.

This is what I’d try first.

I was aware of setting the primary display in BIOS but since I can’t see it , I was not able to do that.

Many thanks, I was not aware of that, I will have to look into it. It really is skating on thin ice not having access to BIOS on this machine.

Will that key work all the time or just during BIOS booting time?

How and when it works is BIOS/UEFI specific (ie. firmware in your box).

Many boxes have capacity to make it work all the time so a change there impacts OS booted & used (esp. when made in settings in the bios itself).

In testing before I replied, using a within-reach thinkpad x201, I used fn key (fn+F7 on my thinkpad) and it does impact further boots until the external display is disconnected; however it had no impact on my booted Lubuntu 20.04 LTS system (today’s daily booted for testing purposes) The key combination is to make BIOS/UEFI readable so you can make the change permanent in BIOS itself (if available, I had a look in the x201 BIOS & I didn’t see the option to use only external display, but I’ve used it before on thinkpads & dell laptops)

On one dell latitude, it saved the thing from being recycled because it’s display became annoying once it got warm so I made it use external only & the box was good awhile longer (I used external keyboard & mouse so the turned-off screen wasn’t always in the way; ie. it was used with the lid closed)

Thanks for taking the time to test explicitly. I’ve sent a request for model info since I have the added problem that this box is maintained remotely.

As another possible workaround you could use runner ( Win + R)on the screen you can see. From runner type in monitor and it should narrow the search to monitor settings. Once the monitor settings launches you can make adjustments to disable the broken screen.

HP G60-312EM : no magic buttons, no BIOS setting for default primary video out. :frowning:

So back to square one needing a means to run calamares with output otherwise than framebuffer ( which I’m still having to assume is what it is using by default.

I’m sorry but I don’t know enough to help with your issues with Lubuntu’s installer calamares; some of which I suspect is assumptions by its developers who assume you have working screens.

In your case I’d probably install using the Ubuntu Network installer (see below for link) as it is bound to text (debian installer I believe) and thus should display on both monitors. Once you’ve installed a basic Ubuntu system (without desktop), I would add the ‘universe’ repository and then install lubuntu-desktop

I can’t think of anything you’ll be missing, or anything extra given this method of install, but it’ll be very close (and in the end, very few of run vanilla installs with no customization)

Thanks for that suggestion.

I agree that assuming working hardware is not too unreasonable though it’s hardly always the case. I’m sure I’m not the only one with a laptop with a dead battery or a screen which is damage or no longer has a working back light.

Assuming the only reason there is an external screen present is because someone want a dual monitor setup is less reasonable.

I would expect there is some configuration option for calamares which can force this to use the secondary display. I may try opening an issue on calamares.

Now I’ve realised this is a split display being used, it seems likely that it is using Xserver, not the framebuffer , as I originally thought. So I may be able to get to see the installer somehow.

thanks for your help so far.

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