How to fool a laptop into thinking a monitor is connected? - eviltoast

Hello! I converted an old laptop with a broken screen into a home server, and it all works well except for one thing: when I reboot it (via ssh), if no screen is connected, it will get stuck and refuse to boot. as soon as I connect an HDMI monitor, the fans will start spinning and it will start booting as usual. Then I can remove the HDMI and it will work flawlessly. I don’t know if this is a linux problem, a GRUB problem, or a firmware problem.
Any idea on how to solve this, or on how to fool it into thinking a screen is connected? The problem is not the lid switch as I removed the magnet from the screen, so it thinks the lid is always open

Thanks in advance!

  • tubbadu@lemmy.kde.socialOP
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    10 months ago

    Yes I can ping it!

    Have you disabled the display manager?

    yep, I did `systemctl set-default multi-user.target’

    As someone eles mentioned, boot it with a screen and check the BIOS. Since this was a laptop, the BIOS is certainly expecting a display, so you might have to adjust something there.

    I already looked into the bios but it was pretty empty, just a few options, nothing about displays or graphics card

    but now I have a doubts, perhaps there is a “show advanced settings” button somewhere that I didn’t see? I have to look for it

    • teawrecks@sopuli.xyz
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      10 months ago

      Most likely it’s hard coded in the firmware and not exposed as a BIOS option because the OEM didn’t ever think anyone would run into this. The dummy plug is your lowest effort workaround. Hope that works, good luck!

    • It could be Linux, too. Some distros have fancy boot graphics - look for something called “plasma” - not the KDE one, but a different one - and uninstall or disable that. It’s a common thing that hides the boot log behind a logo-and-progress bar. Arch doesn’t use it, so I haven’t seen it in years, but IIRC it can cause problems on headless systems.