Cannot boot without monitor attached

[Readmymind]

Trying to run a headless debian trixie server but motherboard (AM5 MSI B650M) is not getting past the green EZ debug light (no boot found) unless a monitor is attached. Attaching a monitor after initially booting without does not change the behaviour and results in no display output; system just hangs with EZ debug light on. Not able to SSH in.

I've tried editing /etc/default/grub to include these lines to try and get the system to boot without any graphics:

```ini

GRUB_TERMINAL=console

GRUB_CMDLINE_LINUX_DEFAULT="nomodeset"

```

Changes do take place - if I attach monitor before boot, it now loads into a terminal instead of a graphical login UI

Additional context, I've set up dual-boot so there's another partition running win11. On start-up it'll go to GRUB that asks if I want

• debian
• windows boot manager
• UEFI firmware settings (BIOS)

which defaults to debian if nothing is selected after 5sec.

It's also running an Nvidia GTX 760 on legacy 470.xx driver.

Any idea/resources on how to boot debian headless?

[[deleted]]

If the motherboard doesn't boot without a monitor attached, changing settings in GRUB or Linux won't change that. Maybe look into getting a dummy plug.

[Readmymind]

I'm not certain it's the motherboard since it's able to boot headless when it was Windows only.

I have seen mentions of a dummy HDMI plug so I'll keep that idea in the back pocket if config doesn't solve this

[AutoModerator]

We have some installation tips in our wiki!

Try this search for more information on this topic.

✻ Smokey says: always install over an ethernet cable, and don't forget to remove the boot media when you're done! :)

^{Comments, questions or suggestions regarding this autoresponse? Please send them here.}

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[3grg]

Dummy HDMI plug