Debian 12 on Intel NUC freezes without monitor attached

[deepthaw]

I have an Intel NUC I use as my Jellyfin transcoding server (it's old but the integrated gpu works fantastically for it.)

If I don't keep a monitor attached to it, the system consistently freezes after a few minutes to a couple hours. Checking the system logs via journalctl with default install settings shows nothing of interest. I've enabled debug level logging in Jellyfin and it's not outputting anything of interest either. I recall it was doing this prior to me installing Jellyfin as well. I have one of those HDMI dongles that fake a monitor, and that doesn't work either. It has to be plugged into a real monitor.

Device is a NUC8i7BEH.
uname -a : Linux minax 6.1.0-18-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.76-1 (2024-02-01) x86_64 GNU/Linux
lscpu: Intel(R) Core(TM) i7-8559U CPU @ 2.70GHz
lspci: VGA compatible controller: Intel Corporation CoffeeLake-U GT3e [Iris Plus Graphics 655] (rev 01)
I see i915 listed when I run lsmod, but I'm not sure how to more exactly locate the specific drivers.

I've run some short memtest86+ and stress tests and it has no errors or issues reported. I tore it down and cleaned out the fan and replaced the thermal paste. It's happening exclusively when a monitor is not hooked up but I plan on running longer stress tests when I get the opportunity. Neither X/Wayland nor any type of desktop environment is installed.

Any ideas for best next steps to proceed with troubleshooting?

[mrmazda]

Command inxi -GSaz --vs will report most relevant graphics parameters, hardware and software (including drivers), if run from an X session. If it must be run from without X, output will be incomplete, yet helpful. The optimal X display drivers for Intel GPUs can be either of modesetting or intel. You could try switching from whichever is currently employed to the other by either removing xserver-xorg-video-intel, or installing it, then restarting X or rebooting. When X is used, either Xorg/X11, the traditional, or Wayland, the newer, are the two server types usually available. You can try switching to the other at your GUI login screen.

[Aki]

Hello,

You can start the operating system by replacing the "quiet" parameter with the "debug" parameter in the kernel boot configuration, so that it is more verbose in the logs.

If the system "freezes":

1) check if you can access it using ssh from another computer (the ssh server must be installed); if yes, you can inspect or copy logs to another computer

2) check if it responds to "REISUB" sequence (to make a clean shutdown to save as much as possible logs).

Hope this helps.