PC is connected through SSH but shows no screen output.
PC is connected through SSH but shows no screen output.
I have an unusual setup that required expert advice. My PC features an i5-8400 CPU, an ASUS GL12CP prebuilt board, two 16GB RAM modules, and a newer Corsair CX650M. On the M.2 SSD I'm running Debian 13. Two weeks ago I installed Debian 12 at my desk with the monitor connected, then later moved it upstairs to a network closet where I upgraded to Debian 13. After that, I started experiencing SSH connection drops and couldn't see any display on any monitors using HDMI cables, even with the integrated graphics. The splash screen disappeared completely, but I could still access the system via SSH. Network issues seemed likely due to a faulty cable, as the problem resolved when I returned the device to my desk. I've tried booting with one RAM stick, removed the CMOS battery, used a dedicated GPU, and even reset it, but nothing displayed. It's hard to say what's wrong—possibly hardware failure or something overlooked. I'm unsure where to begin; maybe assume the worst and consider the PC is now headless. Help would be greatly appreciated.
did you ensure an update and full upgrade to the newest version of everything? there could have been issues during the process. you might want to try installing rustdesk or anydesk and set up unattended access so you can manage it through the GUI. it could help identify problems, maybe even something as basic as a broken X server. if needed, you can reinstall ubuntu server with the GUI for a better experience than Debian, though i have a bias toward rolling release distros and don’t like Debian.
I followed this manual to improve my setup, but Debian handles updates differently than Ubuntu and others do it, so it should have worked just by switching to the new repository. It might have helped if I tried that installation to diagnose the issue better. For Ubuntu, I used to run it until it became problematic during a full upgrade. Eventually, I chose Debian because it offered quicker startup and a lighter system for my needs.
If you haven't already, set up aptitude. It provides a basic text-based interface for managing packages. After installing, use / to enter your search terms, xserver-xorg-core works well as a starting point. Press enter and verify installation. If missing, install it. You can also choose a desktop environment like Gnome, Mate or Cinnamon, which typically installs Xorg automatically. Pressing q then y will close aptitude and restart the system. It's worth noting that running a desktop environment on a server increases its exposure to external threats. This is likely acceptable if the server remains within your local network, but becomes a concern if it can be accessed from the internet.
It could help to check the BIOS for an option that always shows via a dGPU. You should be able to switch it to use the integrated graphics instead, unless you require a dedicated dGPU for rendering. If that fails, unplug all storage and OS drives, install a basic SSD, and run Win-OS to test if the graphics work. This suggests the hardware is functional but the problem lies with Debian. You might try using Win-OS on a reused disk to install Debian12, which previously worked for you. Another option is Devuan—a Debian-based distro without systemd—though you likely won't notice much difference compared to standard Debian.
Well as said in the original post, can't even see the splash screen, and as a follow up to that no display in bios either, so I can't really do much, as I also said in the post I couldn't even get it working with a dGPU, also since it's a prebuilt bios it's very lacking and has no such option when I checked before, but then it also worked via iGPU. However I do think I will try to take out the SSD in case it's something with grub that messes the pre boot environment up, and if that's the issue I will just wipe that and reinstall.