I use a 4GB raspberry pi 4B. Recently, I switched to Ubuntu, and it had been working fine, until one day, I booted it up and the screen was black. Sometimes a glitched Ubuntu loading screen appears before a black screen, only containing a blinking text cursor which I can’t interact with. I’ve tried using terminals with alt + f(n), but, for some reason, I can’t write out files that allow to resolve the issue. I’ve tried modifying some lines in the config.txt file, like hdmi_safe, hdmi_force_hotplug and hdmi_force_output, but nothing works. Can anyone please help me?

  • 1
    Just restore from your backup.
    – Milliways
    Commented Sep 8, 2023 at 22:37
  • If you can see a cursor, then it's unlikely a HDMI config change will fix anything, since HDMI is not broken. did you try Ctrl+Alt+f(n) instead of just Alt+f(n) as for until one day ... what happened the previous day? probably some Ubuntu update? Commented Sep 8, 2023 at 23:35
  • Ctrl+Alt+f(n) seems to do the same thing. However, when I did that after holding the up and down arrows while it loaded, the Ubuntu loading screen appeared. Then, an error popped up saying “[FAILED] Failed to start snapd.failure.service - Failure handling of the snapd snap”. As for the day before, I had been running some terminal commands, specifically opencv build, and changing some Geany settings. I don’t know whether it got updated, but I reckon I just unplugged it. Commented Sep 9, 2023 at 9:12
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    this site is not a forum ... please add all information to the question ... do not use comments
    – jsotola
    Commented Sep 12, 2023 at 1:07
  • The question doesn't seem to be editable, and I didn't believe that what I'd done before would be so important, since many people reported having this problem right after Ubuntu updates. Commented Sep 15, 2023 at 14:13

1 Answer 1


I managed to resolve the problem. Given that I was unable to rewrite files, I started by doing sudo mount -o remount,rw /. Then, I did sudo dpkg-reconfigure gdm3 and sudo service gdm3 restart. Immediately after that, my desktop appeared. However, now I have to do this every time I want to boot up my Raspberry Pi, so if anyone knows how to solve the rest, that would be helpful.

  • I was trying to make an autostart file and when I rebooted, a black screen with the mouse cursor. I tried many different keyboard with no results. When I right clicked with the mouse, several options appeared, one was a terminal, which I used to correct the autostart file.
    – bstipe
    Commented Sep 16, 2023 at 22:22

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