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I had Ubuntu 20.04.02 LTS installed on my work machine for months and it worked without any problems. Yesterday the power suddenly went out in the office. After it came back and rebooting the machine, I started noticing weird flicking on the screen, in various random parts that it didn't look like a hardware issue. Examples:

  • Disappearing "r" letter in one specific program only.
  • The label of a folder on desktop appearing on top of applications I'm using.
  • Ghost words/lines while typing in terminal.
  • Certain parts in a webpage while browsing appear white, even when I scroll the page, makes me feel like it's a rendering issue.
  • Sometimes the flickering happens on certain windows only, while other applications are rendered normally.

I tried restarting, complete shutdown, changing monitors, changing cables, switching to Wayland, disabling vsync. It's still happening, and it feels like an issue when I have around 4-8 applications opened at the same time.

mohkamfer
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1 Answers1

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I would assume either the graphics driver or the physical graphics card took some damage.

If it's the driver, it could happen via disk problems (filesystem corruption), which is typical after non-graceful shutdowns (like power outages).

I would do this:

  1. would back up all the important data/files from the computer to a safe storage
  2. would run the fsck disk utility to find and correct possible filesystem corruptions (inconsistencies in the data recorded on the disk)
    • while this usually works well, it does not have a guaranteed 100% success rate; that's why the backup in the previous step
    • to check the / system partition, you need to boot from an Ubuntu live installer USB device, and use the "Try Ubuntu without installing" mode (or boot from a system rescue disk or similar); then find and mount your / partition, and run fsck from within this OS instance
  3. if things don't improve after this, I would try re-installing the graphics driver somehow
  4. if things would still not improve, there are still two checks you can carry out "for free":
    • test the RAM for any kind of defects: it's called memtest
      • it's available through a grub menu entry called Memory test, and and may take an hour or two
    • test the internal disk for any hardware-level defects, with a SMART self-test
      • for hard disks it's available e.g. through the disks app's "kebab menu"; for nvme SSDs it's a bit trickier, but legend has it that using smartmontools directly can do it
  5. if nothing was found all through this while the errors persisted, then I would sadly conclude that the graphics card hardware (or the motherboard, even?) took physical damage...
Levente
  • 4,607