I upgraded my old computer and weird things have started happening. I successfully installed Debian and everything seemed to be fine but in a few days I noticed that after ~10 hours of work the display started showing different colors instead of the image ( I can share the video if it's of any interest). When I pressed the button to turn it off the normal console appeared and there was nothing wrong in logs after the reboot (Maybe I don't know where to look?)

I connected the display via DVI (instead of VGA as It'd used to be) and instead of showing different colors the monitor started blinking randomly. During blinking and showing different colors other services usually (but not always) seemed to work fine (I'm using this computer as a hotspot 24/7).

After the last episode I noticed this in /var/log/syslog

Feb  8 19:57:36 STARSERVER kernel: [74245.109792] ata5.00: ACPI cmd f5/00:00:00:00:00:00 (SECURITY FREEZE LOCK) filtered out
Feb  8 19:57:36 STARSERVER kernel: [74245.109793] ata5.00: ACPI cmd b1/c1:00:00:00:00:00 (DEVICE CONFIGURATION OVERLAY) filtered out
Feb  8 19:57:36 STARSERVER kernel: [74245.122214] ata5.00: configured for PIO0
Feb  8 19:57:36 STARSERVER kernel: [74245.123513] ata5: EH complete
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Feb  8 21:15:26 STARSERVER kernel: [    0.000000] Initializing cgroup subsys cpuset
Feb  8 21:15:26 STARSERVER kernel: [    0.000000] Initializing cgroup subsys cpu
Feb  8 21:15:26 STARSERVER kernel: [    0.000000] Initializing cgroup subsys cpuacct

I suppose that at 19:57 computer hung (I noticed that because Wi-Fi disappeared). When I turned the monitor on the computer didn't react on any actions.

OS: Debian sid Configuration: B85m-D3H motherboard with i5-4570 on board.

  • @illuminÉ the first thing I though of was the temperature. but it seems it's not the issue here. the temperature can reach up to 60C max. Feb 8, 2014 at 19:36
  • It's possible as explained in the answer that tracking down the issue might represent a greater time investment than reinstalling. Because indeed you do not know if it's the update or a device failing per se in this case... Maybe make a fresh install in a different location and if you can ever isolate the problem you might be able to apply a solution to your current setup down the road...
    – user44370
    Feb 8, 2014 at 19:43

3 Answers 3


Weird, non-reproducible crashes and corrupted file contents is a common symptom of bad RAM. RAM can fail over time. Run a memory test: reboot into Memtest86+ and let it run for at least one full pass, overnight if needs be.

If you see a file where a single bit is corrupted and only in positions whose differences are a multiple of 4, that's a telltale sign of bad RAM. But the signs aren't always as clear.

  • I'd already done it before posting here. memtest has given nothing. Feb 9, 2014 at 13:02

the issue with your display sounds like the video port and/or chip may be having a hardware failure. Unfortunately the only way you'll likely be able to diagnose this set of problems is to start at the beginning with a wipe and re-install. It's going to be difficult if not impossible to diagnose the issue beyond that.

You could spend a lot of time trying, but you'll likely get no where with it, except waste a lot of your time. Generally with situations such as this, it's best to just reset to a known state where things should work, and then diagnose from there.

  • The first OS I installed was Windows 8.1, where I was greeted with a BSOD (CLOCK_WATCHDOG_TIMEOUT). Maybe it could be some help? Feb 8, 2014 at 19:44
  • @enter_the_bot - see here: msdn.microsoft.com/en-us/library/windows/hardware/…. There are steps mentioned there for how to recover from that error. That is beyond the scope of this site however, since you're now moving us into a Windows 8 issue, which isn't what U&L is meant for.
    – slm
    Feb 8, 2014 at 19:47
  • @enter_the_bot - did you already try it then?
    – slm
    Feb 8, 2014 at 19:50
  • The debian related issue bothers me more. I've mentioned the Windows related problem just to give a little more information Feb 8, 2014 at 20:00
  • @enter_the_bot - I would tend to agree with that. However when encountering multiple issues such as this with a system, I try to eliminate as many variables from the situation as I can, to help simplify the remaining ones 8-)
    – slm
    Feb 8, 2014 at 20:04

If the machine starts misbehaving after running for a while and finally hangs, you might have overheating problems. Check air intakes/exhausts, clean out lint, check the fans are working, replace heat paste on CPU.

  • In the comment section below my question, I said that overheating was not the problem here. Feb 8, 2014 at 20:58

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