# Kde freezes, leds flashing

## dr_Fell

Hello. 

For some time I have problem with my desktop. Sometimes twice a day, sometimes once per week my desktop freezes with two (I guess two on the right) leds flashing. I think it might be connected with HDD, because it seems to happen more frequently when I am downloading torrent files. Under Windows my desktop just reboots - most of the times when new location is loaded in World of Warcraft, and there's heavy hdd usage and cpu and graphic card are waiting for data. Doesn't happen during normal game loading. 

It is possible that these are separate problems (windows is on the old 80GB Samsung drive that is probably dying, Linux on new 1TB Samsung HDD). 

What I know for now:

Memory tested with memtest86+, 7 passes, no errors. 

Graphic card changed - still freezes

PSU changed - still...

HDD changed (250GB Samsung > 1TB Samsung, also tried disconnect 80GB Drive) > still freezes

So It might be CPU or Mainboard, or software problem (in case windows restarts aren't connected with linux freezes - I am moving Windows to new HDD so soon I can see if reboots still happen). 

I need help in diagnosing what exactly is going on with my system in moment of freezing. Any suggestions needed - what logger to use, how to configure logger in order to do not wait and log "on the fly" etc.  At this moment I cannot use netconsole or serial console. 

Also I read somewhere about possibility of configuring special button that can help to take back control of the machine after some kinds of kernel panic and do diagnosis. I can't find this information again.

I have Athlon X2 64@2,67, GF GTX 460, Mobo AliveNF%-eSATA2+, 2GB RAM, Amacrox Warrior 350W PSU. 

I know that this is weak PSU for that configuration, but since freezes / windows restarts occur when there's no heavy cpu or gpu load (and there are no freezes / restarts when playing new games, that use most of the cpu/gpu) I don't think it is problem with PSU.

Sorry for my english. Thanks in advance.

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## palmer

I had similar problems on my machine (I didn't have windows, but the Linux freeze things happened frequently), they were the result of a bad harddisk controller on my motherboard.  You can buy cheap PCI SATA controllers (I see one on newegg for $15), just make sure to check that the chipset is supported in Linux.  I would get a bootable card and then disable the internal SATA in your BIOS.

The key you're thinking of is the "magic sysrq key", it's a setting somewhere in the kernel (google will tell you everything about it).  There is a particular combination you can press that will flush the caches from RAM to disk.  This was useful for me in determining that my disk was bad (the flush would lock the machine, but nothing else I did with sysreq would).

These kinds of lockups can be really tough to track down, if you can find someone with similar enough hardware that you can start swapping out single parts that would make life a lot easier.  If you town has a computer recycling place you could possibly go grab an old IDE disk, PCI video card, and PCI ethernet card -- having these around can make debugging these kinds of problems a lot easier.

Good luck!

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## Aquous

LEDs flashing usually means a kernel panic.

What kernel are you using? Also, do you use the open-source video drivers or binary video drivers?

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## dr_Fell

Hello, thx for Your answers. The crashes happen with many kernels - now I am using 2.6.38-gentoo-r2. I am using binary nvidia drivers (also - many versions, currently nvidia-drivers-270.41.19

In a few days I will compile magic sysrq key into kernel and give it a try. What is surprising for me - now, on a new SATA HDD (the one that had linux on it before), Windows 7 is perfectly stable, I am also downloading torrents using Windows and there are no problems. Could the reason be, that linux is more sensible to hardware problems than Windows ? 

I'll try to debug crashes with sysrq first and ask some friends if they don't have pci-sata controller. You gave me one more idea - I didn't think about ethernet card before, but maybe it is worth checking too. I'll try to use onboard card instead the one I am using now (PCI). 

Thanks

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## cach0rr0

it initially sounded like a hardware problem, especially if you're getting the random lockup/reboot on both linux AND windows

flashing LED's in general on linux, without a response from the system, indicate a kernel panic. 

unless you can capture the text of the panic now that your windows installation is fine, diagnosing what's causing it under linux will be...a challenge at best

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## dr_Fell

Hello, at this moment it seems that my overclocked CPU is slightly losing stability and that could be the cause. Clocked it down about 40 MHz and system seems to be stable. I have found information, that linux is, in a matter of fact, more sensitive to OC, than Windows - just because kernel tries to inform about any errors, when Win just ignores some of them. 

For over 3 yrs it has been working without problems being overclocked, but I guess that slight degradation of some of the components (cpu ? mobo ?) can be the reason, why it doesn't want to work with initial speed. Although I am not sure of it - I could say that some time ago I already tried downclocking (even factory defaults) and without luck that time... Now it seems to work. 

Thanks again for Your help and time.

Michael

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