[Gllug] Mysterious reboots

[Paul Rayner]

On 4 Apr 2006, at 12:53, will wrote:

> Hello.
>
> I hope someone here has some idea of what the problem with my computer 
> is, I have no idea.
>
> I have a new machine at work (AMD Athlon(tm) 64 Processor 3200+, 2Gb 
> dual channel memory).  It was working fine for a few weeks but now I 
> have a really big problem.  Seemingly at random the machine hangs for 
> about 10 seconds (frozen display) then reboots (not a graceful reboot, 
> just back to the BIOS).  Sometimes it goes for hours without this 
> happening (it stayed up all last weekend), and sometimes it will 
> reboot frequently (10 times yesterday).
>
> As I mentioned, it was working fine.  Some things I had considered 
> might have contributed to the problem, ie. the machine was fine before 
> I did these things:
>
> 1) I upgraded to FC5 from FC5 test3
> 2) I moved /home from /dev/hda<something> to a software raid mirror 
> consisting of /dev/sda2 (SATA) and /dev/hda1
>
> I have now reversed 2) and he machine has since crashed/rebooted.
>
> Also I have also considered the following possible causes:
>
> 1) Overheating?: however lm_sensors indicates the temperatures in the 
> case/CPU to be a fairly constant 32 deg/c
> 2) Lack of power?: reboots have happened during prolonged periods of 
> CPU idleness and the machine only has a low-spec gfx card and two HD's 
> in, the 400Watt power supply should be able to cope.
> 3) The power in the building could be crap: however no-one else in the 
> building seems to have these problems
> 4) My power supply may have developed a fault.
>
> A colleague has a machine with the same CPU and two HD's in it and has 
> had no problems (although he is running 32bit windowsXP), and no-one 
> else in the building is reporting problems.
>
> The last reboot I had was about 12:00 midday, the one before that 
> about 6:00 PM last night.  Yesterday the machine rebooted about 10 
> times.
>
> Can anyone suggest any things I should test for or what could be 
> wrong?  It seems to me to be a hardware fault, but I could be wrong.  
> Has anyone else experienced these sort of problems?

If you haven't already, I'd try the following (easiest first).

1) Change the power cable (kettle cord) - it could just have a 
loose/bad connection
2) Try plugging a different machine into the same power supply and see 
if that machine starts rebooting
3) Check all the fans are spinning properly
4) Unhook the "reset" button if it has one - unlikely but simple and 
eliminates a dodgy connection there.
5) Try removing all cards/peripherals
6) Try swapping the power supply
7) Take a full backup and send it back under warranty?

I had a machine which was doing this at a customer site a few weeks 
ago, and tried 1-6. None of them solved the problem. It was an old 
machine, so the disks were removed and put in another machine instead.

HTH,

Regards,

Paul


--
Paul Rayner
Ylem Solutions Ltd ~  4-14 Tabernacle Street, London. EC2A 4LU
Office: 020 7074 0220 ~ Mobile: 07739 143 763 ~ 
Paul.Rayner at YlemSolutions.com

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