Random Restarts?

Edward Ruggeri ruggeri at uchicago.edu
Sun May 20 17:35:03 UTC 2007

On Sun, 20 May 2007 11:41:36 -0500, Roland Smith <rsmith at xs4all.nl> wrote:

> On Sun, May 20, 2007 at 11:03:25AM -0500, Edward Ruggeri wrote:
>>  Hi,
>>  My system randomly reboots, usually in the evening.  It is definitely  
>> not a
>>  soft reboot, since the filesystems don't get properly dismounted.  My
>>  suspicion is that it is a heat related issue -- I do leave the computer
>>  running just about all day long, and it has started to get warm.  Then
>>  again, it's coolest in the evening...
> Try and install the mbmon port, and see if it works on your machine. If
> so, start a cron job that appends mbmon output to a file say every 15
> minutes. If it's a heat buildup issue in a monitored component, it would  
> show.
> I wonder though. My machine usually doesn't need a day to heat up after
> a cold start. An hour or so usually suffices.
> Other causes could be a spike in the line voltage due to a large device
> switching on or off nearby. Or an underrated power supply overloaded
> through a cron job.
> Roland

Thanks for the ideas, Roland (and Tamouh)!  I forgot about the possibility  
of power issues.  I do have an Antec power supply, 500W, which certainly  
doesn't mean it isn't the problem, but it _ought_ to be able handle this  

But here's what I get if I run mbmon.

%mbmon -A -t -r 1
TEMP0 : 39.0
TEMP1 : 34.0
TEMP2 : 25.0
FAN0  :    0
FAN1  : 5818
FAN2  :    0
VC0   :  +1.28
VC1   :  +1.50
V33   :  +3.30
V50P  :  +4.97
V12P  : +11.13
V12N  : -11.52
V50N  :  -3.76
Sun May 20 12:32:10 CDT 2007

That CPU temp is at about 97% idle -- high, no?  The voltage on the 12V  
lines seems pretty bad, and especially so on the -5V line.  Should I trust  
the sensors and think about a new PSU?  In the meantime, I'll write to a  
file, and see if it records a dip in power before the next reboot.

-- Ned Ruggeri

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