cause of reboot

Michael Powell nightrecon at
Tue Oct 1 00:32:54 UTC 2013

kpneal at wrote:
> While we're throwing ideas onto the table let me mention power supplies.
> Power supplies and hard drives are in a race to see which one will fail
> first. It may be that the power supply is marginal and added load from
> the drives being hit hard may send it over the edge. How heavily loaded
> is the machine in question?

Absolute and total agreement with this. As they age and the filter caps leak 
and dry out more it will eventually become apparent. But in the meantime the 
output DC can just about meet spec up until really loaded. Then the ripple 
becomes so excessive it's not quite "DC" any longer. You can clearly see it 
using an oscilloscope. 

The 0300 AM periodic does hammer a machine enough to possibly push a 
marginal power supply over the edge. I once had a box where the RAM chips 
would "sing" with a high-pitched whistle only during the 0300 periodic run. 
It sounded just like the horizontal output on a television right before 
destruction.  :-) 


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