Diagnosing reboot under load

Michael Lieske micahjon at ywave.com
Mon Nov 7 20:47:14 GMT 2005

> At Mon, 7 Nov 2005 it looks like Micah composed:
>> Alex Zbyslaw wrote:
>>> Bill Moran wrote:
>>>> Bill Moran <wmoran at potentialtech.com> wrote:
>>>>> Micah <micahjon at ywave.com> wrote:
>>>>>> I'm running the i386 version of FreeBSD with 1gb ram.  Didn't
>>>>>> think to  check this before, but I'm getting ~112-113 volts into
>>>>>> the PSU from the  surge strip.  I'm probably going to get a new
>>>>>> PSU today.  The parts  store has a couple of 400 watters in the
>>>>>> $50 range (a fortron and a  thermaltake).
>>>>> Cheap power supplies are a near guarantee that your computer will
>>>>> be unstable.  Unfortunately, $cheap doesn't always == quality
>>>>> cheap.
>>>> I recommend the more recent one as a guage for what manufacturers
>>>> you can trust.  Frankly, if you're only spending $50 on a 400W,
>>>> you're probably getting a piece of junk - although Fortron has been
>>>> rating well in Tom's tests.
>>> A PSU actually capable of 350W *ought* to have done you fine, but
>>> many  cheap PSUs, as Bill says, just don't cut it.  I'd personally
>>> recommend a  Seasonic, which won't be cheap, but will be quiet and
>>> reliable if mine is  anything to go by.  Antec also seem to have a
>>> reasonable rep.
>>> There's a nice wattage claculator here:
>>> http://www.jscustompcs.com/power_supply/Power_Supply_Calculator.php?
>>> --Alex
>> Thanks for the link.  I actually used that calculator when I pieced
>> this  machine together.
>> I'm really beginning to doubt it's the PSU.  Why?  I cannot get the
>> output  voltage to drop no matter what load I throw at it.  I plugged
>> in four  additional hard drives and ran a system stress test and still
>> the voltages  remained rock steady at the values I stated earlier.  I
>> ran it for an hours  with the high-low monitor on a Fluke multimeter.
>> The +5 stayed near 5.1 with  5.08 as the bottom, and the +12 stayed
>> near 11.89 with 11.84 as the minimum.  I even had one of the "random
>> segfaults" and the +12 voltage never dropped  below 11.84.  I'm not
>> sure how I can get the load any higher without using  resistors which
>> most certainly does not simulate the load I'm generating  while
>> compiling.
> Hello,
> How were you using the Fluke meter to test amperage?  I was not
> aware that it would work with a ground line embedded inside the
> power cable?
> I currently have a Fluke-T5-600 and I'm curious about the above
> test.  http://www.tequipment.net/FlukeT5-600VoltageTester.html
> Thanks

I wasn't checking amps because everything I've read says that a bad supply
will show voltage fluctuations.  I just stuck the probes into available +5
and +12 lines (seperate tests) and let it sit in min/max mode for a while.


More information about the freebsd-questions mailing list