[Tfug] Power Problem (slightly OT)

[Jim Secan]

Thanks for the suggestions.  I put in a completely new PS with no change
to the behavior.  I'm fiddling around with the switches to the front panel
now to see if they're munged in some way.  I try those of your suggestions
I think I'm capable of doing.

I know what caused the lockup, and it wasn't hardware related unless the
hardware died exactly when the software would have taken the OS south. 
The Linux shutdown process proceeded normally after I hit the power-off
switch, so the kernel was still functioning at that point and the hardware
appeared to be behaving itself.  It was just when I tried to power back up
that I discovered I'd magically turned a server into a boat anchor.  I
should perhaps try to get a job with MS.

Jim

Choprboy wrote:
> On Tuesday 22 January 2008 12:52, Jim Secan wrote:
>> I had to power down my server to recover from a lock-up (long story).
>> Once it was powered down, nothing I did would entice power to come back
>> on.  No sparks, no burning wires, no noises, just no power to anything.
>> Tried all combinations of switches and plugging/unplugging with no
>> change.
>>  Tried new power cord, different outlet, no change.  OK.  Just went
>> through the joy of replacing the power supply.  Same behavior.  I'm at a
>> complete loss as to what's going on.
>
> Well.... given that it is an ATX powersupply, the front power button may
> not
> actually do anything other than send a signal to the motherboard BMC which
> should always be powered off the +5Vsb rail. There are really only 2
> possible
> components at fault; the power supply itself has died (possibly kaput or
> the
> +5Vsb rail is dead) or the motherboard has a problem (died completely or
> the
> BMC is locked up).
>
> I would first start by completely removing the power cord and let it sit
> for a
> few minutes to discharge, then plug it back in. If the BMC is locked up,
> that
> should reset it (as it never otherwise powers off).
>
> Second, I would check the +5Vsb rail with a voltmeter, I think its the
> purple
> wire, but don;t remember off the top of my head. That should have +5V on
> it
> at all times (when plugged in), if it doesn;t then the PS is kaput.
>
> Third, and finally, if the above all checks out, then I would momentarily
> (a
> second or so) ground the PSON wire (green I believe) with a paperclip to
> one
> of the black PS ground wires. This should cause the ATX power supply to
> turn
> on. If it does turn on, then it sounds like the motherboard has lost its
> magic smoke (which might coincide with your lockup). If it doesn't turn
> on,
> then your PS has a fault.
>
> Adrian
>
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