Re: [Hampshire] [OT] [hardware] Dead machine?

Hugo Mills <hugo@???> wrote:
> On Saturday morning, the machine crashed.
> Nothing appeared in the logs. On trying to
> restart it on Saturday night, the machine
> wouldn't come back up at all (no POST), but the
> case fan started when the machine was plugged in
> (which it normally wouldn't do).

Is the case fan powered from the motherboard?

> This morning, it did the same thing, and so far
> hasn't come back, despite being unplugged from
> everything for some time. The only thing that
> seems to be "working" is the case fan -- which
> is permanently on when the machine has power.
>
> I'll be speaking to the vendor tomorrow about
> this, but has anyone else seen this sort of
> behaviour?

Yes, it seems to be an occasional failure mode of
recent motherboards. Recent being Socket 370/462/
478 - we haven't seen anything newer at Jamie's.

I don't think we've seen it on old boards, but I'm
not that closely involved in the workshop any
more.

I don't think we've come up with a diagnosis.

> Is the motherboard completely shagged? If so,
> why did it run fine for 12 hours or so last
> night after its first failure?

I think I'd suspect some non-fatal damage to the
board, possibly affecting the power line
regulation. It sounds like your problem is
intermittent, but it may be progressive as well.

If the case fan is powered by the motherboard, I
suspect it's under software control. The fan
controller may default to supplying 12V to the
fan, until it's programmed to a lower voltage. If
the processor is crashing before the BIOS gets
that far, the supply will stay high and the fan
will continue running.

Have you tried the keyboard lights trick?

Nick.

--
Nick Chalk ................. once a Radio Designer
Confidence is failing to understand the problem.