Actually, it's possible that the noise (which was very faint and probably
wouldn't have been audible with the sides on the case) was
emanating from the HD or HD's, in the same way that they make small noises
occasionally during startup or closedown.

Anyway, as I said in a earlier reply to Mark, I've pulled the Promise card
out and the problem has disappeared.

Which is good (as I solved the spontaneous rebooting) but bad (as I need to
find another reliable source of IDE connections)

Ian Porter
Computer Guys
Arrowtown
New Zealand
[log in to unmask]

----- Original Message -----
From: "David Gillett" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, March 18, 2002 9:27 AM
Subject: Re: [PCBUILD] Flakey PC


> On 17 Mar 2002, at 15:14, Ian wrote:
>
> > Immediately prior to a reboot, there's a little 'Fssst!' noise,
> > very brief and only audible because I have the PC alongside me on
> > the desktop with the side off the case.
>
>   I think this is an important clue.  It suggests:
>
> 1.  A momentary burst of electrical noise on the wires to the case
> speaker, or
>
> 2.  A momentary burst of electrical noise on one of the connections
> to the sound card, or
>
> 3.  A momentary burst of electrical noise on one of the connections
> to the modem, or
>
> 4.  Some kind of arcing or capacitor discharge, with moderately high
> voltage.  And about 90% of the stuff inside the *case* that ever
> deals with >12v is inside the power supply, that's where I'd look
> first.
>
> David Gillett

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