Your problem may have something in common with a situation which I've
experienced several times.  I intended to report it to the group anyway, as
it might help someone else, so now is as good a time as any.

For a lot of the new PC's I build, I've been using Gigabyte motherboards,
and two of the most recent models are the GA-7VKML and the GA7VKMLS.

Both of these boards employ thermal cut-out circuitry, so that if the
temperature of the CPU sensor approaches a pre-determined maximum, power
will be disconnected.

My usual CPU is an AMD Athlon 1800+, and when I purchase these from a local
distributor, they come boxed in a plastic display pack, rather than a simple
OEM packet, along with a heatsink and fan, and the whole kit is sourced
directly from AMD.

The first of the 7VKML boards that I tried, using the Athlon 1800+, just
wouldn't boot up.  It would run for a few seconds only and then stop. After
trying everything I could think of to, without success, I returned it to the
distributors, who were unable themselves to suggest a fix but sent me
another.

The replacement did the same but came to life the following day.

Several subsequent boards have also been troublesome.  However, we've just
managed to discover the source of the problem.

It originates here:
The AMD boxed CPU comes complete with a heatsink.  Attached to the heatsink
is a square of thermal paste - it's a pink material and quite thick.

So thick, in fact, that it actually prevents the CPU from being properly
cooled until it's been running long enough for the paste to thin out.
Consequently, within a few seconds of being switched on, the CPU temperature
will exceed the preset BIOS cut-out level causing the power to be shut off.

The solution is simple - remove the CPU and heatsink, scrape off the
OEM-supplied thermal paste, and apply a thin smear of normal paste.

Considering that the BIOS pre-set is 105 degrees C, which is it's upper
limit, this certainly demonstrates the volatility of the CPU, and the need
for adequate protection against the failure of a cooling mechanism.

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

> From: "John Long" <[log in to unmask]>
> >  I have a A7V333/Pa/Raid/u/139  Asus motherboard. It will not power on.
> > I have tested the powersupply with a ATX PS tester all ok. I have tested
the chassis for excess leakage in Uamps with no high
> results. I Run the PS with the atx ps tester and all is ok I hook up the
Mother board and it runs for 3 seconds then dies leaving
> the light on in the right hand corner of the Motherboard.

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