On 4 Oct 2005 10:11:03 -0700, "Peter Carter"
<inet.admin@gmail.com> wrote:


>- The memory
>Well it's Corsair, so it's not as prone to error as say a Generic
>brand. But I have tried each module individually, and the same symptoms
>appear. I would be really surprised that both memory modules blew up at
>the same time (but it's possible).
>AND I tested them with Memtest86. Maybe memtest86 cannot detect all
>types of problems (but I really doubt that).

Often memory problems are not a hard defect in module(s) but
incompatibility due to bios or board design. One can check
this by manually setting different memory timings, BUT, the
odds are quite low that such problems would reoccur on
multiple motherboards and never have errors in memtest86 on
(every) attempt.


>
>- The CPU
>Why would the CPU be the cause of this if EVERYTHING ELSE works fine!
>Maybe it can't handle AGP 8x? I don t know.

CPUs don't "handle" AGP, chipset does. That your CPU works
find with 7500 video is a sure sign it isn't the problem.


>
>- The power supply
>I have an ANTEC 430W. It might not be sending the right voltage to the
>AGP card only?

All of the 4 pin molex connectors merge into same common
rails inside the PSU. The connector used for the video card
will have nearly same voltage as any other- perhaps a
trivially lower voltage due to the video card being a
significantly larger load than anything else running from a
single power lead per 5V & 12V, but still relatively it will
receive same voltage as anything else from power supply.

However, if your connector is loose fitting, it may result
in heating of the contact area and degraded conduction.
Examine the card's socket contacts and those of the power
supply plug. If you have any doubts about them, try a
different plug and clean the contacts on the video card
socket as good as reasonably possible. (wouldn't hurt to try
that anyway).


>
>- The case itself
>The motherboard might be in contact with the case? Other than that I
>don't think the case can influence how the computer runs.
>But I did check for shorts when I reassembled the computer (on changing
>motherboards), and there were none. So the likelihood of the case being
>the culprit is very low in my opinion.

SInce the 7500 video card works, that's unlikely. Since
it's corrupt even on cold boot, overheating of the card is
also unlikely. I would suspect the power supply first even
though it's a decent name-brand. FX5900 is a very power
hungry video card, and while Radeon 9800 Pro is a little
better, it's still no lightweight in that category.


>
>On a side note, my friend John who bought the Same GeForce 5900FX at
>the Same time from the Same store has the Exact Same problem. He also
>has a similar setup to me. Also, the card runs fine on his Pentium 4
>computer!

One thought that comes to mind is that your PSU may not have
sufficient 5V current, as most (maybe all) of the boards
you'd mentioned used 5V for CPU power except the P4 system.
It could be useful to measure 5V (and 12V, 3.3V for that
matter) with a multimeter at the ATX connector and at the
video card connector. Ideally such a system config would
use a trustworthy PSU with a minimum 5V/3V combined rating
of at least 220W, but even then, eventually it could take
it's toll. You might open up your power supply (with AC
disconnected for at least a few minutes first) and examine
the interior, particularly check the output capacitors (near
where the wiring harness connects to the circuit board) for
signs of failure, domed tops or swelling, leaky residue or
even a spot where a capacitor "used" to be but is now only a
bit of paper and foil loose inside. Just don't supply ac
power by plugging it in with the cover off unless you are
confident in your ability to do so safely.


>
>So my question is this. What the Hell could be causing the problem? Has
>anything similar happened to you? If yes, how did you fix it? If not,
>do you have any idea what could be causing it?

Some common things to try are bios settting like disabling
sideband addressing, fastwrites, and reducing AGP rate from
8X to 4X. I have an FX5900 that didn't need any of these
settings changed but they are relatively quick and easy,
"free" things to try.