"Jonesgold" said:
Ran Memtest86 and no problem
PC reboots when no load and heavy load.
Ran Prime95 and the +12 volt is running between 13.4 -13.6 CPU temp. got
up to 129F
Reboot does not seem to be related to VIDEO activity.
Have you checked here ?
http://www.asus.it/support/cpusupport/cpusupport.aspx
It says the board needs a "FSB333" sticker on the Northbridge.
That, and BIOS 1011.
The following review doesn't make any mention of issues, implying
that FSB333 isn't a big deal.
http://www.lostcircuits.com/motherboard/asus_a7v8x/
As you've run memtest and feel the memory is OK (and memory is in
slot 1 and slot 3 ?), the only other things I can think of, are
to improve the Northbridge cooling (CMOS slows down as it gets
warmer), or adjust the S2K bus settings. The S2K setting is the
drive strength setting on the processor FSB, and the drive strength
setting affects the signal quality and signal speed. Unfortunately,
these two factors move in opposite directions, so as you crank
up the drive strength, the signal edge rates get faster, which
can improve setup time, but at the expense of more reflections
on the bus.
As for which direction to adjust, I think the defaults on N and
P are 2 and 3. I would write whatever setting you find, on a
piece of paper, so it can be restored later. Then change both
P and N settings by 1, and test for a while, to see if there
is any change. It will be easy to see a negative change (crash
almost instantly), but positive changes will take a lot longer.
Generally speaking, when crashes happen less frequently than once
a day, it takes a hell of a long time to determine whether you
are improving things or making them worse, with different
settings.
Also, your +12V is rather high (12.6V is +5% and is the usual
spec for the PS), but I don't really know whether Vcore on the
board runs from +12V or +5V. If the board was using +5V, and the
PS responds to a heavy load on +5V by cranking the primary side,
this can cause other, less loaded outputs, to jump up, and that
could account for the high reading. On Pentium boards, you'd
expect to see the opposite - +12V drooping, and some other
voltages elevated. I wouldn't worry about that too much - if
you have a multimeter, you could check all the voltages with
that, and see which way they are leaning. The only PS output
with tight regulation is +3.3V, as there is actually a feedback
wire on the ATX 20 pin, to tell the PS whether the +3.3V is
high or low. There is a pin on the ATX 20 pin connector with
two wires on it, and the thinner wire is the feedback wire.
Good luck with your hunt for stability,
Paul
