On 15 Oct 2005 14:08:38 -0700, "Cyde Weys"
<cydeweys@gmail.com> wrote:

>So my computer's running fine, and BAM, it suddenly becomes
>nonfunctional. It repeatedly insta-reboots from inside Windows.
>Windows will start successfully, but try using it for a minute or two
>and the insta-reboot occurs. I figured maybe it's a problem with
>Windows, so I tried my Gentoo Linux LiveCD ... not working either. The
>computer boots fine and even sometimes gets the kernel booted, but it
>quickly freezes after that.


So "BAM" really means that it hardly ever crashed (well, it
IS windows, but...) then regular crashing started occuring?
Had anything changed or any events occurred? For example,
moving the system, being inside it, having recently switched
from AC to electric heater in home, BIOS changes, or ???

>
>So I'm thinking it may be a hardware problem. I try memtest86 from
>within the Gentoo Linux LiveCD. I get millions of errors.

Keep in mind that while most of what memtest does is test
memory, there is also the basic function of the system that
has to be ok too, for memory to be stable.

For example, someone brought a motherboard to me that they'd
stabbed with a screwdriver while installing a heatsink.
They knocked off several surface-mount parts around the
board's northbridge. I managed to get new parts soldered
on, and board works, but is now instable above 154MHz memory
bus. I could probably keep trying to resolder or maybe seek
(in vain) specs for the subcircuit but that's beside the
point, that other things can make memory modules seem
malfunctional even if the vast majority of the system works
fine.

>At this
>point I should probably mention that my memory consists of 2X Crucial
>512MB DDR 333Mhz CL2.5 and my motherboard is an Asus A7N8X-X. So I
>think one of my memory modules may be bad, so I try running with just
>one. I get the errors in memtest. I try running it with just the
>other memory module installed. I get the same errors in memtest:
>specifically, the Err-Bits seem always to be 00ff0000.

OK, but, do these errors ALWAYS occur at same address(es)?


>
>Is it possible for two memory modules to both go bad simultaneously and
>in the same fashion?

Remotely possible, maybe, but usually not. It's more likely
the motherboard, physical parts failing or "maybe" a really
bad power supply (less likely).



>I think it may be *possible*, but it's not
>exactly probable. So what could be the problem then? Is my
>motherboard borked?

I would try underclocking to 100FSB, 100Mem, and
conservative memory timings like 2.5, 3, 3, 7. (you will
have to manually set these, the memory may not stay at
CAS2.5 when the FSB is lowered if board is set to Auto or
SPD mode). I don't if this will prove anything but it would
eliminate physically failure in the modules and if the board
is stable underclocked it might provide some aux. use
instead of being thrown away (or is it under warranty)?
Also if you were using Turbo (or whatever it's called) bios
setting for memory, use the more conservative setting.

Also try clearing CMOS, nForce2 boards can sometimes have
wierd bios glitches... if you're running an early bios you
might also try flashing a newer bios but only if you can
regain stablity in memtest86, first. Do not flash the bios
when system is in a state where memory errors are likely.


>
>And just to try to head off a question or two, I checked my BIOS
>settings and the memory timing is set to 333Mhz.

What make/model power supply?

Does CPU use 166MHz FSB as memory does?

Examine board for failed capacitors. A7N8X used "some"
fairly good caps, but I don't remember on the "-X" version,
I vaguely recall it had some component corners cut but I
can't recall for certain which parts). Some of the caps for
the memory are pretty far over towards the right-side edge
of the board, but check the rest too.

Also check the CPU/heatsink thermal interface. If you had
used regular silicone based thermal grease it may have dryed
out over time... had that happen to a system here, so now I
only use synthetic based grease on flipchips. It might be
unrelated but you made no mention of checking temps (or
voltages for that matter) yet. Also check your memory
voltage settings in the bios.