PC100 CAS2: 256MB - VS - 128MB X 2 ???

I have a 'sudden' 'random' reboot issue w/ my ABit ZM6 system (i440ZX
chipset, Celery OC'd to 550, FSB100).

It has happened twice in the last 2 days but it's one of those things
that may be OK for several days or a week or better.

This has never been a problem for the 1st few years I've had this
system. But I'm leaning towards a h/w problem. A couple months ago I
installed a second 128mb stick (both are from Mushkin) and that more
or less coincides with when this problem started. But the problem can
be so darn intermittent and it's been quite a few months now so it's
hard for me to be specific. (And if I have to keep pulling h/w every
couple week to isolate - it could take months!)

I read somewhere a while back (cant' find it anymore) that a singel
256 stick is better than 2 128s and can avoid h/w problems like
this...?

Soooo... memory?

Other possibilities? Power supply? CMOS battery? I dunno where some
logical places to start might be...?

Thanks!

---

I know some folks might suggest the OS or virus etc...
Background: I've done one fresh install of 98SE recently and just last
week I wiped everything and did 2K Pro. None of this seems to really
impact it. Between fresh installs from scratch and AV and firwall s/w
I don't see this as a likely s/w problem. In both cases I completely
wiped the disk and installed from scratch...

just as a test, run the system with just the one stick and then the other
stick of ram and see if it is stable with both by themselves. if it is,
then it is likely an interaction between the sticks of ram and maybe if you
talk to Mushkin, they might help you out with the issue.

--

Thomas Geery
Network+ certified

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"foobar" <> wrote in message
news:...
>
> I have a 'sudden' 'random' reboot issue w/ my ABit ZM6 system (i440ZX
> chipset, Celery OC'd to 550, FSB100).
>
> It has happened twice in the last 2 days but it's one of those things
> that may be OK for several days or a week or better.
>
> This has never been a problem for the 1st few years I've had this
> system. But I'm leaning towards a h/w problem. A couple months ago I
> installed a second 128mb stick (both are from Mushkin) and that more
> or less coincides with when this problem started. But the problem can
> be so darn intermittent and it's been quite a few months now so it's
> hard for me to be specific. (And if I have to keep pulling h/w every
> couple week to isolate - it could take months!)
>
> I read somewhere a while back (cant' find it anymore) that a singel
> 256 stick is better than 2 128s and can avoid h/w problems like
> this...?
>
> Soooo... memory?
>
> Other possibilities? Power supply? CMOS battery? I dunno where some
> logical places to start might be...?
>
> Thanks!
>
> ---
>
> I know some folks might suggest the OS or virus etc...
> Background: I've done one fresh install of 98SE recently and just last
> week I wiped everything and did 2K Pro. None of this seems to really
> impact it. Between fresh installs from scratch and AV and firwall s/w
> I don't see this as a likely s/w problem. In both cases I completely
> wiped the disk and installed from scratch...

foobar <> wrote:

> I have a 'sudden' 'random' reboot issue w/ my ABit ZM6 system (i440ZX
> chipset, Celery OC'd to 550, FSB100).
>
> I read somewhere a while back (cant' find it anymore) that a singel
> 256 stick is better than 2 128s and can avoid h/w problems like
> this...?
>
> Soooo... memory?

Do you have a good, local compute store (one of the medium-sized ones
with a bunch of components for self-builders)? They should have a memory
checker and a reasonably-priced stock of replacements. If that proves to
be the problem.


> Other possibilities? Power supply? CMOS battery? I dunno where some
> logical places to start might be...?

Power supply is a possibility (how old is it?). Don't think the CMOS
battery is the problem (usually interferes with booting, not causing re-
booting).


--
Jeff

================================================== =================
NOTE: Remove underscores from my e-mail address to reply personally.

Wow! All great posts and good keeper info here - thanks very much!

Yes, I have already pulled 1 stick and am running w/ just 128 right
now. So far so good. I purchased the original stick in '99 and this
second stick sometime within the last 6 or 9 months. I'll let it run
all thru next week and see if it does another 'WHAMO' reboot. I think
I tried this once before and don't think it ever rebooted before.

I don't know what Mushkin is likely to do here though if I call
them...? I'm not even sure I still have the receipts.

I'll disregard any concerns I had about the battery.

The PS is the one that it's had since I built everything back in '99
so it's 4 years old. It's like a 235W or 250W or something. The
voltages displayed in BIOS are probably within less than a 0.5V or
spec - I can check and post exact voltages - not sure if that tells us
anything. What should I be looking for on PS issues?

It's been so long since I have checked the voltages - I'd have to boot
and double check but I want to see it's voltage is pretty close to
'stock', maybe 1.8 or 1.85V?

I've not noticed any obvious visual problems w/ the caps but I wasn't
looking for anything either - I just had it opened up and on the table
and blew out some dust when I went thru things before installing W2K.
It's back in it's 'corner' but I'll double check w/ a flashlight for
any signs as suggested.

I do have memtest86 and have run it in the past including recently
(since this problem manifested) and it has always been fine. HOWEVER
just the other day I ran it again and did got some errors right around
the 1mb and 127-129mb area - maybe 2000 errors specifically in TEST 5
[Block Move, 64 Moves, cached]. That's strange because I hadn't seen
that before. I pulled sticks and re tested 1 stick at a time - got the
same error in similar locations but the # of errors dropped
considerably to only 10 or 20 errors. I've since adjusted some of the
CMOS settings and need to retest and verify if the problem was due to
a setting I had previously fiddled w/ or not. Strange.

I'm a bit confused about memtest86 - I've got some older systems too
and sometimes memtest has reported EDO memory errors on those and yet
they are rock steady just fine...? Is this generally considered a
pretty reliable tool?

Any good sites/recommendations that explain all the intricacies and
such on some of these BIOS settings...?

Prime95!? Hadn't run that since I built this system. I'll give that a
shot as well as retest w/ memtest86.

I do have 1 PC store that could probably test memory - we used to have
a bunch but they seem to be getting pretty rare around here these days
- not sure what's up w/ that?

---

Again, thanks for the great info and suggestions! I'll follow up w/ my
findings and see what happens. But I suspect due to the nature of this
type of problem - this may be a sloooow process.

-T

foobar wrote:
>
> The PS is the one that it's had since I built everything back in '99
> so it's 4 years old.

Power-transistors don't last forever.
Neither do caps, but they could last a few more years.
Have a look inside the PSU to check the caps and while you're at it,
clean out the dust - dust buildup could make some of it run so hot, that
voltages would be somewhat off.

Another thing - I also have an Abit ZM6 (somewhere) and I remember
putting thermal paste below the heatsink on the Northbridge.
There was none when I originally removed it to check.
A heat problem with the Northbridge could also cause "memory" errors,
although the memory sticks would be fine.

> It's like a 235W or 250W or something.

If you buy a new one, I would recommend an Antec.
I currently have an Antec PP-303XF powering a system with a T-Bred
running at 2000 MHz on an Abit NF7. Very low noise.
Extremely stable.

> The
> voltages displayed in BIOS are probably within less than a 0.5V or
> spec

They should be within ±0.2V of spec for +3.3V and +5V, (and within ±0.5V
for +12V - the +12V rail is not very sensitive to voltage out of spec
though).
Particularly, the voltages shouldn't be too low.
A system might still run seemingly "stable" with voltages out of that
range, but it would be very sensitive to voltage drops/hops - and would
either reset, lock up or exhibit strange errors occasionally.

> - I can check and post exact voltages - not sure if that tells us
> anything. What should I be looking for on PS issues?

Well, practically what you are experiencing right now - a not 100%
stable system.
Voltage out of spec indicates a defective PSU (Power Supply Unit).

> It's been so long since I have checked the voltages - I'd have to boot
> and double check

You can check the voltages with Winbond Hardware Doctor, downloadable
from Abit.

ftp://ftp.abit.com.tw/pub/download/fae/zm6.exe

Check voltages when running at full load - use cpuburn to do that;

http://users.ev1.net/~redelm/

> but I want to see it's voltage is pretty close to
> 'stock', maybe 1.8 or 1.85V?

Stock voltage(Vcore) for a Celeron 366 is 2.0V, but running at 550 it
would have to be overvolted to 2.2V (at least).
Below 2.2V it will probably not be stable, especially since it is now 4
years old.
Has it been running 24/7, or just some hours every day?
A Vcore that is low, compared to the Bios setting, indicates defect caps
or PSU.

> I've not noticed any obvious visual problems w/ the caps but I wasn't
> looking for anything either - I just had it opened up and on the table
> and blew out some dust when I went thru things before installing W2K.
> It's back in it's 'corner' but I'll double check w/ a flashlight for
> any signs as suggested.

Good, it could still be the caps.

> I do have memtest86 and have run it in the past including recently
> (since this problem manifested) and it has always been fine. HOWEVER
> just the other day I ran it again and did got some errors right around
> the 1mb and 127-129mb area - maybe 2000 errors specifically in TEST 5
> [Block Move, 64 Moves, cached].

And no errors in test 5, non-cached?
I didn't go any deeper into it, because I would wait and see whether
memtest86 reported errors.

> That's strange because I hadn't seen
> that before. I pulled sticks and re tested 1 stick at a time - got the
> same error in similar locations but the # of errors dropped
> considerably to only 10 or 20 errors.

Same (test 5, cached) error with both sticks, one at a time?
No errors in test 5, non-cached?
(Let's call them stick A and B)

> I've since adjusted some of the
> CMOS settings

Which settings?

> and need to retest and verify if the problem was due to
> a setting I had previously fiddled w/ or not. Strange.
>
> I'm a bit confused about memtest86 - I've got some older systems too
> and sometimes memtest has reported EDO memory errors on those and yet
> they are rock steady just fine...?

Have you also tried running the Prime95 "torture test" on those systems?

> Is this generally considered a
> pretty reliable tool?

Yes.
If memtest86 reports errors, it's because there is something wrong.
(no false-positives)
Memtest86 stresses the memory in a way that rarely occurs in everyday
use, so it will even find errors that might only occur once or twice a year.

> Any good sites/recommendations that explain all the intricacies and
> such on some of these BIOS settings...?

Tomshardware's BIOS Guide maybe..?

> Prime95!? Hadn't run that since I built this system. I'll give that a
> shot as well as retest w/ memtest86.

Well, now that we know memtest86 reports errors, we don't need it.
It is usually run to check CPU+Chipset+RAM stability.
If Prime95 and memtest86 had reported no errors, I'd have said it was a
software problem.

Jens C. Hansen [Odense] wrote:
>
> A heat problem with the Northbridge could also cause "memory" errors,
> although the memory sticks would be fine.

Minor correction;

"although the memory sticks would show no errors in another board".