Help!!! strange memory problem

[Jason]

Archived from groups: comp.sys.ibm.pc.hardware.chips (More info?)

hi,
I have got a strange memory problem that I have no idea how to
solve, hopefully one of you guys can give me some help.

I have an old AMD machine that's been running for 3+ years, it has
2 256mb of SDRAM in it, recently it starts to crash (blue screen) very
often, the error message indicates it's some kind of read/write
problem, mostly like HD failure or memory failure. I checked the HD,
doesn't seem like there is a problem, then I did some memory test, it
returned to me about 4000 errors. So I thought I'll take out one of
the memory chip see if both of them went bad.

So I took out one of them, everything seemed to be working, no error in
the memory test and windows doesn't crash anymore (slow though), and
then just for the heck of it, I put in the other chip in and took this
one out, surprisingly no error in the memory and everything works fine
under windows. But when I put both of them in, doesn't work again. Do
any of you know what could be the possible cause for this? thanks!

Jason

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.chips (More info?)

On 11 Mar 2005 18:32:32 -0800, "Jason" <yuecao@yahoo.com> wrote:

>hi,
> I have got a strange memory problem that I have no idea how to
>solve, hopefully one of you guys can give me some help.
>
> I have an old AMD machine that's been running for 3+ years, it has
>2 256mb of SDRAM in it, recently it starts to crash (blue screen) very
>often, the error message indicates it's some kind of read/write
>problem, mostly like HD failure or memory failure. I checked the HD,
>doesn't seem like there is a problem, then I did some memory test, it
>returned to me about 4000 errors. So I thought I'll take out one of
>the memory chip see if both of them went bad.
>
>So I took out one of them, everything seemed to be working, no error in
>the memory test and windows doesn't crash anymore (slow though), and
>then just for the heck of it, I put in the other chip in and took this
>one out, surprisingly no error in the memory and everything works fine
>under windows. But when I put both of them in, doesn't work again. Do
>any of you know what could be the possible cause for this? thanks!

At that age (3yrs ?) it could be the famous mbrd capacitor problem:
http://www.spectrum.ieee.org/WEBONLY/resource/feb03/ncap.html &
http://www.niccomp.com/taiwanlowesr.htm. See also
http://www.motherboardrepair.com/ for more info, pics & possible repair.
Check the caps on your mbrd for a domed head and/or leakage.

It could also be just heat from dust build up or a bad mbrd or power
supply.

--
Rgds, George Macdonald

 

[Guest]

Archived from groups: comp.sys.ibm.pc.hardware.chips (More info?)

On 11 Mar 2005 18:32:32 -0800, "Jason" <yuecao@yahoo.com> wrote:

> I have got a strange memory problem that I have no idea how to
>solve, hopefully one of you guys can give me some help.
>
> I have an old AMD machine that's been running for 3+ years, it has
>2 256mb of SDRAM in it, recently it starts to crash (blue screen) very
>often, the error message indicates it's some kind of read/write
>problem, mostly like HD failure or memory failure. I checked the HD,
>doesn't seem like there is a problem, then I did some memory test, it
>returned to me about 4000 errors. So I thought I'll take out one of
>the memory chip see if both of them went bad.
>
>So I took out one of them, everything seemed to be working, no error in
>the memory test and windows doesn't crash anymore (slow though), and
>then just for the heck of it, I put in the other chip in and took this
>one out, surprisingly no error in the memory and everything works fine
>under windows. But when I put both of them in, doesn't work again. Do
>any of you know what could be the possible cause for this? thanks!

This is not altogether abnormal. Two memory DIMMs load down your
memory bus twice as much as a single DIMM. As such, the signals on he
bus are a lot weaker, so while each DIMM may be able to send/receive
data fine on it's own, when they're both used the load on the bus is
too much and they can't get data through reliably.

Now, there may be an easy fix to this. Sometimes just reducing your
memory timings in the BIOS will do the trick. Most BIOSes have the
option to manually set your memory timings, and setting them to lower
(usually represented as a higher number) settings they default to
might be all that is needed. This doesn't always do the trick though.

Another thing to check for is what George mentioned, ie a problem more
with the motherboard than with the memory. That bad capacitor issue
did affect a LOT of boards from that era. I personally had a
motherboard that was purchased in early 2002 go bad on me due to this
exact problem. There were 3 or 4 main types of large capacitors on
that board, 1 of which was obviously bad. Where the other types of
capacitors looked perfectly normal, almost every single one of the
defective type showed some visible signs of damage (tops bulging out,
goop leaking out, etc).

-------------
Tony Hill
hilla <underscore> 20 <at> yahoo <dot> ca