System crash. Ram problems ?

[sarz]

Hey guys.

As the topic says I have a really strange problem lately.

I have a EpoX EP-8RDA6+pro motherboard (3 dimms) and had a total of 1 GB ram (1 x 512 Kingmax and 2 x 256 TwinMos). Everything worked fine until one day i decided to get a 2 x 512 kit (also TwinMos) to replace the old 2x 256. This worked fine for a few days until one night. I was watching a movie and had a sudden reboot.
The computer froze at the memory and IDE diagnostic screen. I manually rebooted and had the same problem.

After a while i decided to remove the kigmax module and run 1 GB dual channel. This also worked fine for a week or so and after that the restart-crash-restart cycle hit me again.

Now the only way i can actually boot normaly is by setting FSB at 100 (i have a athlon xp 2100+) and working only with 1 ram module. If i try to add another ram module the comp crashes again (doesnt matter if its dual channel or not or if its a 512 or 256).

I tried a bios rewrite, latest version, heat doesnt seem a problem at only 48" C, but nothing works. I also tried to mount the old 2 x 256 + 1 x 512 modules but i still experience crashes.

Tried to find a answer but had no luck so far

 

[raven_87]

Hmm. IDE diagnostic? do you have an IDE HDD?

If not, look at a few other possibilities; failing DIMM slots or perhaps voltage issues.

 

[sarz]

Yes i have a IDE HDD but maybe i phrased that a little wrong. Im talking about crash at the very first screen where you are promted to press del for bios. The comp freezes right when it says "calculating ram". Voltage is set on auto from bios and the strange thing is i checked every dimm with ONE memory stick to see if anything is wrong. The system fails only when i add more than one stick of memory or when i raise the fsb to 133 (and it should be 133 but it only works at 100)

 

[jsc]

A bad or failing PSU could cause this. Full system specs?

 

[sarz]

Well, as i said EpoX EP-8RDA6+pro mobo, AMD Athlon XP 2100+, 2 x 512 TwinMos DDR 400 kit, Radeon 9600 pro Graphic card and 2 IDE HDD 100 GB each.

And i managed to mount up both modules by lowering dimm voltage to 2.5 and single channel mode. Still, it doesnt seem very stable. Crashes still occour and i cant set fsb up to 133 as it should be

 

[raven_87]

voltage flux... possible motherboard failure. I'm not their too look at it myself obviously. But it sounds like either a combination or multitude of problems.

its called trial and error; sooner your start the sooner you'll be done.

 

[sarz]

Heh yeah its indeed trial or error. Anyway i forgot to mention the system loses stabilty on forced restart. For example power failure or pressing the reset button.

Also its seems DIMM 1 + DIMM 2 setup crashes instantly...DIMM 1 + DIMM 3 is pretty stable until the first forced restart.

Thank you for your help nontheless guys i will keep you updated in case i figure out the problem.

 

[raven_87]

Boots, then runs the POST and fails on the 2nd DIMM slot.

Sounds like you may have found your problem. Your board still under warranty? (though highly doubtful given age)

 

[sarz]

Unfortunaly its not in warranty.

But anyway, i figured what the problem is: system instability appears when i try to mount more than 1 ram stick. It works fine with just one..if i try to get another (dual channel or not) it crashes.

I'm blaming the memory controler or northbridge. I had a few power fluxes this week so maybe that explains it. Well....guess i need to get ready for shopping :-s

 

[raven_87]

Memory controller resides in the NB. If your going shopping, might as well be a whole new system.

 

[SiriusStarr]

Have you memtested all the modules involved? (If not in this machine, in another)

 

[compchipper]

I had an older biostar board (M7NCD Pro) that exhibited some of the same symptoms using matched pairs of memory (2X256 or 2X512). Your board is getting ready to crap out. Your memory is ok.

 

[The_OGS]

Sarz,
all this memory swapping around has clearly got your poor mobo (BIOS actually) all confused. What memory timing settings are being run or attempted?
And 2.5v to your memory won't help you out - you need ~2.65v, maybe 2.7v.
Your rig doesn't like mis-matched chips in dual-channel mode.
Mount the 2 x 512MB chips if they're both good - it sounds like one of them could be bad...?
Think - what has changed? It used to work okay didn't it, until you got the new RAM?
With 1 x 512 and 2 x 256MB before, depending on how you had it configured, you were probably not getting dual-channel mode anyway... Your probs may be from trying to get dual-channel mode up & running really for the first time.
Try each new TwinMos 512MB individually with at least 2.6v and all auto/SPD timing settings.
If both memchips work, the trick to getting your AMD rig to run may be to synchronize your memory/FSB.
Typically, 100FSB Athlons try to run memory @ 133MHz; 133FSB Athlons try to run memory @ 166MHz; and 166FSB @ 200MHz memory.
You should try to set memory speed the same as your FSB ie. 133MHz (which is 266DDR or PC2100 speed). You will need generous voltage and very relaxed, default/auto timings.
I have had problems with PC2700 memory in this situation, it doesn't like to run @ 166MHz in dual-channel, it runs fine @ 133MHz synchronous with the CPU though.
Hope this helps,
Regards