3 gig DDR 2 SDRAM Failure; 4 mod = 2 mod (1 gig) + 2 mod (512 mb).

[aswan]

Motherboard: HT2000
processor: AMD Duocore
OS: Vista Home Premium

Last night I was logged in to "Second Life", when all of a sudden my computer screen went black. Mouse and keyboard were dead and the only thing I could do was a cold boot. Upon booting however the bios would not load. Initially I thought this was due to the bios itself and consequently I switched jumpers 2 and 3 to clear bios. This was to no avail.

Next I took out three (512+512+1 gig) of the memory modules and left one (1 gig) in place. Upon boot the computer started up again, I turned off the computer and tried adding one module at a time and booting, but the computer would not load bios. I tried various other combinations and found that 512 mb + 512 mb starts up windows. 1 gig + 512 mb would load up windows as well, plus I could start up internet browser (firefox) for a minute before it would fail. Any other combination does not yield success, and the modules are very volatile in behaviour. a combination of 1 gig + 512 mb + 512 mb rearranged loads up bios but fails while it tries to start windows.

A single 1 gig module in the first slot seems to be working fine up till now.
A single 1 gig module + a single 512 mb module loads up giving me 1.5 gigs but fails within the first two minutes.
Other combinations yield no success

Like a half our or an hour before the initial failure took place something peculiar happened, in Second Life I could suddenly move at the speed of light almost (without this being ghosting or lag) something I later linked to perhaps being related to the memory problem.

Any help would be greatly appreciated.

[JJ 3000]

What happens when you press the key to enter BIOS?

[aswan]

When I press del to enter bios I can enter the bios with no problem.

Another combination that seems to work is two modules of 1 gig in the first and third slot

I reckon I have these 6 combinations to choose from and so far none have worked while using all four modules

   A       B         C             D
1 gig   1 gig    512 mb   512 mb
1 gig   512 mb   1 gig    512 mb
1 gig   512 mb   512 mb   1 gig
512 mb   512 mb    1 gig          1 gig
512 mb   1 gig      512 mb   1 gig
512 mb   1 gig           1 gig          512 mb

**correction** while I was typing this up my computer blacked out again, so the 1gig+1gig in slot 1 and 3 doesn't work any longer. it's so strange that it worked for more than a half hr, and now failed twice already.

I'm wondering if any of this has to do with heat, even though it was never a problem before plus it's winter here no chance of overheating. the computer is not overclocked. the behaviour of modules are increasingly unpredictable.

So now I'm wondering if it's the modules that are corrupted or the motherboard, some combinations work for a while and other don't work at all.

[aswan]

I've tested the modules with an onboard memory test utility that comes with vista I guess, and it found no problems with the sticks. This seems to be correct because when I run only one stick on whatever slot it works just fine (up till now) but as soon as I put in two 1 gig sticks it won't work unless i put it in slot 1 and 3 and even then it only works for a couple of min. If I try testing the modules with the memory test it stops and goes black in the first few seconds.

[patio]

MotherBoard Manual

What speed are these RAM modules ? ?