can defective DIMMs kill good DIMMs?

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bruce56

I bought some used DDR2 DIMMs to match a pair what I had already. I inserted them into my good PC and it would not boot - no display, not even a beep error code.
So I removed the suspect DIMMs, and still my PC does nothing. Only after replacing the original DIMMs with a third pair did the PC boot.
Next I put the suspect DIMMs in a spare computer, and it gave beep code for
memory failure (has a different mainboard to the other PC). Also tried the original DIMMs that were good, and found they also give bad beeps. So it appears that I got some bad memory which furthermore damaged the original RAMin the nearby slots. I contacted the seller who swears on a Judeo-Christian storybook that they were A-OK when he posted them. They were wrapped in an anti-static bag.
I have been building and upgrading PCs for over 15 years, and have never zapped any modules. And both PCs were set at standard frequency and voltages.
 
I bought some used DDR2 DIMMs to match a pair what I had already. I inserted them into my good PC and it would not boot - no display, not even a beep error code.
So I removed the suspect DIMMs, and still my PC does nothing. Only after replacing the original DIMMs with a third pair did the PC boot.
Next I put the suspect DIMMs in a spare computer, and it gave beep code for
memory failure (has a different mainboard to the other PC). Also tried the original DIMMs that were good, and found they also give bad beeps. So it appears that I got some bad memory which furthermore damaged the original RAM in the nearby slots. I contacted the seller who swears on a Judeo-Christian storybook that they were A-OK when he posted them. They were wrapped in an anti-static bag.
I have been building and upgrading PCs for over 15 years, and have never zapped any modules. And both PCs were set at standard frequency and voltages.
Click to expand...

You can have DIMMs that are so defective, they burn the motherboard.
That's the worst kind of failure. (A DIMM capacitor failing short, on a
motherboard without OC protection, can do that.)

All it takes, is for one DIMM to jump on the bus while the
other DIMM is trying to do that, to cause problems.

So yes, there are a few failure modes that can have a widespread
impact. And, as you note, the testing procedure after an
event happens, can result in multiple other pieces of kit
getting toasted. For example, when you inserted the third
set of DIMMs, and got the "all clear" indication from your
motherboard, if the motherboard was damaged, you could have
had the third set toasted as well. That's if the DIMMs
damaged the motherboard in such a way, as to cause the
motherboard to damage subsequently installed DIMMs. There
have been some pretty expensive "domino effect" failures
people have run into. Usually, people figure it out, after
they've toasted a third set of something :-(

Paul
 
I bought some used DDR2 DIMMs to match a pair what I had already. I inserted them into my good PC and it would not boot - no display, not even a beep error code.
So I removed the suspect DIMMs, and still my PC does nothing. Only after replacing the original DIMMs with a third pair did the PC boot.
Next I put the suspect DIMMs in a spare computer, and it gave beep code for
memory failure (has a different mainboard to the other PC). Also tried the original DIMMs that were good, and found they also give bad beeps. So it appears that I got some bad memory which furthermore damaged the original RAM in the nearby slots. I contacted the seller who swears on a Judeo-Christian storybook that they were A-OK when he posted them. They were wrapped inan anti-static bag.
I have been building and upgrading PCs for over 15 years, and have never zapped any modules. And both PCs were set at standard frequency and voltages.
Click to expand...

What can cause memory to fail other than incorrect voltage, and what
other than the MB's initial draw on the PS to provide that final stage
of regulated memory voltages? All else being normal spec'd. When my
MB was giving me problems, the voltages registered not so far out of
the norm, but what was happening, I think, is the crappy MB capacitors
were straining like all hell. It was to the point of prematurely
wearing out PS units. So, even though everything is reading OK to a
novice looking at programs/sensors reporting voltage setpoints, it's
not really. Things are fluctuating way out of wack at some level
beyond those readings, and, meanwhile, I'm replacing power supplies
every year or two under piss-poor assumptions. When you test a car
battery for instance it's put under a load for a truer sense of how
voltage interacts with current. Not what it displays on a $5
multimeter. Same with those sensors to my way of thinking. How do I
know...I really don't. I just watch for the little abnormalities and
don't dismiss them if they're going to carry over or turn into a
bigger issue. I try and get the stuff right, good components, but
there's always something to watch because I'm a sucker for old-assed
gear when it looks good and priced right. Another thing. No computer
I've owned is ever the same. They've all got their personalities and
sometimes age into something else.
 
I bought some used DDR2 DIMMs to match a pair what I had already. I inserted them into my good PC and it would not boot - no display, not even a beep error code.
So I removed the suspect DIMMs, and still my PC does nothing. Only after replacing the original DIMMs with a third pair did the PC boot.
Next I put the suspect DIMMs in a spare computer, and it gave beep code for
memory failure (has a different mainboard to the other PC). Also tried the original DIMMs that were good, and found they also give bad beeps. So it appears that I got some bad memory which furthermore damaged the original RAM in the nearby slots. I contacted the seller who swears on a Judeo-Christian storybook that they were A-OK when he posted them. They were wrapped in an anti-static bag.
I have been building and upgrading PCs for over 15 years, and have never zapped any modules. And both PCs were set at standard frequency and voltages.
Click to expand...

It's possible that you have an insufficient power supply, which was at
the edge of minimal power requirements, and adding the additional memory
just took it out over the edge. Since there wasn't enough juice going to
any memory module, they may have all gone bad.

Yousuf Khan
 
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