I bought a PNY RAM 512 MB, PC133, SDRAM. It is not compatible with my old RAM. I ran a memory test on just the PNY RAM, and the PNY RAM with my current RAM. The PNY RAM by itself passes the test. I ran it all night with the extended test scenario. When I combine the PNY RAM with my other RAM, it fails almost immediately. This is the second stick of PNY RAM I've received that has failed. The PNY RAM is listed at http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=111533&CatId=829. With the first stick, it was causing random corrupt files. I'll assume the second stick would do the same.

I called to complain about the second stick of RAM. PNY tech support said "nothing is wrong with the RAM I already returned". They also said if I return the second stick and there is "nothing wrong with it", then they won't send me any more RAM. They run TESTS on EVERY stick before it's sent out. Their quick test is more comprehensive than my 12 hours of testing. They said to run the test without my original RAM.

It's obvious the PNY RAM isn't 100% compatible as stated. It's obvious there "Lifetime Guarantee isn't. My questions is this: When I call to complain again about the PNY RAM, is there any meat to them saying, "It's not the PNY RAM, it's your old RAM that is the problem."

I'm already past the 30 day return. I have an ASUS A7V133A mobo which can handle up to 3 sticks of RAM, up to 1.5 GB.just how different are the RAM modules? Do the same tests on your old RAM pass just as well alone?The old RAM passes with flying colors when combined together. I didn't test the old RAM alone because it passes together. Does this matter?

I don't have the brand name handy at the moment, but the RAM is the same spec, SDRAM, PC133, 168 pin DIMM, 3.3v, unbuffered, and 4 clocks signals per dimm. The only difference is the old RAM is 256MB + 512MB and they are both different companies than PNY. The new PNY RAM is 512MB.Well you can't be sure unless you test each one individually... I've seen RAM act up like that... Also... I've seen motherboards be picky about which module went first... Did you put the largest module in slot 1? You'll have to test each combination of modules to SEE which is the culprit. Before you started swapping memory around, did you ground yourself? Even ESD that you can't feel can fry a memory chip. Also... what CPU are you using?

Also.. have you made sure it's supposed to be compatible? http://www.pny.com/configurator/

I've read where PNY is very picky about mixing modules of different manf.What kind of machine is it? Tere are problems with older machines and high density ram vs. the low density modules they came with.It was a custom built, ASUS A7V133A motherboard, AMD 1200 CPU. I was running some more tests yesterday and last night. It appears that only certain combinations of the RAM will cause it to fail when combined with the PNY RAM! Weird.

I have 2 sticks of 512MB and 1 of 256MB. I've tested the two 512's togther and they passed. I've tested the two 512's and the 256 and it failed. I'm testing the PNY 512 and the 256 right now. I'll post the results when finished. I'm also trying different slots on the motherboard in hopes that means something.The results boiled down to the PNY RAM will work with one other stick of RAM. I tried one other 512, one 256, and two different 128's. Can anybody explain that?

What was also weird, the PNY memory only failed on the LRAND test (random memory). It passed all of the other tests.

My mobo can handle any combination of single or double-sided SDRAM upto 1536MB.It's all down to tolerances which is why it's better to buy not only from the same manufacturer, but if possible, from the same batch.
Conventional electronics has been PUSHED to the very edge of it's frontiers by todays computers.