DDR3 - Some work; some don't

[topeagle]

I am been having a hard time getting memory to upgrade a series of Gateway SX2800-7 's

I have had best success with Kingston KHX1333C7D3K2/4GX memory. But some work; some don't. I finally noticed that the wiring diagrams on the actual circuit boards of the memory is different. There are two different distinct patterns. One always works; one never does. With heat-sinks on, it is hard to see totally but it appears that the ones that work have the pins directly to the right of the key-notch slot on the front have wiring going to them. The ones that do not work, don't have that.

They are the same model number on the ram but in volume, I find some that work (with the wiring one way) and others that don't (with the wiring the other way). Unfortunately you can't tell when buying; it is order and open and if wrong then return. I can now tell whether memory will work just by looking at circuit board.

Does anyone know what is going on?

 

[inzone]

Must be a factory defect in thier processing dye that actually makes the circut board these things are all made in Tiwan and China so they must be getting substandard quality control that's letting these pcbs slip by.

 

[topeagle]

It seems more like a design change with the same model number. I mentioned the Kingston memory because that at first had more that worked than did not, but now I am not seeing that. Now, almost all new memory does not work. But I have also had this with Patriot, Corsair and other less known brands. I have literally tried dozens of memory modules. What is maddening is that when you find one that works, the packaging (both the external and the labels on the circuit boards themselves) are the same. I have had techs at Fry's, Best Buy and Micro Center verify what I am seeing and they can't explain it either.

 

[topeagle]

I was able to snap a picture of working memory and non-working memory side by side. The DDR3 on the left works; the one on the right does not. You can look at the line traces just to the right of the key-notch slot and see what I mean about the ones that work seem to have the first lines connected and the other ones does not. Of course there are several other differences as well. Also note that the label on the memory has the same model number of memory.

http://www.eagleinnovations.com/MemoryPictures/DDR3_Working_NonWorking_Comparison_Pic.jpg

Does anyone know why this is? Thanks!

 

[inzone]

I'm willing to bet that those two sticks of ram were made at two different plants not only because of the differences in the PCB with the line traces but the sticker and heat spreader as well. If you look at the sticjer there is a line under the Figston name on the left but not on the right. Also the heat spreader appears different