z3731 memory upgrade

I have posted this issue at least three times on this forum with no satisfactory answer! I have a 4gb Z3731 UR21P that was part of a limited production run that came with Windows 7 Home Premium when it first came out. I bought it because it had 2 open 2gb RAM slots in addition to the 4gb of 2gb chips that can be installed in it. I followed advice, purchased 4 gb from CRUCIAL according to their recommendations, opened the case, and was unable to get it to accept the chips they sent. I then got 4 gb more from Amazon via a German supplier that also claimed compatible chips. Still no joy. A local shop was able to get a 1gb chip recognized along with the 4gb they already had, but the chips they ordered did not work either. If there is anyone reading these forums who understands my questions, please answer:

Is there a special BIOS command the tells the system to do a memory timing test and set new values after a RAM upgrade, similar to the process the manufacturer's installation of the initial RAM? All the instructions I've found omit this techincal issue, but my experience with RAM goes back to days when I personally had to re-write the timing loop in CP/M 2.2 when I upgraded the RAM soldered into my Thompson's BIG BOARD kit to 4 mhz from 2.2.

Should I "give up" and replace all 8gb with an RAM KIT from Kensington (the orginal RAM manufacturer used by Acer when this system was built)? They should be able to match the specs from the origina, but ... I've already wasted money on two RAM purchases that didn't work, and my repair shop took back the chips they tried and refended any changers for the time the spent, which was considerable, since their technical folks "gave up!"

I would like to keep using this system, as I have replaced the original Hard Drive with a comparable drive when the one that came with it puked, and everything else works just fine. But... 8gb RAM is almost essential these days even if Win10 isn't installed.

Finally... has anyone put Win10 on one of these "touch screen" desktops? It has a dual core processor that is a lot faster than later models Acer shipped with the same basics.

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philetus

Crucial says it uses DDR3 PC3-12800 • CL=11 • Unbuffered • NON-ECC • DDR3-1600 • 1.5V. What did they give you.

If this is it, you can upgrade the bios to the current bios and see if that makes a difference, if your not already there. You can try Kensington memory, but I can't see how it would make a difference.

Any on this page should work.

http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&IsNodeId=1&N=100007611%20600551103

And upgrading to Windows 10 would have to be your choice. I wouldn't do it. Too many things seem to not work good.

ZundapMan

I don't have the chips in front of me, but the spec. looks correct. I think the newer chips have some subtle differences. I know I have the most current BIOS available for this unit. I'm suspcious that it contains some form of memory test/timing verification process when it is "initialized" for the hardware installed on the assembly line. Unfortunately, documentation does not seem to provide detail on how to check "new memory" probably because it assumes that the checks "will happen" when everything is powered back up, but you may need to shut off the built in battery or something like that to force it to re-check. Just a "hunch" since I've been wrestling with this off and on for two or three years.

When I got this machine, Win7(X64) as installed was "worse than useless" and it took me about three days and 70+ downloaded updates issued by Microsoft before it stabilized. I suspect it was an early, top of the line unit, given the processor speed...3.2 ghz

ZundapMan

Guess what? Both batches of RAM that did not work were slightly "faster" than the chips you identified. DDR3 133MHZ. On top of that Crucial sent me U-Dimm which may not be compatible with NON-ECC. Sheesh! I tried using all 133's already but apparently U-Dimm and plain DIMM chips of the same speed also "don't match".

ZundapMan

The Crucial site displays both 1.35 V and 1.5 V chips as "compatible" My US device is most likely running 1.5v memory now. I'm checking to see if they warrant the chips in a way that I can receive them, test by installing them, and if they work keep, otherwise return while retaining the original 4gb rather than replacing the whole bank.

I still keep wondering if there is a "refresh step" associated with memory upgrading that I/we have been missing, possibly one that involves briefly powering off the on-board battery that powers chipset memory?