Bad RAM or Wrong RAM?

[innocentsheep]

Just got a new 21.5" iMac today. Tried installing 2x4gb sticks today for a total of 12gb, but no matter what I did it wouldn't recognize. My first attempt it didn't see the RAM (only showed 4gb in About This Mac and system profiler listed the other slots as empty), next few times at reseating the modules I just got beeps when I turned it on. Works fine when I leave it stock.

This is what I got (x2): http://www.newegg.com/Product/Product.aspx?Item=N82E16820147068

I noticed that the stock modules were a few mm wider than the Samsung ones I bought.

So...bad RAM or wrong RAM?

EDIT: In case it matters, high-end 21.5" with the 2.8 i7 processor upgrade.

 

[Hellhammer]

The specs are correct. Try with the new modules only and put them in the place of the stock models.

 

[wxman2003]

Is this the base 21.5 inch, 2.5 Ghz model? On the Apple site it says upgradeable to 8 mb ram. Trying pulling the 2x2, and just install the 2x4 and see if that works.

 

[Hellhammer]

Is this the base 21.5 inch, 2.5 Ghz model? On the Apple site it says upgradeable to 8 mb ram. Trying pulling the 2x2, and just install the 2x4 and see if that works.

16GB works, or actually, even 32GB works but Apple advertises that it can only take 8GB.

 

[wxman2003]

16GB works, or actually, even 32GB works but Apple advertises that it can only take 8GB.

Those sneaky little devils!

 

[Gramp]

... next few times at reseating the modules I just got beeps when I turned it on.

I noticed that the stock modules were a few mm wider than the Samsung ones I bought.

Odd that you got different startup symptoms after reseating the new modules.

Did you take any anti-static precautions when installing?

If your O.E. RAM is also made by Samsung, the only difference is that the ones you bought are their "green" series.

Could that account for the apparent slight difference in width - they use less mica?

Might make inserting them less precise, but once seated shouldn't make any difference.

I read that those "green" packages are difficult to open, and you have to be careful not to damage the contacts if using a blade.

Unlikely to be 2 bad sticks IMO.

On the first try at inserting them, did they go in smoothly?

As already suggested, best to try the known good O.E.'s in the two suspect slots and see what happens - to rule that out first.

Then try other combinations.

 

[innocentsheep]

Odd that you got different startup symptoms after reseating the new modules.

Did you take any anti-static precautions when installing?

If your O.E. RAM is also made by Samsung, the only difference is that the ones you bought are their "green" series.

Could that account for the apparent slight difference in width - they use less mica?

Might make inserting them less precise, but once seated shouldn't make any difference.

I read that those "green" packages are difficult to open, and you have to be careful not to damage the contacts if using a blade.

Unlikely to be 2 bad sticks IMO.

On the first try at inserting them, did they go in smoothly?

As already suggested, best to try the known good O.E.'s in the two suspect slots and see what happens - to rule that out first.

Then try other combinations.

Definitely took anti-static precautions and the blade never touched the modules when opening.

The first insert they seemed to go in smoothly (heard a click). I assume the first time they just weren't seated properly, so I pushed them in further and that's when I started getting beeps at startup.

The RAM in the computer isn't Samsung from what I can tell.

Another question: my boyfriend has a Mac Pro from 2007 and he told me that, at least for his computer, you need to seat the larger RAM modules in the first slots followed by the smaller ones. From what I know that's not the case with the iMacs, but can anyone confirm?

 

[tommy060289]

I think it might matter since you are using different capacity sticks. I can't say for sure but I can remember when reading about iMacs from a few years ago that only took 3gb (2gb + 1gb) they told you stick the 2gb stick in bay 1 (the one nearest the front (screen side) so you should probay try the 4's in bay 1 and 2 and the then the others in bay 3 and 4

 

[innocentsheep]

Well I did all of your suggestions, and for some reason putting the larger 4gb sticks in the top slots worked. Now happily running 12gb of RAM. Thanks a lot Macrumors community!