Problems with Installing 4GB RAM on mid 2007 iMac

Hello XBrowns

What are the specs of the original 1GB modules in System Profiler, one thing that comes to mind is that maybe it's a 2008 model?

If the specs are correct, then install both new 2GB modules and restart holding the (Command, Option, P and R keys to reset the PRAM and NVRAM.

http://support.apple.com/kb/HT1379

Dennis

Hi, I'm having the same issue.

I bought 2 - 2GB chips from Crucial.com

Each one works independently with the current 1GB chip (I haven't tried either of them on their own... i think I'll try that next) But I can't get the computer to start up when both 2GB chips are in together.

I definitely have a mid 2007 iMac 20". I finally decided to up the RAM the other day... I just got the chips in the mail today.

I've tried resetting the PRAM and NVRAM but it's just not working with both 2 gig chips. When both of them are in, the Apple startup gong sound doesn't even play. The computer clearly turns on (fans are going... stuff's happening), but the screen stays blank and doesn't do anything.

Is this a common problem?... Or is it just a coincidence that there are two people with the same issue?

Coincidence.

RAM can be fussy.

I know that doesn't really help. You will have to talk with Crucial about getting replacement SODIMMs.

I am having the same issue and done all the steps from this post...

http://discussions.apple.com/message.jspa?messageID=10294662#10294662

At least I have 2GB now.

OK, I still haven't heard whether anyone has been able to solve this problem. I have the same problem and it is frustrating! Both of the Crucial 2GB chips (DDR2 SDRAM, 667MHz) are good. It doesn't matter which slots I use, as long as I put in a 1x1GB (original chip) and 1x2GB in, the system shows 3GB (as it should). However, as soon as I remove the 1GB chip and insert 2x2GB chips.... NOTHING, no starting ding and a blank screen. As others have said, the fans are running, but no screen, no starting ding, nothing. I hate taking it to an Apple store as it is well over an hour away. Surly someone out there knows the answer to this problem.

Well, at first thought, the issue clearly lies with the RAM. The startup chime is your Mac communicating to you that it has passed the Power On Self Test (POST) and has found usable RAM to continue the boot into Mac OS X.

The fact that it is not chiming is that, for whatever reason, the two 2 GB RAM bars together are not passing muster.

What does your RAM supplier have to say about the issue?

Dah•veed

Hi all,

i came across this thread when i fitted two 2GB modules and experienced the same problems.

So i rang Crucial (UK) and explained the problem and was told that there is a problem with a batch of memory modules which prevents them operating together but allows them to operate individually with the original 1Gb module.

According to Crucial UK, the problem should be resolved within the next week or so at which point they will exchange my 'defective' units for new ones.

Alan

It is not just Crucial. I also have the same problem with installing memory from Transcend. I ordered from Crucial initially and had the same problem mentioned here, so I sent them back to Crucial and asked for my money back. This is annoying as Crucial sent me these modules after they knew about the problem. Seems they are happy to take your money in the hope that you wont complain. As if that is going to happen.

It seems to me that it is not just a problem with the RAM but with the imacs themselves. So come on Apple, help out your long suffering fans here and give us a proper answer to this problem. And not answers like, memory can be tricky. I never had problems with installing RAM before.

i'm also having the same problem in my early 2008 mbp. i got 4gb of ram from crucial, i'm positive it's the right type, both 2gb will not work when paired with each other, however they do work when paired with the stock ram, and show 3gb. very frustrating

Having now spoken to Crucial (UK) i have decided not too wait for 'new' modules to be available but to send the memory back within the 30 day return period and get a refund. When i last spoke to them, they couldn't say when the corrected modules would be available so i now plan to look elsewhere but ask the question of incompatability problems in advance.

+It seems to me that it is not just a problem with the RAM but with the imacs themselves.+

How does this make any sense when one considers that Apple successfully specified, produced, sold and delivered all three iMac (mid 2007) models with an optional 4GB of RAM pre-installed?
In addition, Apple has, without issue, sold large quantities of that same RAM online and over-the-counter for customer upgrades. Much of all that 2GB, and the latest 4GB RAM, as usual, has been manufactured by Micron, the publicly owned U.S. manufacturing company parent of the Crucial direct sales division. The same type of RAM was also being provided to Apple by other manufacturers.

I received my two orders of upgrade RAM from Micron/Crucial even before I had purchased my 24-inch iMac, and it's worked great ever since I installed it. I also installed the second half of that order into my current MacBook, purchased a month after the iMac, and it's also been working great ever since. These are certainly superior Apple products.

Obviously there has been a change in RAM manufacturing design at Micron, probably due to their change-over to the costly, challenging high-tech 50nm and 40nm manufacturing technologies, and it is nothing more than Micron's problem.

Message was edited by: myhighway

Just to finish off my involvement in this thread, after discussing the problem with Crucial i decided to return the RAM to them and arrange a refund. I then ordered some more RAM from a different supplier (Offtek UK) which i have now put in to my iMAC and it is working correctly.

So it would seem the problem is with the Crucial / Micron memory?

Regards

Alan

Same problem. Just bought 2 x 2GB RAM modules for my iMac (24") from Crucial UK. Upon start up, all I get is a blank screen. Reinstalled the old 2 x 1GB RAM modules and everything works fine. Still not sure whether the problem lies with the RAM or the iMac ...